This old motorcycle is finally making it’s way back into one piece. It has new tires, wheel bearings, brake shoes, tapered roller steering head bearings, and anything else it needed to make it safe & reliable. Surprisingly enough even after 34 years of being beaten like a government mule, the engine & transmission are still in very good functional condition. This makes my life a lot easier.
Lets start with a quick look at the rear wheel & brake linkage before I started.
Yes I know I need my head examined for riding it for so long in this condition, but it was still a lot of fun!
I had to replace the brake rod, adjuster and the lever. The rod & its hardware are new old stock parts, & the lever was simply adapted from a junked motorcycle.
This is the exact same brake pedal that is shown in the picture above. I straightened it with a torch, hammer & anvil, before cutting the end off of an old dirtbike footpeg and welding it to the brake lever.
I had to buy an entire extra used carburetor to get a couple of parts that are no longer available separately, and I’m still waiting on my throttle cable to arrive from England so for now the carb is just sitting here until I receive the cable.
While waiting on some other parts it was time to start some body work.
Have I mentioned anywhere in this series just how incredibly nasty this thing was? Check out the red clay mud dried to the bottom of this tank.
The side covers are decent used parts that only required minor work to repair, but the tank itself is actually requiring a fair amount of body work to make look good.
It’s so tempting just to throw money at a project like this, and to a certain extent I have done that with the mechanical & safety bits. Since this is the 2o Foot Restoration the appearance of the machine will be handled in the most economical way possible, with a few cans of Duplicolor spray enamel. So many of the parts needed for this bike are either unavailable or priced beyond what I feel like spending on it, this is actually going to be a resto-mod more than a restoration. Plus the blue has to go, I want a tougher more subdued look for my trail bike so the color will be changed. No I’m not going to tell you yet, keep checking back (or just scroll down & subscribe) o see what it winds up looking like!
Finally started the repairs & upgrades to the old TS185. It was in dire need of new steering head bearings and brakes. A set of matching dual sport tires wouldn’t hurt either, along with a thousand other little things. So the day before yesterday I pulled it all the way down to a bare frame.
This is not going to be a show quality restoration by any stretch of the imagination. You may have noticed that the title of this post is The 20 Foot Restoration. If you’ve never heard that term before it describes a vehicle that looks really good from a distance of 20 feet or more, but when you get up close you can still see the dings & other imperfections.
If the skid plate had been removable I probably would have left the engine in the frame for all of this as it runs excellent. But the skid plate is an integral part of the frame, and the area between it and the engine was packed with a mixture of red clay mud & two stroke oil. Plus there was some damage to repair.
After getting it cleaned up reasonably well, I took some body hammers to it, straightened it up some, and the welded all of the broken bits back together. Then I hit it with the wire brush & sandblaster before shooting a coat of rattle can primer.
All of the frame bits & pieces are painted with some some cheap spray on truck bed liner, while parts such as the shock bodies etc. are being done in brake caliper paint. I disassembled the shocks & dropped the springs into a bucket of metal rescue to soak overnight. they’re not perfect but they look a lot better.
After 2 days of hard work this was my stopping point last night, this morning I am going out to detail the engine as much as I can without actually taking it apart. and will continue the reassembly of this poor old thing.
Boy life has been running wide open these last few weeks, There have been a few ups and downs but overall more ups than downs, so if you hear me complaining, just ignore me things are actually pretty good around here.
In my professional life (the one that pays the bills since I seem to be unable to sell enough motorcycle parts to survive) the last few weeks, my spare time has been devoted to studying to take the Certified Solidworks Associate exam and this past Saturday I took the test and passed it! So now in addition to my other software skills & certifications I am now also certified for Solidworks 3D CAD as well.
A couple of weeks ago I was trying to change out a 20 year old motorcycle tire when I bent a top of the line name brand made in U.S.A. tire iron. Instead of taking this as a warning I continued try to wrestle with the ancient rubber until I pulled a muscle in my shoulder.
So I decided at last to try to buy a manual tire changer. My Dad already had the Harbor Freight cheapie car tire changer that he used to change his truck, lawnmower, & small tractor tires and was very happy with it. He finally got himself a new truck and decided last week that being 72 years old, he didn’t want to fix his own tires anymore, and sent the tire changer home with me. I ran up to my local store and grabbed the motorcycle tire attachment. Unfortunately as delivered out of the box with the changes that have been made to the rim clamps on this latest redesign, it was useless. It might be capable of mounting a fresh new tire without modifications, but if you are like me and frequently deal with the treasures, (‘er junk heaps) that you have dragged up from old barns, cow pastures, and junkyards then it won’t be of much use to you either.
Since the next cheapest manual motorcycle tire changer I could find was 600 bucks it’s time to order a few parts & make a few changes. I will post more about those adventures later after I get all the parts in and put it all together. In the meantime I broke out my reciprocating saw and took care of the next pesky tire.
I like cutting up
We are heading into the heart of motorcycle show & rally season now here in the southeast, The Myrtle Beach Hog Rally, and Atlantic Beach Bikefest are the two biggies along the coast. For the vintage & antique bike lover, this weekend (May 2, 2015) in Panama City, Florida is Bikes on the Beach, in Spencer, North Carolina is the Carolina Classic Motorcycle Show, followed in two weeks by the AMCA Southern National Meet in Denton N.C.
All of us who work with metal have a common enemy, rust insidious and seemingly unstoppable it creeps into all the places we don’t want it to be, destroying our hard work, valuable treasures & expensive raw materials. About a month ago I did a review of Metal Rescue rust remover from Workshop Hero. The product worked very well & I have been pleased with it.
One thing we all know by now is that once you get the rust off of a piece of steel is that afterwards you have to keep it off. If you have ever removed rust from steel using any chemical method you may be familiar with a phenomena known as flash rusting. This occurs when you remove your rust free part from the solution (or the electrolysis bath), rinse it off and then leave it to air dry, only to find out that in a very short period of time, often well less than a day, the entire surface is covered in rust again. While there are a few finishes that actually require a flash rust coating to work such as POR-15 semi gloss black chassis paint & some gun finishing techniques, most of the time this is not desirable. Freshly machined parts are prone to flash rusting as well. In the past I have always just tried to coat all such surfaces with oil or grease to preserve them, and while this works it is messy, expensive & makes handling a pain. So when the fine people at Workshop Hero offered me a sample to test and to write about in this Dry Coat rust preventative review I jumped at the chance.
Just to keep thing honest & interesting let’s start by going out to the scrap pile and grab a rusty strip of 1/8″ thick x 1″ wide and cut six strips from it approximately 2 inches long. And then throw the strips into our bucket of Metal Rescue for an overnight soak. Yes this is the same solution that I used for the previous review, it has not been changed but it sure has removed a good bit of rust from various motorcycle parts.
Compare this to the before picture the rust is gone, I rinsed the parts with water and patted them dry with a paper towel
The plan for this little experiment is very simple to coat 3 of the strips with Dry Coat and allow to dry according to the instructions. Then I placed one coated test strip and one un-coated control strip paired together in 3 different locations around my property. This was on March 14th, 2015.
According to the company website it should give up to 2 years of protection from rust for steel parts stored indoors. The first two steel strips I left here in my office, literally indoors. The next two strips I placed on a ledge in the uninsulated, drafty humidity plagued old horse barn that I have converted into my workshop. Now this is definitely indoors out of the sun and the rain, but temperature swings cause enormous condensation problems that leave all of my bare steel tubing, rods, flat bar etc. coated in surface rust if they are not fabricated into useful items & painted quickly. If it can work here it should work at any other indoor location.
The final two pieces I stuck in a semi-exposed outdoors location. Let me be perfectly clear about one thing, this product is rated for indoor use by the manufacturer, if the coated strip rusts this is not a failure of the product, it’s just that an extremely curious cat wanted to push the limits. When I say semi-exposed, the two strips in the picture below are lying on the control enclosure of the solar panels that provide the lighting for my workshop. The solar panels are about 18 inches above them but they are exposed to the weather from 3 sides.
Just over 4 weeks later on April the 6th, 2015, I gathered all of the test strips together & photographed them. The parts that were coated with Dry Coat are on the right.
I decided to flip the pieces over so you could see both sides.
Now lets look at some close up pictures. Here’s the samples that I left in my office. The part on the left is well on its’ way back to the original rusty appearance, but the part on the right is not. You can clearly see the pitting from the original rust before treatment, but not any new iron oxide formation.
This next sample is the one that I really wanted to check after a month in the old barn with a typical South Carolina late winter/early spring weather pattern. It is not unusual at this time of the year to have temperatures swing from 15-20 degrees Fahrenheit up to nearly 80 and then back down again in the space of a day or two. Of course when the frost melts in the morning it will sometimes look like rain inside of an uninsulated metal building. You can see the difference that this made when looking at the untreated part on the left, it’s a lot rustier than the control strip that was left in the house. Once again you can see that the coated strip is still rust free, even in the pits left behind by the previous rust that was removed at the beginning of this test.
The outdoor test strips are next, the control strip on the left is quite rusty. The test strip on the right has developed a tiny bit of rust down in the existing pits in the metal. It still looks a lot better than the un-coated strip. Just remember Workshop Hero’s Dry coat is sold for indoor use and these last two test strips were just me satisfying my curiosity. The two pieces of steel shown here, have been rained on several times, and subjected to near daily freeze/thaw cycles. I am still pleased with the results and wouldn’t have problem recommending this product to anyone.
I did download a copy of the Material Safety Data Sheet for this product so that I could see if there was anything in it that required any special protective equipment beyond the usual safety glasses and gloves. It is non toxic, non-flammable, and does not require any special disposal precautions. I didn’t see anything about welding two pieces of coated steel together so I contacted the manufacturer’s representative, and was told that they suggest washing any parts that are to be welded with soap and water first. The coating is 3 microns thick and probably wouldn’t interfere with most welding or cutting processes, but it would be wise to follow their guidelines.
So who needs this stuff? Obviously those of us who restore or repair old motorcycles, atvs, tractors & automobiles. Also machine shops, especially those of you who are storing & shipping items like re-bored steel cylinders, crankshafts, and other bare steel parts. Steel fabrication shops & o.e.m. manufactures of steel plant equipment, platforms, vehicle parts, or anyone else who stores bare steel either as a raw material or a finished product and needs an inexpensive solution for temporary prevention of rust, without having to deal with a hazardous material.
Both Metal Rescue and Dry Coat are available in a wide variety of sizes ranging from small bottles, 5 gallon buckets, 55 gallon drums and even 330 gallon totes for industrial users. As I said this is not permanent rust protection but it beats using expensive, messy, and hard to remove paints, oils and greases just to keep rust off of steel for a short period of time until you can use it.
Product recommended. I am going to place all of the test strips back in the places where I had them and will check on them over time. If anything changes I’ll be sure to let you know.
Since I first posted this a couple of days ago it was pointed out to me that this article was not quite as beginner friendly as my normal do it yourself articles about explaining WHY you do some things. So if you don’t know the difference between a single leading shoe brake & a twin leading shoe brake or even how to identify which one you have or just to learn how they work please go to More About Vintage Motorcycle Drum Brakes and then come back to this page.
Twin leading shoe drum brakes are the ultimate development of motorcycle drum brakes. By using two lever arms and two cams to raise the leading edge of the brake shoes into the rotating drum they were able to generate a greater stopping force than a standard drum brake which pushes the leading edge of one brake shoe & the trailing edge of the other shoe into the drum. It was discovered early on that the shoe with the leading edge being forced into the drum generated much more friction than the trailing shoe. So until the development of powerful reliable disc brakes in the 1970s the twin leading shoe motorcycle brakes were pretty much the ultimate performance set up. Even after their performance was eclipsed by hydraulic disc brakes they were still considered adequate for small & medium sized machines right up into the early 1980s. Today there are still a few low end bikes fitted with drum brakes on the rear, but they are of the standard type, as even the low buck machines rely on powerful front discs for most of their stopping power. As far as I know today twin leading shoe motorcycle brakes are only found on antique, vintage, and custom bikes.
As always don’t forget that you can enlarge any picture on this blog by clicking on it.
What we are going to look at today is an example of what may be the last of the of the factory installed twin leading shoe motorcycle brakes. The nasty cruddy looking part you see above is from an 81 Honda CM400E. The “E” stood for economy. The CB & CM variants of this bike got disc brakes on the front. By 1981 these were considered obsolete and were used on this model as a bit of parts bin engineering to meet a price point. This particular front wheel & brake backing plate had been painted at least 3 times in different colors What you see in the picture above is after using some aircraft peeler & some light soda blasting to clean it off a bit. Then I disassembled it and and dropped all of the chrome bits in the Metal Rescuetub and put the rest of it in the parts washer before wire brushing the backing plate. Please note, if you are doing a restoration you do not want to wire brush aluminum parts like this but this one is going on a rough edged custom and the brushed finish will be perfect for it.
This is an exploded view giving you a look at the typical parts of a front hub using this style of brake.
On this one I will not be reinstalling the speedometer gear as my plans call for a custom electronic speedometer. The first thing to do is apply a light coating of high quality grease to the shafts of the brake cams and push them into the backing plates.
Second part is to put the clean, lightly oiled felt seals into place as illustrated below. While I am sure there is probably a specified oil for this I’ve always just used whatever was handy in my oil can and have never had any trouble. That being said I am not responsible for any trouble you may have if you do not research and use the factory recommended oil.
Third step here is to slide the washer with the wear indicator tab back down onto the brake cam over the felt on the side that you removed it from which should have a pointer cast into it like in the picture below. This little part has splines and has an alignment groove so that it will only fit one way. It it doesn’t just just slide back on you have it turned the wrong way and need to move it around the until the wide spline lines up with the wide groove.
A plain thin washer slides down to cover the felt on the other side of the axle hole.
The external return spring is dropped into place next.
On of the really nice thing about most old Japanese bikes are the presence of dots on the brake cams & arms to help you line them up correctly the first time.
Put the arms on one at the time aligning the dots. I normally have brake rod loosely installed between the two arms before assembly just because I think it is easier than connecting the two brake arms afterward. If it is easier for you to do it the other way then that is fine too.
Do not tighten the lock nut on the brake arm yet! Install the brake shoes first!
Adjust the brake rod as necessary to get both shoes to move at as close to the exact same time as possible. If you are a real demanding performance nut build yourself a jig and use a couple of dial indicators to ensure that the pads are moving together exactly. For the vast majority of us eye-balling it will work fine and any teeny little mismatch that occurs will be wiped out within a couple of stops
Now you can tighten down that lock nut. Here’s a little video to show you how the cams move the shoes when the brakes are actuated.
Now its time to get to work on the rest of the front wheel so that it can be installed on the front of Project wAmmo!
For this ‘Psyco product review let’s checkout Workshop Hero’s Metal Rescue
rust remover. In the past I have always used good old phosphoric acid for removing rust. In fact I have a 15 gallon tank of the stuff carefully stored away for cleaning old gas tanks & stuff like that. It really removes the rust quite well but it is also toxic, smelly and will corrode the base metal while removing the rust. To use it requires rubber gloves and eye protection.
Last year at the VMA swap meet in Eustis Florida, I bought a gallon of Metal Rescue from a vendor and brought it home, then I poured some out in a small container & dropped a couple of extremely rusty parts in it and left them overnight. The next day they were a little better but not as good as I hoped so threw them into the acid tank and stuck the Metal Rescue on a shelf under the workbench until last month (January 2015).
I’m in the very beginning stages of ruining a wonderful dirtbike by restoring it, so I decided to try the Metal Rescue on some of the chrome bits that really needed cleaning up. First I got a good bucket large enough to hold the parts with a good fitting lid to seal it up and poured the entire jug of rust remover into it.
After waiting a day I opened it up and this is what I found, meh give it another day.
This is a picture of the same after 3 days, I am not a happy camper at this point.
So I pick up the jug to look for a way to file a complaint and read the part of the instructions that says; “For best results, use at room temperature (68°F or 20°C) or above. Metal Rescue™ works optimally at room temperature (68°F or 20°C) and above, so it may require heating in cold temperatures.” Looks like using it in an unheated shop in January is out of the question unless you live closer to the Equator than I do or on the opposite side of it.
Determined to get my money’s worth out of this product I carried the bucket into the house and put it in the laundry room to warm up. When I checked on it the next day 90% of the rust was gone and on the fifth day of soaking the heat shield looked like this!
The rust was completely removed from both sides and I was very impressed. It probably would have helped a lot if I had read the instructions first. Since then I just keep this bucket of Metal Rescue in a safe place in the house. It is chemically safe with no hazardous ingredients and if you take care to ensure that no hazardous substances get into it, Metal Rescue can be safely disposed of in most sewer systems but check your local laws first.
To give you an idea of how much I like this product, I bought some more and put it into the bucket with what I already have. With the solution at room temperature it took less than 24 hours to clean up this headlight ring to the condition that you see here. Plus I was able to leave it assembled with all of the plastic parts & springs while it soaked something you would not dare do with acid.
The instructions do warn that if you leave plain steel parts in the Metal Rescue
too long that it will turn them dark after removing the rust. Plated parts don’t seem to be affected by this. The screws in the picture below illustrate this. Since I am going to be re-coating these screws it’s not an issue for me, but if you are restoring something that calls for a natural metal finish you should be aware of this.
What’s the bottom line, is it worth 25 -30 bucks a gallon? Yes, especially when you consider that if properly stored it can be used over & over combined with the fact that it is biodegradable and contains no VOCs, solvents, acids, bases or hazardous ingredients. Just be sure you read the dadgum instructions on the jug first. It really does work much better when it is warm.
Peace Y’all
It’s time for another Project wAmmo CM400 update. Let’s start with my confession that I lost interest in the project for a little while and was really short on time for it. Had some issues with getting the frame sandblasted so I wound up bringing it back home and hit the frame with some paint remover and went over it with my little hand held sandblaster before coating it with spray on truck bed liner. Did the same thing for the tank before brazing up a couple of damaged spots on it and sealing it with Caswell Epoxy Gas Tank Sealer. I also wound up replacing the fork because I was unable to identify the one that was on it to get the proper repair parts so I replaced it, and installed a set of tapered roller steering head bearings for good measure.
I got the modified Harley solo seat covered in olive drab Cordura fabric to match the overall theme planned for the bike.
Even though the engine would start and run okay, compression on the right cylinder was consistently 50 psi less than the left cylinder. Even after adjusting the valves (click here for the proper procedure) which didn’t help, and putting some oil in the cylinder to see if it would come back up temporarily indicating worn rings, the right side was still 50 psi lower than the left side so I went ahead and pulled the engine apart for a top end overhaul.
The problem turned out to be that the oil rings were frozen to the piston and the gaps were aligned on the top 2 rings preventing them from sealing. The downside to this bike originally being such an artistically created “natural” ratbike is that it was incredibly nasty. Here I am soda blasting the cylinder to clean it. Yes that is the cheap hand held sandblaster
and it works just fine with blasting soda, so if you’re on a budget & just need to clean a few small parts without damaging them the way sandblasting can try this. Just do not hit any gasket mating surfaces with the soda.
Once everything was cleaned & honed I taped off the mating surfaces so that I could spray on some Duplicolor cast iron gray engine paint.
The original clutch cover will be replaced with this good used one and since I was not splitting the cases for a full overhaul I sealed up the bottom half of the engine with duct tape so that I could degrease it and remove the existing paint.
Since the head needed a good clean up, it became the subject of a head service tutorial that you can read by clicking here. The next picture is of the original pistons with new rings ready for the cylinder to be re-installed. The blocks of wood held the pistons up and level while beautiful assistant slid the cylinder slowly into place while I compressed the rings.
This looks a lot better than the before picture doesn’t it? Once I got the head back on it was time to line up the timing marks for the crankshaft & camshaft as shown below and put the camshaft back in.
Afterwards it was just a matter of putting the rest of the parts back on and torquing everything down properly. Don’t forget to fill the oil pockets under the cam lobes with oil before putting the rocker box cover back on.
The engine is now ready to reinstall, I am going to leave the rotor cover off until later, ditto for the new clutch cover.
Now the engine is sitting back in the frame. The intake spigots are new replacements for the damaged originals.
I like puzzles
Now its time to sort out the wiring harness. Sometimes it is easier to start from scratch but for right now I am going to attempt to reuse at least some portions of the factory harness.
Normally on a custom motorcycle one would attempt to hide such parts as the regulator rectifier but since I am going for a post apocalyptic paramilitary look on this machine it is bolted to the side of the rear fender out in plain sight.
Once I get the wiring sorted out and get the wheels back on it’ll be time top restore this set of CV carbs. I will probably do an in depth post on that process when the time comes.
D.I.Y. motorcycle head service is possible for the home mechanic at times, under the right circumstances. Of course if you are one of those fortunate individuals who happens to have a fully equipped machine shop and know how to use it you can do anything. But for the ordinary person restoring an older motorcycle or atv that wants to save a buck or two it is still possible to do an acceptable job provided certain conditions are met.
My patient for this job will be the CM400 that I used for the valve adjustment tutorial a couple of weeks ago. After adjusting the valves and putting oil in the cylinders it still had about a 45-50 psi difference in compression from the left to right sides so I pulled it apart for a top end overhaul. It turns out that the right cylinder had oil rings that were stuck from sitting and that the gaps were aligned on the other two rings.
Before disassembling it, I cleaned the head fairly well and removed the carbon from the combustion chambers. This makes handling the parts much nicer and inspection much easier. No matter what method you use to remove the carbon do not allow any type of abrasive or wire brush or scraper to contact the flat sealing surface of the head. Yes I know you may have to use some type of scraper to remove the gasket residue from the head but be very careful not to scratch or gouge it in any way. I actually used soda blasting to clean this head but made sure not to hit the mating surfaces with it.
Now I must make a couple of quick disclaimers here. First there are some defects that if discovered during the inspection process that will mean you need to take your head to a machine shop to be repaired anyway. Second, unless you own a set ball micrometers to check them with, you will basically be guessing that the valve guides are okay based on the condition of the valve stems. Chances are that if like me, you are working on something old but with relatively low mileage they are okay BUT it is not guaranteed and excessively worn valve guides can cause oil consumption & smoking even with new seals. Third, this is not the high performance option, if you are building a hotrod and looking to squeeze every last drop of performance out of it you can then I suggest you contact a reputable high performance machine shop for a good 5 angle valve job and new valve guides. This is to get your old heap running as good as possible for the least amount of dough you can spend. The fourth and last disclaimer is to always put safety first in the shop. You will be dealing with strong springs under compression. There is a chance that a tool could slip releasing a spring to go flying out at high speed and hit you or to pinch your fingers between the spring & the tool. Only use a good quality valve spring compressor
in good condition, make sure you read the instructions that come with it, & wear some eye protection too.
Even so there are some specialty tools you will need to get if you do not have them. In the picture above at the bottom center the thing with the two suction cups on it is a valve lapper with 2 tubes of grinding compound one coarse & one fine. Moving clockwise around the head are the valve spring compressor, a caliper dial or digital whatever you have, a light rubber or plastic hammer just in case something needs a tiny bit of extra persuasion, a micrometer (if you don’t know how to read a micrometer you can either learn how or just buy a digital one.) Next item to the right is a pick up magnet and a flat screwdriver, a few pertinent pages photocopied from the service manual and a new gasket set with valve seals. If you want to learn to use a micrometer watch the 2 videos below.
Set your valve spring compressor into place over the first valve you wish to remove and turn the compression screw inward until the spring is compress enough that the valve keepers either fall out or you can reach in with a magnetized screwdriver and pull them out.
It is very important that you keep your valves, springs, & other parts together so that they can be reinstalled in the same opening from which you removed them. This is especially critical for the valves as they wear into their valve guides and seats as the engine is operating. If any of the valves do not come out, or if removal is difficult you may have a bent or seized valve, put everything back together and find a good machinist. The cure for a damaged valve requires replacing the valve & seat as a unit. The valve guide drivers and reamers required for this job are really a bit much to purchase & learn to use for just one head.
Once you get all the valves out give the head a good visual inspection looking for anything that looks galled, burnt, or cracked
Be sure you check inside the ports to especially around the valve guides. Next check the valve seats which are the hardened steel inserts around the outside of the large holes in the combustion chamber. If any of valve seats 0r guides are burnt, badly scored or pitted , have cracks in them or easily visible excess wear then you need to put it back together & take it to a competent machinist
If all looks good make sure the head is not warped beyond acceptable limits. for this you’ll need a good straight edge and a feeler gauge in whatever size your service manual specifies
Place the straightedge firmly across the head in several locations and try to insert the feeler gauge between it and the heads gasket mating surface. If it goes between the two anywhere then a machinist will need to shave the head to level it back out.
Now it’s time to grab the micrometer and check the diameter of every valve stem in several places up & around each one. If any of them are worn beyond the service limit, chances are the valve guides are shot too and this is no longer a normal do it yourself job. Double check them for straightness at this time also,
After that get a caliper and measure the extended length of all of your valve springs. Replace any that do not fall into the specified range for your motorcycle.
Once the inspection process is complete and you are satisfied that all of your parts are in good condition & can be reused go ahead & clean the valves & guides thoroughly. Most of the time you can just scrub the intake valves clean in the parts washer, but the exhaust valves usually have a hardened scale stuck to them so I use a brass wire brush to clean them with. For the valve guides I use a gun cleaning brush, but any small round brush with plastic or brass bristles that fits through them will do. I try to avoid using brushes with steel or stainless steel bristles on parts like these because I only want to remove the grease, carbon, and scale without affecting the base metal.
Pick out whichever valve you want to start with and put a small amount of valve grinding compound around the head of the valve on the surface that contacts the valve seat in the head, and place that valve back into the hole that it was originally removed from. Grab the valve lapping tool & stick one of the suction cups on it to the valve like this and then rotate it back & forth to clean the mating surface. The most efficient way to do this is to hold the lapping stick between your palms and pretend you are trying to start a fire with it. Stop occasionally to check on your progress and replenish the lapping compound if needed. I use a coarse compound to start with & then switch to fine grit, but it is possible to make do with just the fine grit if that is what you have.
Stop and inspect rather frequently, you are not trying the grind the entire surface of the valve & seat flat. What you want is a uniform,well polished shiny ring all the way around the valve & seat at the point where the two meet. Once you have that, to keep polishing is just putting unnecessary wear on your engine parts. It should only take you a few minutes per valve to accomplish this, so keep going until you have all of the valves done.
With all of the valves lapped you now need to wash them and the head again and completely remove all of the valve grinding compound so that it doesn’t make its way into your freshly overhauled engine and grind up parts that don’t need it. Then open up your gasket set and find the valve seals. I have the seals for this engine laid out above.
The two larger one are for the exhaust valves and the four smaller ones are for the intake valves.
Once you have all of the seals into place it is time to start reinstalling the valves remembering to put each valve back into the hole that you removed it from to start with. First push the valve back into the hole.
It should go in smoothly, make sure that it doesn’t push the new seal off of the valve guide. Put the matching valve spring(s) and retainer back into place over the valve stem.
You will have to carefully hold the retainer while you put the valve spring compressor into place to compress the valve spring(s).
Compress the springs until you can see the grooves for the valve keepers well enough to reinstall the keepers.
Put a thick coat of grease on each retainer to stick it to the valve stem when you put it into place.
If at all possible use a pair of tweezers or needle nose pliers to put the keepers on the valve stem. If you find that you must use your fingers to get them both into place be extremely careful and make sure that the compressor is securely clamped and not going to suddenly pop loose and crush your fingers while you are positioning the keepers. You have been warned.
When you have the keepers in place on the valve stem then slowly unscrew the clamping screw and if necessary keep the springs and retainer straight as you release the pressure. Remember if your compressor has a release handle on it like mine does, do not use it to clamp & release the valve springs. Always use the clamp screw. The release handle is there to allow you to move it from one valve to another without having to fully unscrew the clamp every time. When you have fully released the pressure & moved the clamp your vale should look like the picture below with both keepers trapped securely between the retainer & the valve holding the whole lot securely together.
Repeat these steps until all of your valves are securely reinstalled in the head.
I have tried to be as honest as possible with you about the possible pitfalls and risks of D.I.Y. motorcycle head service, but if you are willing to take your time, check everything carefully, and work in a meticulous fashion there’s no reason that you cannot give it a shot. Just be willing to take the risk of trying on your next restoration or overhaul and you’ll find yourself having that much more satisfaction with your handiwork once the engine is up and running.
Of course since I want this one to look as good as it works I covered up all of the mating surfaces & plugged all the ports before spraying my favorite ceramic filled engine paint on it. If you need tools and supplies just visit my webstore’s tool sections and search for what you need. If you can’t find something there let me know & I will point you in the right direction even if it means sending you to someone else.
Today I’m going to show you how to perform a Honda CM400 valve adjustment. This basic procedure covers 1978-81 CM & CB400T Honda twins. This engine is from a 1980 CM400. Please refer to a proper CB/CM400 service manual to verify the exact procedures & specifications for your motorcycle. I will give the valve lash & misc. other tune up specs at the bottom of the page.
Gather up the tools you will need along with a copy of the appropriate service manual. Please note that it is not necessary to remove the engine from the motorcycle to perform this procedure, I already have this engine out so that I could do some some fabrication work & painting to the frame. This is the long delayed Project wAmmo bobber that I should have finished months ago, but now I am back on it with a vengeance. You will need to remove the fuel tank, gear shifter, and whatever other parts are necessary so that you can remove the valve cover & the left side crankcase cover. Once all of that is done then remove both sparkplugs.
After you remove the spark plugs, switch sockets & turn the engine in the direction indicated by the arrow on the alternator rotor. The big rusty flywheel looking thingy you see in these pictures for those of you who have never seen one before. This one had to have some of the rust sanded off so that I could see the markings on it.
Turn the engine and watch for the intake valve rocker arm on the side you are adjusting to move down and then back up. These little Honda twins have a 3 valve per cylinder layout with 2 intake valves & 1 exhaust valve per cylinder.
Once the intake rocker arm returns to the top continue to turn the engine slowly and line up the next “T” mark on the flywheel with the pointer on the engine case, as it comes around. If the exhaust rocker arm starts to move you have gone to far & must circle the engine all the way back around & start over. Do not turn the engine backwards to get to the timing mark if you miss it.
Then verify that the piston is indeed at top dead center. On this engine it is fairly easy to do just by looking into the spark plug hole.
With the piston at top dead center for the cylinder you are adjusting both the intake & exhaust valves should a little bit of play in them unless the engine has severe wear or improper maintenance that has caused valve recession which will close up the gap. Too much lash is also detrimental to your engines performance and will cause your engine to tap very loudly. Too little lash will eventually lead to a burned valve if it doesn’t close completely.
Loosen up the lock nut for whichever adjuster you choose to start with, here I am starting on the exhaust side.
Then insert the proper size feeler gauge, loosening the adjuster with a flat screwdriver if needed.
Then carefully tighten the adjuster screw & lock nut until the feeler gauge is able to be removed & re-inserted with just a little bit of drag, but the next size larger feeler gauge should not fit. It will be necessary to hold the adjuster screw with the screwdriver as shown below while you are tightening the lock nut. Be sure to recheck your lash after you tighten down the lock nut for good, sometimes you may have to readjust to compensate for the adjustment screw moving when you torque the lock nuts.
Once you have all of the valves adjusted properly replace the engine covers being sure to inspect & replace all gaskets & seals as needed.
Valve lash and some miscellaneous tune up specs are below:
2014 was a terrific year with over 43,000 page views in the last 12 months. A big thank you to all of my readers! If you have an appropriate product to advertise or if you sell a motorcycle or motorcycle related product that you wish me to review, send a message using the contact form on my about page. Should you be in the mood to purchase some motorcycle parts or related gear be sure to check out Motopsyco’s Parts & Supplies.
In the meantime I resolve to keep on keeping on!
Peace Y’all
. The product worked very well & I have been pleased with it.
& some 
. I also wound up replacing the fork because I was unable to identify the one that was on it to get the proper repair parts so I replaced it, and installed a set of tapered roller 
Welcome to the Asylum 