piston | Welcome to the Asylum

Actually this article is a little late, I actually finished this engine up months ago, rode the snot out of it, and sent it home with its happy owner. Here are some pictures of the process. This is not nor is it intended to be a step by step guide. It just your chance to see something the average person normally never gets to see.
Let’s start with a view of the transmission and shift drum sitting in the now very clean engine case.

Add the crankshaft,

To keep the gaskets in place I use Hondabond 4 gasket sealer. This and similar products do not allow the gasket to squeeze out the way silicon based sealants sometimes do.

Here it is with the front half in place.

Next pic shows the reverse lock out lever (red arrow) and the shift actuator rod (gray arrow) installed into the rear crankcase half. The shifter rod passes completely through the crankcase to the linkage that operates the shift drum.

Back to the front of the engine here is the oil pump drive chain.

Now insert the camshaft, chain, and tensioner, be sure to line up the timing marks as noted in the service manual.

After adding the rest of the small parts that were laid out in a carefully organized fashion on the workbench put the front and rear covers back on.

The cylinder wear was very light so I felt safe just honing it out and replacing the piston rings.

Here’s a shot of the cylinder installed to the crankcase with the piston at top dead center

After everything else was back together I was ready to line up the timing marks and set the valve lash.

Check your service manual for the specification for your engine.

Everything else was just a reversing of the diss-assembly. Just keep putting parts back on until you have a working four wheeler again.

At the end of my last post about this the engine was sitting on the bench, so let’s pull it apart now. Start with the external accessories such as the starter motor, rope starter, etc.

On a full tear down like this I prefer to remove the clutches from the engine before removing the cylinder and head. That way there’s not any damage to the connecting rod or piston should I accidentally spin the crankshaft around too fast.

Of course the best way to remove the clutch nuts is with an impact wrench, but if you do not have one wedge something good and solid in the clutch gears to hold it still, and don’t forget the centrifugal clutch nut is reverse threaded.

You’ll need a steering wheel puller to get the centrifugal clutch out. It’s possible you could get lucky and break it loose with a rubber hammer, but I doubt it. Don’t try it because you can damage either the clutch, the crankshaft or both by hammering on the clutch.

Now you can see the timing and oil pump drive chain, along with the shifter meachnism in the front of the shifter drum.

After pulling all the little parts off the front making sure to not exactly where all of the thrust washers go, it’s now time to move up top and unbolt the rocker box.

Now set the pushrods off to one side and unbolt the head an pull it straight up to remove and then do the same thing with the cylinder

Here you can see me using the magnet to remove the lifters from their holes.

Next I popped the rear cover off after unbolting it. The magnets in the alternator will make it feel like it is sticking together so be careful.

In these lat 2 pics for the day you can see the alternator parts, the stator is in the top one and the rotor is in the bottom picture. Next time we’ll split the cases!

Peace Y’all