Tag Archives: transmission

Recon Re-Assembled!

Posted on by Motopsycho

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.

Let’s Split! (engine cases that is.)

Posted on by Motopsycho

Hello once again Ladies, Gentlemen and Russell,
When last I posted the engine was sitting on the bench with the top end and most of it’s accessories removed. The next thing I did was to remove one of the piston pin circlips and push the pin out far enough to remove the piston from the connecting rod.

If you don’t have an impact wrench available you should probably remove the alternator rotor before removing the top end. This is one job that really does require the factory special rotor puller. Fortunately they are not expensive and like the service manual worth every penny.

To remove the camshaft and timing chain first remove the camshaft bearing retainer and rotate the engine until the crankshaft is at top dead center and the timing marks on the cam sprocket and the crankcase line up. Now you can slide the camshaft out while working the cam chain off of the crankshaft. For the picture below I stuck the camshaft bearing retainer back into place after removing the camshaft so you could see how it fits.

Now it’s time to split the cases first remove all of the bolts and gently tap on the small projection around the cases and they should begin to come apart. If they do not easily come apart double to be sure that you have not missed any bolts like the one in this picture, that is inside of the engine where you might miss it.

With a TRX250 Recon engine I like to place it front side down on a workbench that allows me to place the protruding shafts through the bench so that it sits level. Then gently lift up on the rear case while tapping down on the transmission output shaft until it pops free. If you need to pry on the case to move it remember that you should never pry on any of the gasket sealing surfaces or around the cylinder hole. The outside of the engine mounting lugs is okay and there is on small place in between the lifter holes that can be used.
Just remember that if it requires any kind of force to remove something may be wrong and you should re-check everything before proceeding.

Here’s another shot of the transmission innards.

As you pull the pieces out of the transmission and lay them out on the bench like this be sure that you keep track of every single piece, all the washers bearings etc. and where they go in the assembly. I like to re-assemble them all back to their respective shafts as fast as possible. Keeping these parts in order is critical because just 1 misplaced or omitted washer can destroy the transmission and maybe the engine itself.

Here’s a picture of the failed gear so far I have only found one of the lugs that snapped off of it. The others probably drained out with the oil.

One last shot of the nearly empty crankcase, only the crankshaft and bearings remain.

Now I have to clean everything up good and order the required parts so it may be a week or two before you see this engine again.
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Peace Y’all