Honda Rincon 680

I got back to work on the Honda Rincon that I started on a few weeks ago.

I am installing a new cam shaft in the engine.  The first step is to press the sprocket off the old one.  I do not have a hydraulic press, but with a good setup and a careful hammer you can get it done.  This photo shows the cam supported by a notched plate under the sprocket.  The yellow thing is my "anvil".  It is a large cast iron counter weight off of an old front end loader.  It weighs around 100 pounds and makes a great foundation to pound on.

A few careful swings with a 4 lb hammer and a punch and the sprocket came right off.  Next thing to do is move the bearing to the new shaft and "press" the sprocket on.

Tomorrow I'll install it in the engine and finish the job up.

Rincon 680

 I finally got back to work on the Rincon 680.  I pulled the top off the engine and discovered that the cam is wore just like I suspected. 

I am still not sure why it wears out?  In the first photo you can see the cam sitting in the "tin bathtub" full of oil.  It is definitely getting plenty of oil.  There was no noticeable wear on any of the other parts.

Here is the cam and followers removed from the engine.  You can see the follower on the right has a definite concave shape to the contact surface, it should be flat.  Both the intake and exhaust lobes were about .075" short.

I don't know why this is happening, but it seems to be a common problem on this engine.  An after market cam is available for about the same price as a new Honda original part.   I am going to recommend that to the owner.