225dx/ timber wolf swap...help needed

[tony8008]

Ok, so long story short, I dropped the bottom end off a 93 timber wolf with the jug and head from my original 225 motor in the dx frame. I swapped the magneto and flywheel as well as the u-joint. Fired up and ran making a lot of clunking. Finally the starter just stopped engaging the gear. So I pulled the cover off and the flywheel had sheared the wood ruff key. Thought maybe it was just weak. I replaced it and put everything back together tonight and it lasted longer but did it again. Am I missing something for this swap? It seemed like it was pretty straight forward. Is there a trick to re-seating the flywheel? Any help is appreciated!

[tripledog]

Not familiar with Yamaha 3 and 4 wheelers, but I have an idea what of may be wrong. The clunking sound may be a result of a flywheel that is not fully seated. It would also explain the failure of the 2 woodruff keys. I would measure the distance from the keyway to the end of the threads on both engines' crankshafts to make sure they are the same, and take a look to compare the length and taper of the cranks' threaded ends. I would also compare both flywheels for differences such as the depth, diameter, and taper of the center hole. Just a shot in the dark...

[86125m]

Is your cam chain tight because I have had problems in the passed with a loose cam chain destroying two flywheels and almost destroying my case before I figured out it was the cam chain.

[350for350]

You will need to use the cam chain tensioner from the 225. I'm not sure why, but when I put a Timberwolf top end on a 225 bottom a few years back, I couldn't even tighten the 225 tensioner all the way up. For some reason, you need to use the right tensioner for the cylinder, not the bottom end.