Wristpin Problems

jad0001 · Sep 26, 2015

I purchased an '06 YFZ450SE that had been blown up and had the bottom end rebuilt, new cylinder and top end kit; just needed to be put back together.

The top end kit (Prox) was missing the wrist pin and circlips so I ordered OEM. The wristpin fit the piston but the circlips were too big so called Prox and got the correct circlips.

I went to install the piston just now and the wristpin is too large for the rod (Hotrods). It fits the piston perfectly but too large in diameter for the rod. I'm at a loss now.

I'm guessing I'll need a whole new piston kit but I don't know which size wristpin to fit the Hotrods crank.

Anyone have a suggestion? Thanks for any advice

buckwild · Sep 27, 2015

20mm is OEM,WR cranks use 18mm

diypunx · Sep 27, 2015

I think you got that backwards, 20mm is OEM wrist pin size and the WR crank uses the smaller 18mm wrist pins.

buckwild · Sep 27, 2015

Brandon your correct,sorry it's OEM is 20mm wrist pin and WR is 18mm wrist pin(fixed previous post)

jad0001 · Sep 28, 2015

Thanks, so what top end kit will work with the 18mm wrist pin?

Or should I say what is the best to use?

I like to stay OEM but don't imagine I'll be splitting the cases to fix this problem. Still curious as to why the PO used a WR crank.

buckwild · Sep 28, 2015

WR crank has more "meat" around the wrist pin area,and tends to rev a little quicker and it's a direct replacement over OEM,as for top end kit I would use Cometic gaskets

jad0001 · Sep 28, 2015

Thanks, what confuses me more is the PO used the WR crank but he purchased a top end kit with a 20mm pin.

I found a Wiseco piston kit for a YZ450 with 18mm pin. After realizing what rod I had I read I could use 03-06 YZ or WR pistons.

Thanks again for the help.

Wristpin Problems

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