1998 cr125 front motor mount bolt size??

[Greg Narvas]

I have a stock 98 cr125 motor with a steel psr motor mount. The motor mount uses m10 bolts. These bolts do not fit through the front mounting location of the case. From reading older posts, it seems that in 99 they used the larger m10 bolt rather than the m8 bolt from 1998 and older motors. I've read that I should use a 7/16 dill bit to drill the case out but 7/16 is closer to being 11.11mm. Is that too much slop for an m10 bolt or is that ok? I've read of people on here using a 3/8" drill bit with 3/8 bolt but I would feel better using the supplied m10 bolt.

Second, I just rebuilt my motor so it's fully assembled. Is it ok to drill with a good quality hand drill or would it be wise to do it while the cases are separated?

[Chris Reinhardt]

The PSR mount came either with a 5/16" bolt prior to the 99 motor's or 3/8" after the 99 motors, they never used a 10mm bolt that I knew of. Somebody might have drilled the mount for a 10mm if it has one.

You can drill the early cases out to 3/8", it's a little easier if the cases are dissembled, but you can do it after as well. Drill from either side, should be ok...

If it's a 10mm bolt, I would not drill it to 7/16", 13/32's is closer, or buy a 10mm bit.

CR
_________________
East Coast Super Kart Series
"This is how we roll!"
www.eastcoastsuperkart.webs.com

CR2 Motorsports
"Home of Cobalt Superkarts"
www.CR2MotorSports.webs.com

[Greg Lindahl]

From experience, use the correct bit size (10mm, etc.) and drill slowly and carefully for best results.

[Greg Narvas]

I ended up following CR's advice. I didn't realize that that PSR front mount bolt was actually 3/8". So I ended up getting a 3/8" drill bit and slowly drilled out the front case and everything fits nice and snug. Thanks again!

[Chris Reinhardt]

Measure twice, drill once

CR
_________________
East Coast Super Kart Series
"This is how we roll!"
www.eastcoastsuperkart.webs.com

CR2 Motorsports
"Home of Cobalt Superkarts"
www.CR2MotorSports.webs.com