crank life

[quads98]

how many hours can i expect from my crank i have a baldwin motor sport 265 powervalve on top all bearings were replaced 50 hours ago gas oil ratio 32 to 1

[Aceman]

Couple years on a raced motor? Probably much longer for the casual trail rider. I just rebuilt my bottom end, the cases hadn't even been split before and mines an 86. I could of even waited a few more months probably but decided not to chance my new motor.

[SuperChris]

What's your compression ratio? I put new bearings in my Race motor's bottom end every hour and a half or so, but I run somewhere around 300 PSI. I have tried three different gages and they all pegged themselves at 300. I have run 220 psi on my rec. motor for as long as I can remember and the bearings are still good.

[86 Quad R]

alot has to do with the compression ratio you run. i've always ran about 185 in mine and punish it hard on the creeks and sand bars/pits in my area. the last time i freshened it up it had about 4 years on it. prior to that it hand about the same time on it. as it was a fresh OEM atc crate engine when i originally purchased the quad 9 years ago.

i reccomend that an inspection be done ever so often to check the bearings in the counter balancer and while in there inspect the crank bears for slack aswell.

for better insurance i run(aswell as many others) run the cr500 bearing which has an extra ball and is a bit tuffer than the oem R bearing.

[guggi102]

The bearing I was told is from a cr250 but either way the moose bottom end kit for 50 bucks is the same bearings with seals for less then just 2 OEM bearings..

[86 Quad R]

as long as they're of OEM quality.... thats cool. :)

[C-LEIGH RACING]

Lets not forget the type of air filter used or how good its cleaned each time & the size of jets suppling fuel through the engine.
I beleave the biggest wear point in a crank is the small end where over time you end up with an elongated hole & then a knock.
Just think about how many times the small end stops & then starts back moving with each rotation.
Neil