im doin a 95 kit and was wondering at what point it becomes a good idea to have the crank trued and welded

 

it depends -- some do it on 103/107's I have had two 107s and a 103 no crank or motor problems--this was a big issue on the 07 models but it did not materialize like the forum would let you to believe.

Anything above 125 torque would probably benefit from having the crank welded and timkin bearing, especially if you are doing rolling burnouts/wheelies/etc.

 

ive heard the most 95 builds are OK with how they came off the showroom.

Unless there is a for sure run out problem, id just run it as is.

if you got into all that with the 4.00 stroke crank, id bore the cases and make a big bore 107.

 

If going beyond 107" I always recommend having the crank worked. For 95-107 builds, it is not a bad idea but there are thousands out there running without crank isues. When you do your build, measure runout. If beyond .003 do not use gear drive cams, if beyond.005 I would have it trued and pinned/welded. I have measured three 2010's from the factory at .045 and greater. You can get away with greater runout on stock or slightly modified engines, but that doesn't make it right.

 

In a high out-put application, with an aggressive rider, I'd say a good idea, but usually not needed in the 100/100 builds.
But on the flip side of that, an ounce of prevention...etc.
Scott

 

If you split the cases.

Always do as much as you can when doing this.

 

We have seen a few of these cranks with run out issues, a few with rod clearance issues, and a few with bad rods. We like to inspect these cranks for rods being out of round on the big end (pinch), damaged, and thrustwasher wear and always plug and weld them going back together.