How to Check Crank Runout

[Ausm7499]

I am fairly new to the two stroke and snowmobile scene and was wondering how to go about checking the runout on my crank. I don't think it matters but the sled is an 08M1K.

 

[SPDFREEK]

Dial indicator

Leave your crank in your case half (make sure it is seated if the case halves are opened) and with a dial indicator touching your PTO side turn the crank (slowly)360 degrees and watch the dial indicator. It will move, they all do, but there is a tolerance of maybe .000 to .004 of an inch(not sure on the spec). Do the same on the mag side.

SPDFREEK

 

[WyoBoy1000]

can you check it on a sled with the motor still in it.

 

[MNF7]

Set the crank in a V block on the center bearings. This way you make sure each end is running true to the center bearing. I like to get each end within .0005 TIR. max.

MNF7

 

[ACMtnCat]

can you check it on a sled with the motor still in it.

Yes you can. Not as accurate as others.

Clamp/magnetic the guage to the frame or block and pull a plug out so the pull rope pulls easy and pull the rope slow and smooth.

 

[m_beeson]

Yes you can. Not as accurate as others.

Clamp/magnetic the guage to the frame or block and pull a plug out so the pull rope pulls easy and pull the rope slow and smooth.

Clamp your dial indicator to the block.


anywhere else will give you a false reading.

 

[Bearcat]

How do you straighten the crank if it's not good? Hammer like a fool or?