Crank end play

[CDBiker220]

Hi, been having issues with a inconsistant idle on my bike (07 EC300) as well as some pinging under abuse even though jetting should be pretty rich. Decided to check crank seal, looked fine but am replacing it anyway. My crank has no play up and down, however it will move in and out (of the case) about 1/16 inch, maybe a little less. I am wondering if this is normal...i did some research and found this could be an issue with older models with different bearing type. Is this normal on an 07 though? Bearing doesnt sound loud or anything, no unusual vibration.

[stainlesscycle]

Originally Posted by CDBiker220

as well as some pinging under abuse

check your ignition timing. ping under full load/wot is usually timing.

[CDBiker220]

Not as much worried about the pinging right now as the crank. Does anyone know if the in and out of the ignition side play is normal?

[PEB]

I just checked my 07 no movement side to side. I am a hack mechainc but I can't see where there would be room for slop in the crank side to side. Seems like it would mean there is play in both sides of the crank. Hopefully someone else will chime in.

[Neil E.]

What is in the engine for bearings? The older manuals show ball on one side, roller on the other. You usually only feel end play when the crank has roller bearings on both sides.

A ball bearing is normally mounted with a slight interference fit, so you won't feel any end play because the ball bearing is holding the crank in place.

If you have enough shaft to bearing wear that you can feel end play, I think .005" to .010" end play would be OK. This is measured with a dial indicator. Lots of end play won't stop it from running, but your crank seals might not last as long as they should.

With either type of bearing you need accurate dimensions for total width so the crank won't be pinched when the cases are assembled.

[GMP]

You likely have a loose fit of the right side crank journal in the right side main bearing. The crank can slide in the bearing and move side to side slightly (axial play) The ignition side roller bearing is two piece and will not prevent movement. If your changing the ignition side seal, you can do the primary side as well and check the bearing for radial play.

If all else is good I wouldn't worry about it for now. As long as it doesn't have an increase in vibration just ride it. When you tear it down for a rebuild you can have the crank metal sprayed/remachined for a tighter fit, or replace the crank from a part out if available. I did this to an older 250 and 125, the 250 ran for two years first and the 125 for six years.

Oh, its normal for the ignition side roller main bearing to have a barely detectable radial play.

[CDBiker220]

After removing the ignition side seal I can see the roller bearing. I will be replacing that seal. I will look into the clutch side next. Ignition side has no radial play except when the piston is tdc or all the way down, then it is barely noticeable, feels normal. I will try to measure the axial play. Just bought the bike and really dont wanna tear it down to do crank work...

[GMP]

Don't worry about it, if it runs good with no vibes just ride it. Mine went a lot of hours and could have gone more.

[CDBiker220]

Just checked the endplay, only had calipers to get a rough measurement. Looks to be about .017" to .022" of play. I plan to atleast take off the clutch side to inspect that seal and bearing. I assume I can get to it?

[PEB]

You can trust GMP's advice, he always has rock solid info. Yes you can get to the clutch side seal without splitting the cases, but you have to dig for awhile to get at it.