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SWest wrote: putting in the pin I drilled for was very tight. I had to wiggle and twist it to raise it up so the bearing wouldn't move from side to side. The others were just as tight. It could be it is too low but I suspect it's sloppy in it's hole Licktight might help there but not on the bearing itself. I can see in your clip the race is moving about 1/8". I'd like to see the journals as well.
Steve

I'll split the case again and see what gives. At this point it looks like I'm gonna have to fix whatever the play is at the dowel, and tighten up and/or locktite the journals.

I suspect some red loctite on the pin will cure the problem. That race moves a lot. On mine you can see where the crank was wearing on the case. I could hear it chattering at idle. Another reason to tear down a good running bike. After all the frustration and work it was worth it. Now the crank is "Goot unt tight."
Steve

VTEC wrote: Hey Zed,

Hey, if you have an upper case and an outer race laying around please put it on the dowel and tell me what you see? Also, have you ever replaced a crank bearing dowel? Curious if they bottom out or have to be tapped in to a specific height?

Thanks...

The dowels are just a light interference fit and can be pulled out with pliers if you can get a good grip on them.
if one is much lower than the rest it's because the cases have been bolted up at some time with the bearing out of line punching the dowel in to the case.
If this is the case you probably won't be able to pull it out.
As long as they locate the bearing the height doesn't really matter but the lead into the bearing is tapered so that would allow the bearing to not sit in the correct position for end float control if the dowel is sitting too low .
The dowels protrude around 5 or 6mm .

I know I grabbed each dowel an jiggled to be sure they were tight, but it didn't enter my mind to check the height. This engine was previously built by someone who shouldn't. So nothing surprises me. Did I mention I removed a twisted/welded crank from this case?

OK. I split the case and pulled the crank. SWest was correct, all dowels are slightly loose in the upper case holes (possibly normal), but #5 is much more loose, and oblong in the direction of crank thrust. The height looks good, all about 5.6mm.

Wondering if the twisted crank was the root cause of all this.

Here's my plan at this point. 4 punch marks around each hole to tighten up and center the dowels. Then tap them in with Loctite 620 as Scirocco suggested. Then multiple punches on the main cap and lower half, with a coat of 620. Loctite only on the lower half to avoid the oil holes.

Any other suggestions would be greatly appreciated.

Here's a pic of #5 hole. Not sure if you can see the oblong.

If the crank was run twisted for quite a while it's possible that the increased vibration and out of true orientation of the crank pins have caused the bearings to work their housings slack and to loosen the pins..
The loose one at the end being where the crank was most out of tolerance.

I would do exactly as you suggest by staking the pins and then punching the housing with a smear of bearing fit to follow as insurance.

Yep. I guess that's the best way to go aside from a new case. I'll order the locktite, punch and cleanup the cases ASAP.

Zed. Let me run this one by you. I posted it a while back but never got a response.

Involves the trans countershaft, where 1st gear is separated from the RS needle bearing, and there are 2 thrust washers. All the manual states is that if the shaft doesn't turn when laid in the upper case, use the thinner one of select-fit washers. Same as the opposite side of the mainshaft.

On the mainshaft theres is maybe .005" clearance at the washers, but on the countershaft I have .025" with the thicker washer.

Check out this video and tell me what you think. Thanks.

www.realworldautomotive.com/kz-images/trans/trans.mp4

If you punch the journals, test fit the crank. You don't want binding on the crank or too much that can crack the case. I wouldn't punch both. I used a dab of silicon when I put the crank in to test. At that point I decided to file out the large punch marks. Peening around the pins should help. I was thinking a piece of steel tubing that fit around the pin would be better than punching around them. One punched circle.
Steve

I think I'm going to use more and smaller punch marks than showed on the video. Hopefully to keep the clamping force more uniform, and not too much. I also might plastigauge to see how loose we're talking about. It can't be much, no bearing spun and no marks on the journals.

Before i would do anything to the journals or pins, i would check the crank are in spec and not twisted !!!



Michael

Scirocco wrote: Before i would do anything to the journals or pins, i would check the crank are in spec and not twisted !!!

The previous crank was twisted and welded. Which I think confirms that somebody welded a twisted crank. Right?

This one was checked and welded at APE. They check for twist by running a 2 foot wrist pin through all the rods.

Ok thanks, I have missed this info.

SWest wrote: One punched circle around the pin

Maybe a tool for a punched circle.



In my opinion i would go the Loctite way and see what happend. I am not a friend of mechanical force on sensible engine parts .

Michael