YZ50 engine rebuild - PROBLEM

[monaro308]

Is there a gasket in between the cases or just 3bond,hard to tell in the pics.

Just threebond.

I'm not familiar with YZ cases...does that mean the YZ's ran no gasket in between the cases?
That might be the clearance you need.

[Hoony]

yes spot on monaro, this is the case with some yamaha's.

[YZ250H]

OK, she's back together again and the crank turns freely.  I tried a combination of things you guys suggested.  At the end of the day I don't think either bearing was pressed into the crankcase enough.  A little heating in the oven a bit of gentle persuasion with the dead blow and tongue in the right position and it all seems to be good now.  I don't think it is dragging at all now as it turns quiet freely.  I didn't buggerise around with the crank as I measured it properly with a dial guage and it seemed to be OK.

BUT.. now the shaft that the clutch basket bolts to (main) has about 1.5mm of end float.  Is this right.  The gearbox diagram on the Yammy website doesn't show any washers or spacers between the last gear and the LHS crank case, so I assume it's all good.  I would hate to get the whole thing back together and have to start again  .

[wmc83]

My 125j had quite a lot of end float and you could move the primary drive around a fair bit. The clutch plates and presure plate seemed to tie it all together once it was assembled if thats any help

[DR]

so long as it selects all gears and feels nice and positive then the endfloat is acceptable it is common

[YZ250H]

Sweet, thanks guys.  I will continue to put her back together 

Thanks for the help everyone.  I will post photos when I get a bit further along