different deck heights on rebuilt 83 yz250

split the cases, put new rod kit, crank bearings and seals in a 83 yz250. put the cases back together and then i noticed the cylinder deck heights are different from side to side. From what i can tell these cases had never been split before, and i put the dowel pins back in so they should be aligned. I can put a .008 gauge under a straight edge laid on the high side hanging over the low side. I am tempted to slap it together with plenty of gasket sealer and run it. Opinions please!!!

Did you put each dowel back into the slot you pulled it from?

You may be able to swap around the pins to get it lined back up

i didnt double check my dowel pin location?? i have never heard of this affecting case alignment? I think this could only be possible if the dowel pins had offsets in them or different diameters which i would have felt with my fingers as i put them back in the case.

If you are talking about 1 dowel going further into the case than the other, don't worry about it. When you bolt down the cylinder everything will set itself where it needs to go.

No, we are talking about the dowel pins shifting the horizontal plane of the deck surfaces. Bolting down the cylinder will not shift the cases square to each other.

I would take it to a machine shop and have the decks trued up

No, we are talking about the dowel pins shifting the horizontal plane of the deck surfaces.

... or maybe slop in the dowel pin holes allowing the cases to be fitted together out of alignment (pretty much the same thing).

I think I'd be more worried about possible shaft misalignments than the gasket surface, and would be more inclined to reposition the case halves than to machine them 'true' in a possibly misaligned state - but that's just me.

IF you used a non-hardening sealant and IF you were willing to try it, you could loosen the case halves, heat up the gasket and sealant real toasty, then use the cylinder to pull the case halves true - then retighten the case screws and check for leaks. I realize it's a non-ideal solution, but if it worked it would save you some time and effort, and if it didn't you'd be out maybe a half-hour of your time.


I get what the problem is now. Did you replace all the dowels and were they the correct part? I can see where too small of a dowel would let some misalignment happen. Can you post some pictures? Trying to run it will put your crank out of alignment and may eat up the bearings and for sure the main seals. Good luck.

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