here goes. It doesnt matter what the frame says,if you have a 6 bolt intake then your cylinder is an 88.The only diferences between 87 and 88 are: diferent piston,cylinder,cylinder head,reeds,reed boot.I have a 1988 motor in a 1987 frame as well. My 88 motor has an 87 head on it too. If you are running way to rich just take the jet you have to a shop like the guy above said,and go down 1 size at a time till its right.Then you can fine tune it with the needle clip,hope this helps.

 

Tolerance:: a new bore would have .003. up around .010 would be max IMO.