110 case issues

[elitespecialkid]

Hello all,
i have an 81 110 ive been trying to rebuild, bought a big bore piston, high lift cam and larger carb. after putting the whole top end, together, i realized that a broken chain from one of the previous owners had cracked the case. ever since, i have pulled apart an older 90cc engine, which had a different case, and now i just pulled apart an 80 110 engine, and the cases look similar, but just slightly different. does anyone know if i can use the different case? will it mess with oil passages? as far as i can tell, any bolt holes look to be in the same place.
Thanks for the advice,
Elite

[elitespecialkid]

i should mention its an ATC, just for clarity

[90guy]

Dont quote me on this. But I do not think that the 90 case would work with out milling it some to match the other side to fit the little longer stroke of the crankshaft.

[YTZ drew]

I rebuilt an old S90 (funky 1960's street bike) about 2 years ago, using an assortment of ct90, ct110, and atc110 parts. I can tell you that CT110's have atc125 style cases and heads (2 bolts on the jug near the timing chain instead of 1), but ATC110's have ct90 style jugs and cases. I was able to use atc110 cases with 90 parts, but the cylinder studs were different lengths. The ignition side cover was where the biggest trouble was. There's an oil gallery in the ignition side cover that was different between the atc110 case and the ct110 cover I used (125-style engine). This caused a HUGE oil leak until I welded the cover to add materiel over a part of the gallery that was machined into the left half of the engine case.

As long as the top end seems to bolt up, you're good, just double check that oil gallery if using different cases. The shape is different enough to see with the naked eye, and if you must mix/match parts that don't jive, some welding and grinding will take care of it.

[elitespecialkid]

i appreciate the replys. I think what im gonna do is pull this 110 case off that looks incredibly similar. make sure the head studs are the same length (top end looked exactly the same) and make sure all the oil passages look the same, bolt holes, etc. the only difference i have noticed so far on the 80 110 case has the shaft for the neutral indicator seperated from the rest of the timing chain case. the 81 110 case does not have this divider.

[C.J]

The points 90/110 cases are the same, the 90's just had a shorter stroke. I'm not 100% sure if a 110 crank fits in the 90 case with no mods.

But so long as you have two points cases or two CDI cases, you're good to go.

Or just swap the top end to a good bottom end.


92 JP Outlaw hybrid (in progress)

87 LT265R (not much left stock)

[elitespecialkid]

Im planning on trying to use the 80 110 case and putting it one the rest of the 81 110 bottom end. Ive been helping a friend try to get his pick up running since his car blew up, and this has been on the back burner the last few days. hoping to do it soon though. ill post my findings