Someone Please Confirm - 90CC & 110CC

[atctim]

I have done minimal research and have found that a ATC90's bore and stroke is 47mm x 41.4 mm and a ATC110 has a bore and stroke of 52mm X 49.5mm.

Am I correct in saying that the 90 head won't fit the 110 engine becasue the piston is different diameter, or will it still interchange.

Please, someone with more knowledge than me help me out.

Thanks,

ATC-Tim

[Howdy]

The heads on the 90 and 110's are the same. The later 110's had a CDI and the cams in them are different. But as far as the basic head they will work on each other machine.
Howdy

[greenhuman]

The first bore and stroke you stated is for an ATC 70. The standard bore on a 90 is 50mm. The 90/110 head will interchange.

[atctim]

OK - thanks for the replies. So is the 90cc and 110 cc piston diameter the same, just a differnt stroke?

Just want to know.

I'm happy to hear the 90 and 110 head are interchangable.

[qdmr666187]

i have a 1976 atc 90 and an 1980 atc 110 they are exactly the same transmission and everything but the 110 top end is bigger .