I bought a head to replace one on my 1985 110. The head I bought is from an earlier year. The head part number is the same but the valve numbers are different. Will the 85 valves fit in the older head? Thanks.

 

ALL of the ATC90 and ATC110 engines use the same valves on both the intake and exhaust regardless of the year.

The only thing that comes to mind if you are comparing used heads and old valves are from the 125 engines.
They are different from the 90 and 110 heads.....and the valves are different as well.

 

Thank you very much Knowsalot. I was just thrown for a loop when the specs on Bikebandit.co had different valve numbers between the 84' 110 and the 85' 110. Also when I purchased the head off ebay they had "It is for a 1979 - 1984 ATC 110", which made me wonder whether it would fit an 85. So there should be no problem with placing the 84 or earlier head on an 85 machine? I probably just repeated my earlier question but i just don't want to tear into anything that wont work. Thanks again.

 

Well, it was probably listed for certain years because of the difference between the ignition covers. 79-81 used points and the 82-85 used a CDI system.
The small cover and base plate is different so if it was sold as an assembly, this would be the reason for designating the years.
The head will swap out. You just may have to use the ignition base plate and cover from your exisiting head.

 

Ok. Great, thats what I needed to know. I will just interchange the parts. Thank you.

 

Ya welcome. [img]i/expressions/face-icon-small-smile.gif[/img]