what motors will bolt into an atc 90 frame?

[chuckiedog04]

what motors will fit into an atc 90 frame? i have a 1976 90 im trying to fix up. just wondering what pit bike motors or other engines will bolt into it? thanks.

[Vealmonkey]

The only engines that will bolt in, are the atc90 and the atc110. Other engines will not fit without modification or other parts to bolt into place. Pit bike engines are based off the honda 50cc/ atc70 engine, which is smaller than the atc90/110. With enough modification, you can even make atc 200x engines fit into an atc90/110 frame. But that's really alot of modifications.

[muthey]

Veal what about a 125 motor, thought they were relatively the same as the 110 or do they only match up to the later model 110's?

[Vealmonkey]

I don't know this for a fact, but I don't think the 125 will work due to the electric starter.

[Jon Boy]

well, if you use the electrics and wiring to use the starter on the 125 you should be able to swap. 90/110/125 are basicly all the same really (not counting the 86-87's). starter shouldn't be an issue as far as mounting the motor.

[tblumer]

DrATV sells an adapter that should allow a modern chinese or genuine 50/70 based motor to drop in, although you'd have to devise a head mount for frame strength

[Louis Mielke]

Pretty sure the 125 engine will work, I think the electric starter is on the bottom of the engine.

[Jon Boy]

yeah, starter is on the bottom and you'd have to figure out where to put the other elec stuff for it. don't know if it will help you any really but here's a couple half-naked pics of my 125. :beer

rightside, starter is right under the cylinder and you can see how tight the carb and top valve cover are to the tank and frame.
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leftside, electricals are under the black cover on top of the frame above the muffler
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