Or a little less-pretty sure some of those pistons are around 74mm. If it were me (yeah, I like to do things the cheap and practical way), I'd round up a decent '80 CR250R cylinder and have it sleeved or bored and replated to the biggest you can go.I'd bet you could take it out close to 76mm like the 300cc ATC kit had and use a Kawasaki watercraft piston (there's a place who makes it all work for a 3-wheeler crowd-Google 300cc Hondaline kit ATC and you can find it). And with a 360 cylinder, your pipe will be very compromised where it exits the frame due to the exhaust port differences. You get into volumetric efficiency and such. That's just way to big a bore for the same 250cc sized stroke. Powerwise they were kind of a disappointment (I'm sure some guys with ME360 CR250Rs will argue) as they had a bit more grunt than a regular 250 but were not anywhere near the 400s they had to compete against. The 360 kit sounds cool, but it's just a very large big bore kit in reality. To be honest, it would be a lot of trouble for not that much gain. Maybe someone else typed up some instructions.
He says the kit has instructions on how to make it fit the ATC.I find that odd as the kits preceded ATCs by a few years. He apparently has a Mugen 360 kit for CRs (he states so and if you read the reponse to the first question at the bottom he reaffirms it). I'd think for over 2 grand he could have posted pics.LOL. the '80 CR and all ATCs with the senter port. There would be and issue with the ezhaust port, though-the 360 kits were made for '78-'79 CRs with a side-exit exhaust vs. Not to say some ATC guy didn't go to the trouble to put a 360 kit on and ATC (with the requisite stud relocation, etc.), or even just mount a 360 kitted CR motor in an ATC. The ATCs got the 300cc kit that sold through Hondaline. I've never seen a Mugen 360 kit specifically made for ATCs and I would have thought I'd have heard of or run across one or two by now. So does a 1981 ATC250 Mugen ME360 kit not fit a 1980 CR250 bottom end? As from what you say the stud pattern is different?įrom what I recall, the Mugen ME360 kits are CR-specific and were never made for the ATCs. It is kind of tough to find '80 CR stuff (I well know.believe me), but in the long run easier to turn up the motor you need and do whatever is needed to fix it that try to shoehorn an ATC motor in. Again, kinda-sorta based on the CR motor, but a lot changed for the ATC. As for the motors.again, most assume they are the same or nearly the same. If it was an easy swap, I have a few Hondaline 300cc top ends that sure would be nice on CRs.but they are more fun on an ATC. and '80 CR250Rs, as well as some '81-'84 ATC250Rs (they are sooo much fun), and grew up messing with both and have nued doing so up til now. Just find an '80 cylinder and sleeve or replate it if you must. I know if a few guys who spent beaucoup bucks to put a CR topends on their ATC lowends, but there is no justification to go the other way.
the CR's chrome plated bore, but the mounting stud pattern is off just enough to make you really have to want to spend time and money to make it work. The cylinders look the same, have the same basic design, etc.
Well, not without spending tons of money to make no gain powerwise (ATCs have milder porting).
I'm pretty sure that ATC 250R DG heads have been mounted on 78-80 Elsinore's.I do not know how they differ,but the head bolt pattern is said to be the same.I have also been told that chupacabra hunts chivos in this part of the world.Trust but verify.Ģ50R engines have been transplanted into old Elsinore's,but you have to hack the shit out of the front of the frame to make room for the counterbalancer.They look real ugly with the frame mods and that big bottom end in my opinion.A good tight 250R is a handfull.I was more impressed with the power of the 250R's than the 78-80 Elsie's.That counterweight must do something in there.Try asking the trike guys on one of their forums.This question has been asked many times.I would like to know the answer myself for the sake of curiosity. The bottom ends are way off.The 250R has a counter weight in front of the crankshaft that helps the Elsinore based power plant move more pork.It will likely be different around the area of the kicker gears also. Posted: Sat 12:14 pm Post subject: Are 1981 ATC 250R and 1980 CR250 enigines the same?Īre these engines the same? Are the top ends interchangeable? Swapmeet Discussion Board :: View topic - Are 1981 ATC 250R and 1980 CR250 enigines the same?Īre 1981 ATC 250R and 1980 CR250 enigines the same?