Reliability problems with an 86 ATC250R motor in a TRX chassis

[TRX250Rider]

Hi,

I just recently bought an 86 ATC250R motor for my 86 TRX chassis. The motor is stock except for a fresh top end with a .010 over piston. I was wondering for anybody that has possibly done this swap before, are there any reliability issues with the ATC motor with a TRX chassis? The main differences I understand is that the TRX motor has a lower compression ratio (8.0-to-1 for the ATC compared to 7.5-to-1 for the TRX), less aggressive stock porting, 15% more radiator capacity, and 72 oil groove jolts on the clutch friction plates compared to 36 on the ATC motor. The reason for the changes was that the ATC engine tended to overheat in extreme summer conditions, like in the desert. I mostly ride in southeastern Kentucky, so the desert conditions don't really apply to me. However, I am worried about the more highly tuned motor and more engine failures. I am also worried about clutch failures. I still have the clutch from my old TRX motor, so I could possibly solve the problem by replacing the clutch system. If I do, what components would need to be replaced? I would sincerely appreciate anyone's help and would like to thank them for their time.

[quadracer87]

i wouldnt worry

[honda250r]

dont worry this swap has been done tons of times

[bean86]

Yeah i did it awhile back and have had no problems

[chiribomb]

I just did this with a 85 atc motor and I noticed that the carb boot and carb assembly are alittle shorter.

I just swapped my running atc motor so that I could test the 86 trx chassis that I bought with a motor that needs the top end redone.

The guy I bought it from fixed the leaking gas tank gasket with silicone, instead of a $1 oring, and it got into the petcock and carb so the thing would lean out and plug up.

I have a round slide carb that has been bored and had been running a 142 main with trinity stage 2 and an fmf pipe. Its been running great for 24 years and with just an upgraded clutch and 5 rebores over that time.

The trx motor had just a cleanup porting and 162 main with a 89 trx pt race pipe, k&n without lid.

I gonna try jet it for the this combo anyone have any suggestion should i just use the flatslide and jet it or the round slide and jet it.