85 250r question

[rippn250R]

i have a stock 85 250r and i bought a 1987 trx 250r carb for it. Since my wheeler is stock i thought i would get the stock trx jets for the 87 carb and see how it ran since my 85 is stock also.I fired it up and it idled good but when i get on it it it breaks up. I know its probably the jets. Can you use an 87 carb on an 85? If i can what size jets should i run?

[86250RZ]

Just check the jet sizes in your 85 carb and use the same in your newer carb. The (86up) carb W/ flat side slide will work much better than the old (85) round slide carb. (86 up) carb will run smoother and give you a crisper throttle response.

[rippn250R]

if i put the same jets from the 85 carb in the 87 wouldnt it run leaner because the carbs and jet sizes are totally different.