Pumped

[james9r9r]

Ok I want to know how fast I could make my 1983 atc 70 engine go and big bore etc???

[ceaserthethird]

Depends How much Cash you got to invest ... Can Covert to a 2 stroke CR85 , Big Bore Kit's ...

Just do a search on - ATC 70 tons of info

[RedRider_AK]

[SYKO]

with a bigger carb and better exhaust I know for a fact my daughters trx 70 can do 40mph (had it clocked, by police freind) we couldnt beleive it!! she was flying! I opened up the intake tube to match the carb and all it has is a clamp on filter, im sure with a big bore kit it may go alittle bit faster, but it will get up to speed way faster

[james9r9r]

I wanna put a Lifan 125cc on there, then somehow bore it. How fast would it reach?

[SYKO]

well if you get one of the motorcycle 125 lifans I thing they can reach 55 or maybe alittle more, I really wouldnt want to go much faster then 30 on a little atc 70!! lol!! I save the high speed for soething bigger!! even though it would be fun to work on a good conversation peice!

[james9r9r]

I just want my 70 so it'll be loud and proud?

[Nightbiker07]

you must remember that more horsepower will not make it faster.......more RPM will.
after the motor has reached its redline of, say, 4000 RPM, it doesnt matter f it has 5 or 5000 horsepower, it will go the same speed (just accelerate harder)

you could get small speed gains out of more HP beczuse it will allow the motor to come closer to its redline under a load, but bah.

if your looking for top end, Mod the motor to get as much HP as possible, then gear the tranny with some taller gears.

[storm_impulse]

im not sure if this is as true to a vehical but with a bigger cam or cam grinds wont that bump up the rpm range? i noticed with a stock 200x my redline was about 55 to 56 mph, since i added a 1mm big bore kit and a performance web cam with a longer lift duration, and stiffer springs im hitting 61mph reved out. i was thinking about having a custom 5th gear made so i can atleast hit 67-68, maybe 70.