I sold this thing a long time ago, but whoever built this, jetted it to run correctly without the cap. And it's the exhaust the 90 rolled out of the factory with in 74, there's no spark arrestor.
Actually, someone has rejetted it way wrong the other way, it's stupidly rich, plug is totally black. And running a 4 stroke lean hurts the valves, not the piston.
Never got it operational to ride it, but I can tell you that it doesn't add near as much as the 90 swap did to begin with.
TrikeKid 2 years ago
put the spark arrestor back in, your engine will thank you. i only ride my xr70r with it off in my field, since i can really rip there.
MXHondas230 2 years ago
I sold this thing a long time ago, but whoever built this, jetted it to run correctly without the cap. And it's the exhaust the 90 rolled out of the factory with in 74, there's no spark arrestor.
TrikeKid 2 years ago
oh ok, cool. i think on a lot of ATCs theres a spark arrestor, but i guess not on this one.
MXHondas230 2 years ago
how much power does it add with the end cap off?
Codiva900 3 years ago
its the spark arrestor. it increases hp by about 2 maybe 1 and a half.
MXHondas230 2 years ago
nice 1983 atc 70. i have only seen one other one that is blue and it is mine.
jensenracing77 3 years ago
so that just has the cap tooken off the exsaust
ps. nice bike in the background :P
is that a kink?
rickjames400ex 4 years ago
Bike is a Volume.Exhaust has no end cap.
TrikeKid 4 years ago
Actually, someone has rejetted it way wrong the other way, it's stupidly rich, plug is totally black. And running a 4 stroke lean hurts the valves, not the piston.
TrikeKid 5 years ago
Put the end cap back on, you're leaning it out. Either that, or keep it off and rejet, or just stay lean and fuck your piston up.
400exXx 5 years ago
ok and
atvbad 5 years ago