Gs850 Backpressure

[gs850bobber]

Hey everyone got a simple question. I have a 81 gs850G that i recently turned into a bobber, in the process i cut off the megaphone stock exaust 3-4" back of the rider foot pegs, and subsquently have no back pressure. So now it back fires only when i let of the throttle, my question is, is there any way to build enough backpressure so i dont burn up the valves and gain low end torque and or reduce the amout the engine backfires. Thanks

gs Bobber

[49er]

Hey everyone got a simple question. I have a 81 gs850G that i recently turned into a bobber, in the process i cut off the megaphone stock exaust 3-4" back of the rider foot pegs, and subsquently have no back pressure. So now it back fires only when i let of the throttle, my question is, is there any way to build enough backpressure so i dont burn up the valves and gain low end torque and or reduce the amout the engine backfires. Thanks

gs Bobber

Yes, you could fabricate cones that restrict the outlet flows significantly, or refit the original pipes. Why did you hack the original setup? For more noise, or appearance? Your engine will be running a lot leaner than previously.

[jabberjoe87]

put the exhaust tip in it, drill a hole for the screw to go in. I am curious as to why you cut the megaphone as well

[bwringer]

You've already been given good advice on where to start with rejetting and on inserting a baffle over on the tech forum. Are you expecting a different answer here?

[trippivot]

You are NOT going to "burn" a valve with un corked exhaust pipes. or from backfiring.. quick cooling may bend them but NOT likely. where did that myth come from?

weld a washer inside the pipes. or crimp the end to 0.85 of original pipe diameter. that is a performance exhaust flow ratio for exhaust gas velocity.

and the back fires will still be there until you get a diffusing cone and a reverse sonic baffle.

some times boosting the pilot carb circuit a little richer will help on de - acceleration.

Hey everyone got a simple question. I have a 81 gs850G that i recently turned into a bobber, in the process i cut off the megaphone stock exaust 3-4" back of the rider foot pegs, and subsquently have no back pressure. So now it back fires only when i let of the throttle, my question is, is there any way to build enough backpressure so i dont burn up the valves and gain low end torque and or reduce the amout the engine backfires. Thanks

gs Bobber