Someone who knows, tell me what I do

[1sttimeXSowner]

I need some help from you knowledgeable folks who know about this stuff---I changed out the mufflers on my 82 XJ11 and slipped on a set of screaming eagle turnouts off a Harley Sportster--did not change out the headers or alter anything else except to bolt on the pipes to the frame. But now the bike backfires and there's very little power in the low rpms under 2500--I don't understand the dynamics enough to know how this would affect things but what do i need to do to correct it? Thanks

[brcree]

pipes

Hay first time.........most of the time when pipes a swapped out you need to rejet your carbs. Your blowen out more exhaust than stock pipes did most of the time. If your new pipes have no baffling you have no back pressure for the valves to work properly. Either rejet....or baffle if needed. Hope this helps.

[Ivan]

The stock exhaust on these bikes is pretty finely tuned to the engine, and is actually pretty desirable to have. Putting on low backpressure mufflers is going to give you a dead spot on the low end that just won't go away. I had a 4-1 with a cherry bomb muffler on it and I could get the dead spot minimised, but it never went away. Tried all kinds of jetting, adjusted the slide springs, tweaked the needle height and nothing worked. Then I bought a set of Jardines and the dead spot went away. I lost a bit of top end pulling power, but all in all it was a great improvement in drivability.

So, your easiest option is to go back to the stock pipes.

[crazy steve]

Trade those SE mufflers to a Sportster guy for his unmodified stockers (do check that they haven't drilled/bashed the baffles out); that will most likely cure the problem.

'78E original owner

[mro]

Cheep fix?

weld a washer to the head on a 1/4-20 bolt.
Drill hole in the bottom of the pipes after they come together and install the washer bolt goodies. Double nut em so it won't come loose. You can now turn the bolts which will change the angle of the washers in the exhaust to increase or decrease the back pressure.

Special Ed (Liberty) used to have a set of turn outs on his XS and seemed to be able to keep up just fine although was a little on the loud side. Don’t know what he did to tune his bike for em.

mro