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Back fire

1101 Views 13 Replies 8 Participants Last post by Brad_G, 9 mo ago

Brandon wood

Discussion Starter · 12 mo ago

My 08 roadstar has cobra pipes. Before I put my baffles back in it was back firing and popping real bad. I put the baffles back in and it still back fires. I’ve already put new spark plugs in it and it still does it. It was a California bike with all the omissions on it. I’m 3rd owner and the charcoal canister has been removed by previous owner but the AIS lines are still on. Not real savvy on fuel injections. Does anyone have any ideas on how I get rid of the back firing?

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scootersage

· #2 · 12 mo ago (Edited)

I have a 08 looks just like yours. I also have Cobra long shots and a Baron big air intake. I removed the ais. I also have a Vance and Hines Fuelpak. It has a throttle setting to shut the fuel off and when it turns back on. No fuel no pop. I would take off the ais, you don't hear the popping with a stock exhaust. I don't get any popping on deceleration. Nice bike. I used the Baron AIS removal kit. Or you could just pull the plug on the ais and see how it acts. Ours are electric activated.

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Brandon wood

Discussion Starter · #3 · 12 mo ago

Nice I appreciate the info and I’ll try that. Nice looking bike

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random_guy

· #4 · 12 mo ago

The Warrior engine is similar so I'll chime in. Yes, remove the AIS. Then, if you still have backfiring issues, a fuel tuner will help a lot. There should be another option called a CO bump. Each cylinder is tuned separately. I'm not familiar with how to do it on the Road Star but the Warrior requires "shorting" out wire 29 from the ECU to ground (there's a precise procedure, don't risk doing it without the procedure or you'll fry your ECU) and then some button pushing on the dash. This is common on the Warrior to help tune the fuel map in the ECU for when the throttle is closed. This will help to eliminate the backfiring during deceleration.

Hope this helps.

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Brandon wood

Discussion Starter · #5 · 12 mo ago

I appreciate that. I was not aware of that procedure but I’ll look into it thanks.

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Deeksvstarclassic

· #6 · 12 mo ago

Brandon wood said:
Nice I appreciate the info and I’ll try that. Nice looking bike

Yours looks pretty sweet as well would love to see more pics of it

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kje54

· #7 · 12 mo ago

My 950 has aftermarket exhaust and pops a bit on deceleration. Doesn't bother me so I haven't worried about it.

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SmittySmithsonite

· #8 · 11 mo ago

These 3 most common things will cause excessive, loud backfiring:

Too rich air / fuel mixture
Too lean
Air leaks at the exhaust manifold gasket where it meets the head

This can also be caused by ignition problems, or valve, or valve timing issues.

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Brandon wood

Discussion Starter · #9 · 11 mo ago

SmittySmithsonite said:
These 3 most common things will cause excessive, loud backfiring:

Too rich air / fuel mixture

Too lean

Air leaks at the exhaust manifold gasket where it meets the head

This can also be caused by ignition problems, or valve, or valve timing issues.

I appreciate the info. I’m going to check those out thanks