Exhaust Popping and Flames (help)

Hey guys... I have an 82 xj1100 with stage III jet kit, shorty 4-2 exhaust, and pods with velocity stacks....

I had my bike tunes the other week, and got it running smooth, and niether of the exhausts were popping. I took it on a few rides, on street and freeway, and everything was still great.

Last night, my friend asked me if he can ride it up the street, so I let him. He rode it really hard... much harder than I ever would... it sounded like he was squeezing the throttle the whole way and just not letting off, while going up the gears (he was shifting). Now the right side exhaust makes a popping sound while shooting flames when ever I let off the throttle when on the road, and when I gun it in neutral.

Does it need re-tuning or does that sound like something more serious?
I've only heard it pop like that when it wasn't tuned! But how does running it hard affect the tunning?!

Thanks

 

to get fire out the exhaust you've got to get fuel into it. Unless your exhaust is VERY short. It's possible you got a float sticking and leaking fuel into the intake. Or a cylinder no longer sparking and dumping the fuel into the exhaust.

 

Do yourself a BIG Favor, ...

Pull the Spark Plugs and line them up 1, 2, 3, 4
Take a Picture of the Business ends.

Close-up, focus and good light!

Let's see them Plugs before you Rocket into oblivion.

Clean: Dangerous
Yellow: Also dangerous.
Lt. Brn: Lean. Fast burn. Performance tune.
Brown: Normal.
Dk. Brn: I doubt they'll be Dk. Brown.

 

Hopefully it’s something as easy as a stuck float. Always check the simple/easy stuff first.

But...(Not trying to scare you)

If the Cam chain tensioner was loose (not sure if the XJ1100 is an auto tensioner) it could have slipped with hard acceleration and hard deceleration and allowed the chain to jump a tooth.

If it is not a auto adjusting tensioner, you could look into getting one from a Venture of VMax they are a bolt-on swap (Once you fix your problem)


When I got My XS1100 (same engine as the XJ1100) the tensioner bolt was strip and it jumper a couple of teeth and bent a valve (OK three valves) Easy to check timing. Do a compression check (if valves are bent it probably wouldn't run)

 

Let's start with a compression test.

This is a pod-equipped, rejetted bike with relatively open exhausts, that was repeatedly redlined or possibly over-revved.

It could have burnt a valve or holed a piston or jumped cam timing (doubtful since it runs) or shook something loose in one of the carbs. Hopefully the latter. A compression test will immediately tell us if there is any internal damage; if not, then have at the carbs.