Flaming Exhaust

Rode today and my 426 was poping on deacceleration. Well it got louder and louder. I came off the track and grabbed a handfull of throttle and when I let go with each pop flames came out of the exhaust.

A bit of background....

I got the 426 which had a stock header and an Arrow pipe. I managed to get hold of a ProCircuit setup, header and a couple of pipes from H4B. I ran the PC header and the shorter of the pipes for the last year. The PC setup gave more bottom end and better throttle response. A couple of weeks ago I was racing at Canada Heights and decided that I would run the longer pipe. Well I had it sound checked and it was registered at 102db. This pipe is quiter than the shorter pipe. It also gives less power at the bottom end.

Anyway I thought I would do my bit for the noise problems, so I put the stock header and Arrow pipe back on. This is alot quieter but unfortunately not as powerfull.

I used to run Optimax in the bike but recently I have run on normal pump gas. My son said his bikes runs better on Optimax so this weekend I switched back.

So the difference between this weekend and the last time I rode was the stock header, Arrow pipe and running Optimax.

What could cause these flames. It did look good though. Some kid said he wished his bike did that. I said I wished it didn't.

Sorry Gents, I pasted this from another forum in the uk. Optimax is premium pump gas from shell. Its rated at 97 Octane, standard pump gas is 95.

Decel popping is caused by either an air leak in the exhaust, probably the mid pipe joint, or lean idle mixture. Do a quick check of the exhaust system. If it's OK, back the fuel screw out a quarter to a half turn. No big problem in any case.

Bad gas

Found the problem. One of the bolts holding the header to the cylinder had fallen out.

Thanks for the help.....

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