Author Topic: Flame Thrower (Read 2259 times)

Dom · « **on:** October 11, 2006, 10:48:20 AM »

Ok, this cant be right...
My 500 has recently started to backfire quite a bit when coming off revs, in all gears and even in neutral. After a long 350 mile drive this weekend it appears to be worse, backfiring both from the carb and the exhaust at even lower revs than before. It wasn't until today, when a friend was driving behind me, that it became apparent that on some of the back-fire (explosions!) a flame shoots out of the exhaust and sometimes some short spats of black smoke also.

I am pretty sure this is not good, but how much damage is this causing the little engine and what could it be? I am wondering if it may be a result of some over tuning? I have been told that it could be the timing being out? If so, how can I correct this?

The engine is a 126 - 652cc, with a fast road camshaft, Dell'orto FZD 28/32 carb, sports clutch, alloy sump and sports exhaust.

Any help, much appreciated.

Dom

darrel · « **Reply #1 on:** October 11, 2006, 10:54:40 AM »

yep timing is out. You need to but a gun on it to get it lined up again. I would of said it was too far advanced, but you would certainly need to check it before retarding it.

Pete126 · « **Reply #2 on:** October 11, 2006, 11:44:22 AM »

Hi Dom, check the points first they may have closed up, check the condenser, and then check the ignition timing, 126dave has a similar set up to you, and he maybe able to help on the ignition setting

126dave · « **Reply #3 on:** October 16, 2006, 06:09:24 PM »

hi,id go for the points,if your timing was good before the only thing that can change it would be points closing up,or dizzy loose,doubt that though.

also check your exhaust and carb mount for leaks,when my soft mounts started breaking up i did have some back fires thro the carb....... :

:

cannot help you with timing marks,mine is done by ear and road test.
but if in doubt use the book marks as a start :cool:
good luck