Hi All,
It's only a minor irritation at first. When I turn my kit off, about 2 secs later there is a massive backfire, sounds like a gun going off and
enough to set off my tintop car alarm.
At first i thought not too bad. But going to a petrol station or coming home late is rther embarassing.
Whats the cause and is there anyway I can stop it?
what engine is it mate?
quote:
Originally posted by jpindy3
what engine is it mate?
any chance the exhuast could be blocked?
quote:
Originally posted by Mark G
any chance the exhuast could be blocked?
check all air ways,in and out,take cam cover off and have a look at the rods ect.im no expert on xflows
Backfire from exhaust I presume - I did have one from a carb at one stage...
Wikipedia is your friend...
http://en.wikipedia.org/wiki/Back-fire
I'd say basically has to be excess fuel / poor timing...
How well set up are the webbers? Does the exhaust pop and crackle on overrun?
JC
i'm not expert, but i'd doubt it being the timing being out if it does it 2 secs after the engines switched off.
air leak in the exhaust maybe? allowing extra oxygen in to get amongst the unburnt fuel in the hot exhaust (from the few turns of the engine it makes
after it turned off, as it would still suck fuel from the carbs)
quote:
Originally posted by blakep82
i'm not expert, but i'd doubt it being the timing being out if it does it 2 secs after the engines switched off.
air leak in the exhaust maybe? allowing extra oxygen in to get amongst the unburnt fuel in the hot exhaust (from the few turns of the engine it makes after it turned off, as it would still suck fuel from the carbs)
I've had the same set up as you for the last 7 or 8 years, similar issues too, based on your recent posts.
For a popping and backfiring exhaust I would always look for an air leak first.(especially if it was OK previously and nothing else has changed).
integrity of exhaust manifold gaskets seal - you might see soot or feel gas escaping.
tightness of exhaust manifold nuts, go round and tweak them up
tightness of any joints in pipes or silencer - how are they joined? Slotted and clamped? very difficult to seal.
look for any cracks especially at welds and rigid connection points
Look for incomplete welds too, the 4-1 collector might have been tricky to weld (mine was)
D
excellant suggestions, I found a leak on the box, little bit of paste and problem solved.
many thanks
I'm off to do the same then!
Started to tell people it was because it was soooo highly tuned!!
mine used to do that too, i loved it! 
quote:
Originally posted by JoelP
mine used to do that too, i loved it!