Overfuelling/Backfiring

[Daimo]

Mornin all.

I've got an 06 Oil cooled 656cc Bandit S.  Shes now just clocked over 34,000 and has been used pretty much every work day for the last 4 years in any weather.  Shes been as good as gold really.

Recently when giving her a service, I noted that the 4-1 manifold was rusting at the link pipe section.  When I removed the rear can, the bracket fell apart hence meaning I had to weld the link pipe directly into the back of the manifold.  It seems i've had quite a hole and a lot of air leakage into the exhaust for quite a while.  All has been good since, ish..

Recently, I noted it was misfiring on very partial throttle, no power, then it would kick back into life.  It also started backfiring badly when cold, spitting ont 1ft flames when simply rolling (no throttle).   But when it was warm it wasn't so bad.  Some days it absolutly fine, but its now getting consistant and getting on my nerves.  I've not noticed any major drop in fuel economy.

When not moving, and you give it throttle, it is chucking out some black sooty smoke, but generally it still rides fine.

I've changed the plugs (originals were still in) and they didn't look too bad.  I gave the fuel filter a quick clean also.

But now im getting stuck.  I don't understand what would be causing it to backfire and pop and bang like it is (I still get power loss sometimes, and it only sounded like it was running on 2/3 cyclinders when under very very very partial throttle following a lorry).

Anyone got any ideas what my next steps in finding the problem would be?

Taaaaaa

[pmackie]

Hey Damio

Start with the simple things first...you may have already looked at these, but if not, start here first:

1. How's the air filter? Maybe try a new, clean OEM filter. The filter might look clean, but can also absorb moisture.
2. Check and inspect all your coil wires, high tension leads, and plug caps. A cracked or poorly connected plug cap can drive you nuts.
3. Remove and drain the tank c/w removing petcock. You want to make sure there is NO water in the system.
4. Once you have fresh fuel in the system, drain all the float bowls. Try to use gasoline that does NOT have any alcohol added.

Next step involves a little more work.
4. Remove the carb bank, and clean out all the carbs. When you reassemble, carefully inspect the carb to head manifold boots.

Let us know if these steps don't result in fixing the problem.

[Red01]

Also, check for any more exhaust leaks.