4k - backfiring HELP

1goodidea · Post by **1goodidea** » Thu May 19, 2005 1:05 pm

Well it's more of a constand pop pop pop pop pop whenever your not accelerating except for at idle.

Not just when you decelerating say when comming up to a giveway but even changing up/down gears.

What could it be? I have gaped plugs,and points got new rotor and dizzy cap, adjusted timing, set idle, adjusted air/fuel mixture as best i can all seems fine.

any ideas?

Standard exhaust

pervert · Post by **pervert** » Thu May 19, 2005 1:06 pm

An exhaust leak could cause that...

1goodidea · Post by **1goodidea** » Thu May 19, 2005 1:11 pm

oh k, it has a leak but i can't see how it could affect it.

It's right at the end of the rear muffler where the muffler meets the exit pipe! it's been like that for about 5 months tho, not prior problems

pervert · Post by **pervert** » Thu May 19, 2005 1:32 pm

Hmmm, I doubt a leak there would cause it, it would usually have to be a lot further up around the flange/flexi sort of area.

Mine makes the same noise when not accelerating, but thats because of the exhaust on it, it didn't use to do it with the standard system.

LEV_101 · Post by **LEV_101** » Thu May 19, 2005 11:28 pm

could your spark plug leads be a problem. how old are they?

1goodidea · Post by **1goodidea** » Fri May 20, 2005 8:05 am

yeh they are pretty old, going to replace them next.

I don't think they are the problem though as it seems to be getting perfect spark

scope · Post by **scope** » Mon May 23, 2005 10:46 am

when my ke30 had a 3k in it it did this backfiring and even the 4k does it. as pervert said it might be cause of non-standard exhausts though?

TygerTung · Post by **TygerTung** » Mon May 23, 2005 10:50 am

It's all part of K series syndrome

pervert · Post by **pervert** » Mon May 23, 2005 10:51 am

Yeah, when I had the standard exhaust (with a hole in the mid section) it made the same noises, then when I went to a free flow with extractors it got even worse, but it now sounds pretty cool, rather than tinny.

When I put the new carb on it quietened it down heaps.

Muzzie · Post by **Muzzie** » Mon May 23, 2005 11:04 am

Exhaust probably.

I have a straight pipe off the manifold of mine and it backfires and burps flames all day long, never did with the original.