Carb backfire

[martin_t]

Hi

Went for a longish drive yesterday and while following a tractor at about 40mph I had a large (and quite alarming!) backfire which seemed to come from the engine bay (manifold?) but difficult to say. It certainly didn't seem to come out the back (I have a GD with underslung exhausts). I drove on for a mile until I found a lay-by and stopped to have a look. Everything seemed OK and the engine seemed to be running OK. I carried on and things seemed to run ok (all be it I was a little nervous!).
On the way home
I had a small muffled backfire out the back and once or twice a bit of "bogging" as I put my foot down. Then for the last twenty or thirty miles is ran fine. Engine sounds good, oil pressure is OK and water OK. Can anyone give me an idea what it could be or what I should be checking? The engine is an RV8 with a Holley 390 carb. My wife said "could it be dodgy petrol" as I had just put a tank full in. I said "nothing is ever that simple" but between you and me, could it be dodgy petrol?

I havn't had chance to check the plugs etc since then but have the evening free tonight to have a look.

Cheers

Martin

[topcatcustom]

What fuel pressure regulator are you using, and have you recently checked the timing? I had constant problems with a Holley fuel pressure regulator so will never use one again when Filter King make a much better product, and I also had backfires caused by not enough advance (albeit a blower engine).

[martin_t]

What fuel pressure regulator are you using, and have you recently checked the timing? I had constant problems with a Holley fuel pressure regulator so will never use one again when Filter King make a much better product, and I also had backfires caused by not enough advance (albeit a blower engine).

Hi

don't use a pressure regulator just a Carter fuel pump with an inbuilt regulator.

Cheers

Martin