Baffling carb problem

[gtr-gaz]

I have a Demon carb fitted (or rather I did!)

The Demon was perfectly set up originally. The engine ran well, no hiccups or stalling at all. It now runs like a pig. It kangaroos like you would'nt believe at almost all engine speeds. The only time it behaves normally, is when the accelerator pedal is nailed!

I know it's the carb, because when I put the old Holley back on, it does'nt do it.

I bought a carb repair kit (all Holley parts fit the Demon) fitted a new power valve, checked that the jets and air bleeds are clear. Checked the metering blocks are clean. Replaced the float needle whatsits. Levels in the fuel bowls are set right. Tested the accelerator pumps. Everything on the carb seems just fine

I spent a whole day messing about with it and it has'nt made a blind bit of difference!

Does anyone know what else there is to check??

Whatever it is, it must be on the primary side?

Cheers.

[bluesatin]

I got a 750cfm holley if you want it for sensible price. I changed to holley hp a few years ago and it is sitting on the shelf

[BliarOut]

Sounds like the symptoms I had once when I had a leaky manifold gasket. (I'm not telling you what it was on though!) Until someone has a better suggestion have you got access to one of those old Gunson's colourtunes? so you can at least work out if it's running rich or lean?

[menostig]

Same symptoms turned out to be broken electrode inside the top centre of the distributor cap.