zenith carb settings

[g sturgill]

Hi all. First, let me tell you of a serious mistake that damn near resulted in a major fire and possibly a lost Porsche. I replaced my CIS system, (73 911T), with a carb set-up using Zenith 40 TINs. I installed plastic velocity stacks and rain hats with a screen filter and the engine ran reasonably well for about a year. Yesteday, it was about a 100 degrees and I drove about 15 miles when the engine started missing, bucking and suddenly about 3 cylinders quit firing and the other three started running wide open. Fortunately, I was on a rural road and was able to pull over. I immediately shut it down and ran to the rear while smoke started pouring out of the right carb bank along with a nasty crackle/hissing sound. I don't think it ever caught fire, but after having towed it home and removing the rain hats, the damage was serious. Both sets of velocity stacks were melted along with the top portions of the carbs. Totally trashed.

I turned the engine over by hand this morning and there's nothing unusual going on in terms of sound or feel. What are the chances I've done major damage? My inclination is to replace the carbs, (without velo stacks), and hope for the best. Thoughts appreciated. g

[1976 TN Porsche]

Give Paul Abbott a call at Performance Oriented or look him up here ( 1quicks ) 530-899-8371. He can help you.

[LakeCleElum]

Damage? I doubt it...I had an engine fire in my 73.5 once and damage was limited to burnt hoses and wiring. I caught it quick like you did.

Cause? Maybe high float level, overflow and backfire?

I have an extra set to TIN 40's on the shelf....