Re: Terriable backfiring
 

steve s, Fred K-OR, GPierce I would suggest that you three re-read my #41, #45 and #53 posts. I know I started this entitled "Terrible backfiring" but has gone to low compression. However, I decided that a compression check was in order. When I found #3 having 48lbs. pressure then I decided a "Blow Down Test" was in order. Having found air leaking from #3 that was when I decided to remove the head, NOT for the "Terrible backfiring" but because of the leaking from #3. It was going to have to be done now or later.

Steve s In post #53 second paragraph, last sentence I said: "I don't think it has anything to do with the backfiring". Also in post #53 the last sentence of the first paragraph I said: "I'm on another mission trying to get head off but when that is done I will be opening the carburetor up". I have not because of all the problems I had removing the head.

I appreciate ALL of your responses to my problem and look forward to those of the future.

Re: Terriable backfiring
 

Did you ever get this problem solved?

Re: Terriable backfiring
 

Found the cure to my backfiring . The throttle was not closing all the way at the carb ,corrected that problem and no more backfiring.

Re: Terriable backfiring
 

Thanks for the update, good info.

Re: Terriable backfiring
 

How about internal distributor wiring? If insulation frayed can cause a short and backfire.

Re: Terriable backfiring
 

I have always read on this site to get back to the board when the problem has been resolved and how. Well here I am.

A little background. Engine did a lot of backfiring and rough running. I did a compression check: Cylinders 1, 2 and 4 had 60 lbs. in each. 3 had 48 lbs. I followed this with a blow down test. This showed air being blown from #3 to #4 cylinder. I reversed that process and #4 was now blowing into #3. This indicated to me that the head gasket was blown. WORKED at getting the head off a considerable time but finally accomplished that. Found head gasket intact. Looked at valve adjustment and found #3 exhaust shut. At this point decided to take valves out and lap seats but #3 exhaust didn't look to good after the lapping so had a machinist come and CUT the seats with the engine in the car. Installed all NEW valves because old ones had VERYnarrow margarine's. Now engine didn't run well and thought it was a distributor problem and went on to change a condenser in the second distributor. Still not running well.
Changed with a different carburetor from a engine that ran well but still did not help. Then assembled another carb. from the shop with parts I had on hand. Took car out yesterday for a ride and picnic with my buddy and his wife and of course on to Ice Cream. This car runs well and sure am now a happy Model A Owner!

Thanks to all for your advice and suggestions!!

Re: Terriable backfiring
 

So it was the carb?

Re: Terriable backfiring
 

My roadster would miss badly when I was on a trip to TX. I had all kinds of help changing gaskets, carbs and distributors. It was so bad I was towed part way and yet we never found the culprit. Then on the way back it somehow seemed okay and I made it home and a year or so later It suddenly did the same thing again and I had two guys helping me sort it out. As I raised the hood on the drivers side one of them saw my alternator and as he said, "Oh, you have an alternator," he reached in and touched it. The wire to the fuse fell out of the crimped holder that holds the wire to the outlet on the alternator. No more problem after I crimped the holder a bit tighter. That was in 2008, Still working well.

Re: Terriable backfiring
 

My car had a bad back firing problem , no power. Turned out to be points and the coil.

Re: Terriable backfiring
 

I had a similar issue and found that the lower shaft of the distributor had worn and it was causing the issue. The shaft only fits in one way but the groove had so much slop in it that it was wobbling and causing the car to run terribly and back firing like crazy. Cops came by and said they had reports of shots in the neighborhood.

Re: Terriable backfiring
 

Yes that's what I said. When the carb. I had was put together and float set it seems to run fine. I have only driven it maybe 30---35 miles but feel good about it.