Spark Advance Surprise

[Marcus]

Gentlemen: Ol' Clyde, 29 CCPU, has been running perfectly until last week when placed into the State Fair. Noticed gas dripping from carburator, but the gas line petcock was fully closed - obviously not sealing completely. So, drained the tank for the duration of the show. Today, put a gallon of gas into tank (enough to load Clyde onto the trailer and take him home). When I started him up, near constant backfiring and very little throttle response..... Until, that is, I pulled the spark lever all the way down. Then, he ran perfectly and loaded easily on the trailer. I suspect the two problems are coincidental, and can easily diagnose and repair the first; however, (knowing that I should not have to pull the spark advance all the way down) what could have caused this and what should I do to repair it??

[Jacksonlll]

First, take a good look at the dist. A quick look at the points, the gap, and then take off the upper plate and check the little black wire. It may have an intermittent short. The backfire would result from a make/break of that circuit . All easy to check. If you are careful, you may not have to retime it.

[1crosscut]

If it was at the State Fair I wonder if someone while you were away fiddled with the distributor. Are all of the spark plug wires attached as they should?
Jackson has given some good direction as to what to check.

[Marshall V. Daut]

If the points block has worn down from lack of lubrication grease or because it's a poorly-made piece, the points gap will close up. If closed up enough, the engine will be hard to start and will pop and throw fits. A drastic points gap change will affect the timing, too, which is why you had to advance the spark lever more than you're used to doing to achieve power. I'll bet you'll find the points gap has closed up dramatically.
This has nothing to do with your dripping gas. That's an entirely different problem. And for once I can say without fear of contradiction, that even though 90% of carburetor problems are electrical, in this case, your dripping problem falls into the true fuel category. Bad condensers and coils don't cause carburetors to drip.
Marshall

[SuperDave]

make sure the spark advance rod is not touching #3 plug when retarded.

[Marcus]

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Excellent advice and thank you all!
Jackson - I'll do as you suggest.
Dave - the truck was fenced off for display, and I don't think touched.
Marshall - I think I pointed out that the dripping was coincidental; however, I value your comments (with the smiley face properly noted)! I am thinking you and Jackson are correct on the points issue.
SuperDave - never thought about that! (Wish I had had the time to look you up last week: delivered a car to my daughter in Palm Bay to replace her hurricane destroyed one - a less than stellar automobile in the first place - storm did her a favor!)
I'll have time next week to inspect Ol' Clyde, and shall report my findings.

[Jacksonlll]

Hey Marcus, I'm from Hammond, La. In Mich now, but we were not too far from each other. Have fun with that A.

[Marcus]

Jackson - Sorry I missed you! Lived in Royal Oak back in the 60s; worked at the GM Tech Center, Warren: purchased a "Royal Tiger GTO" in 67; 389 / tri-power / 4-speed / convertible: terrorized Woodward and Telegraph! Had to let it go when Uncle demanded my attention in Vietnam - probably for the best, as I would have killed myself (or someone else) as it was......

Loving the CCPU; sold the '31 Slant in the avatar, but too many toys still.....returning to my roots now, with three mid-60's Mustang Converts......plus the '47, and the WWII / Korean Jeeps (4), plus..........well - TOO MANY!

Let me know when / if you get back this way: I own the coldest Iced Tea in Mississippi!