Couple of questions about 70 engine woes

Hello... The extended family has this dune buggy homebuilt from a 70 Beetle that gets passed around to the kids but so far from one to the next that nobody even really knows the others... bunch of hillbilly farmers spread out that don't like to see anything die as long as someone can use it.

At any rate, my kid is at the age of interest and we're on lots of acreage, so... since I drove lots of Beetles way back when (not in last 25 years or so) it has arrived in my field. So... I'll be asking a few questions as I have had many things commandeer the brain cells that used to store the VW facts. 8-l

First: The throttle on this thing starts increasing for no good reason every now and then to the point that I can rip up a steep grade without my foot on the gas, but moments later just putts along. Sometimes hitting the throttle will kick it down others it won't. The fast idle/choke is a non-factor as they pinned it open and out of the way. I thought it was the vacuum operated throttle thing that they disconnected the hose from, so I disconnected it's linkage with no joy. I am leaning toward the vacuum advance, but I wanted to post first before I just start messing around with that. Carb is a Solex 30 PICT 2. I also seem to remember something from back then about shimming the fuel pump and notice they've worked on it (very clean on a dirty dune buggy engine) and wondered if that could cause a varying throttle somehow (not likely, I'd think, but it should be noted)

Second: When the engine gets hot it doesn't want to crank very fast. I assumed their battery was dead when it cranked in slow bursts such that we could not restart it in the middle of the field after stalling (getting used to clutch not engine woes), but noticed it cranked fine in a little while. So I controlled a variable and stalled it at the top of a grade and tried to crank... no good... but it caught in gear to start relatively easy. Does this follow any VW patterns?

Thanks for any input.

Reply to
rdoc
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Welcome aboard!

The idle rise could be due to a vac leak. (My first guess was the throttle positioner you disconnected:-)

Slow crank when hot: Bring some gloves along and try to turn the engine by hand when hot. (Do it cold so you know the difference.) That should steer you one way or t'other.

Speedy Jim

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Reply to
Speedy Jim

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