Stuck idle mixture screw

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friedman
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Re: Stuck idle mixture screw

Post by friedman » Tue Oct 16, 2018 8:16 am

Just an update, no luck so far. Soaked the carb base in a 50/50 solution of ATF and automatic trans fluid for about a week with no luck and that included tapping on the screw head with a screw driver and small hammer. Currently taking a bath in a can of Berrymans carb cleaner.
Carl in Virginia
80 spider
86 Bertone
77 X1/9
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friedman
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Success!

Post by friedman » Wed Oct 24, 2018 8:44 am

I played with this for what, a month? The 50/50 mixture soaking did nothing. The Berrymans did nothing, tapping on the crew head did nothing. I think heat is what worked. I grabbed the toaster oven and brought it to the workbench and put the carb base in there for about 15 minutes at 400 degrees. When it cooled off I tried it and the screw turned a little bit, about 15 degrees but then went no further in or out. By now the screw slot was pretty beat up. The screw sits in a deep tube like extension cast onto the carb base and I cut it off flush with the carb base so I could get a tool on the side of the screw head. Oddly enough the screw was very lose at this point and came right out. The threads looked fine so I don't know what had the mixture screw locked up. Found another mixture screw in my parts pile with the same nose configuration and put the carb back together.
Carl in Virginia
80 spider
86 Bertone
77 X1/9
fp55scca
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Re: Stuck idle mixture screw

Post by fp55scca » Wed Oct 24, 2018 9:50 pm

— Great feedback Carl and Well done! The only downside: your toast will taste like Berrymans s and PB Blaster for a while....
Jim
Jim Scurria
Norfolk, VA

1972 Fiat 124 Spider
1971 Spider - SCCA FP-24
1974 Fiat 124 Spider
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bartigue
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Re: Stuck idle mixture screw

Post by bartigue » Thu Oct 25, 2018 6:52 am

friedman wrote:
Tue Oct 16, 2018 8:16 am
Just an update, no luck so far. Soaked the carb base in a 50/50 solution of ATF and automatic trans fluid for about a week with no luck and that included tapping on the screw head with a screw driver and small hammer. Currently taking a bath in a can of Berrymans carb cleaner.
The 50/50 should have been acetone and atf. Regardless I’m glad you got it unstuck - on my exhaust manifold I had to break and drill four of the six studs.
-----------------------------------------------------------
Brad Artigue
1982 Spider 2000
I've restored, worked on, sold, bartered, and bled for:
1970, 1979, 1980, 1981, 1982 124 Spiders -- 1969, 1970 850 Spiders -- 77 X1/9
http://fiat.artigue.com
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friedman
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Re: Stuck idle mixture screw

Post by friedman » Thu Oct 25, 2018 8:33 am

The mix was acetone and ATF.
I have had to drill out exhaust manifold studs and I never get the new stud holes lined up with the old ones.

Jim, the big fear was the wife finding out!
Carl in Virginia
80 spider
86 Bertone
77 X1/9
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