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> Is anyone using a hex bar linkage, twin carbs
930cabman
post Jun 1 2022, 05:37 PM
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A decent 1975 Palma Green came to me last year, from Cali with very little rust and original paint. She was running ok with a single carb. I changed it out to a set of twin 40 IDF Webers and she has not run decent since. The cheapskate in me has considered simply sending Tangerine $400. and getting it right, but ...

I can get a smooth idle at 5 -6 on a snail, but increasing the throttle opening a small amount I cannot get equal air readings from 1-2 to 3-4. Compression ranges from 110 to 125, leakdown ranges from 5%-18%, valve clearances at .006.

The characteristic popping and poor running are the result of this unbalance condition.

thanks in advance
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Robarabian
post Jun 1 2022, 06:29 PM
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Hi Cabman,

The popping and poor running is likely due to lean condition. Popping for sure. Once you have timing, ignition and valves all proper, then you can tune the carbs. Get them dialed in low and work your way up. There is alot of info on dual carb tuning here and elsewhere. Make sure they are on the idle circuit and the butterflies are closed. Go from there. Do it without any linkage on the carbs. Then attach linkage and sync the linkage. Then work the carbs..

Again, lots of reading to do, but it isnt just being unbalanced...


QUOTE(930cabman @ Jun 1 2022, 04:37 PM) *

A decent 1975 Palma Green came to me last year, from Cali with very little rust and original paint. She was running ok with a single carb. I changed it out to a set of twin 40 IDF Webers and she has not run decent since. The cheapskate in me has considered simply sending Tangerine $400. and getting it right, but ...

I can get a smooth idle at 5 -6 on a snail, but increasing the throttle opening a small amount I cannot get equal air readings from 1-2 to 3-4. Compression ranges from 110 to 125, leakdown ranges from 5%-18%, valve clearances at .006.

The characteristic popping and poor running are the result of this unbalance condition.

thanks in advance
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r_towle
post Jun 1 2022, 07:48 PM
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After trying all the x bar linkage..and I know how to tune carbs, I would suggest you call Foley.

BUT, tune as stated above, jet changes may help.
Buy the jet kit, read up and get it perfect.

Only then will you see the slight difference the linkage makes.
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bbrock
post Jun 1 2022, 07:54 PM
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No question the Tangerine linkage is the best, but I've been really happy with the CSP linkage which is reasonably priced. Well, as happy as I'll ever be with anything carb related. Will be going back to FI soon.
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914werke
post Jun 1 2022, 08:17 PM
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(IMG:style_emoticons/default/agree.gif) Ive been using a CSP on anything Im "forced" to apply carbs to.
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930cabman
post Jun 2 2022, 04:58 AM
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Thanks for the replies. Spark timing is good, idle speed screws are about 3/4 turn in, mixture screws are about 1 - 1 1/2 turn out. It seems as though the carbs are not being activated at the same rate. I have a CSP setup, but mistakenly ordered assembly that works with a 911 style fan. I may send it back or put it up for sale here.

Tangerine will be my first call today.

I have a pile of FI (both D and L jet) stuff laying around, it may be smart to inventory the stuff and give it a try.
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Superhawk996
post Jun 2 2022, 11:56 AM
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QUOTE(930cabman @ Jun 2 2022, 06:58 AM) *

Thanks for the replies. Spark timing is good, idle speed screws are about 3/4 turn in, mixture screws are about 1 - 1 1/2 turn out. It seems as though the carbs are not being activated at the same rate. I have a CSP setup, but mistakenly ordered assembly that works with a 911 style fan. I may send it back or put it up for sale here.

Tangerine will be my first call today.

I have a pile of FI (both D and L jet) stuff laying around, it may be smart to inventory the stuff and give it a try.


@930cabman -- if you have 73' early 2.0L D-jet stuff, reach out to @second wind . . . he's looking for ECU / wiring harness

http://www.914world.com/bbs2/index.php?showtopic=359954
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930cabman
post Jun 2 2022, 05:38 PM
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QUOTE(r_towle @ Jun 1 2022, 07:48 PM) *

After trying all the x bar linkage..and I know how to tune carbs, I would suggest you call Foley.

BUT, tune as stated above, jet changes may help.
Buy the jet kit, read up and get it perfect.

Only then will you see the slight difference the linkage makes.


I spoke with Chris this morning and too bad he has none in stock, but informed me in a couple weeks he will be able to ship me a setup. I feel my jets are close, at least the idle circuit
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