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Thu Dec 11, 2025 8:11 pm

Hi. This is my first post and I have been searching these forums for a long time trying to find answers. I have a 2387 powerhaus built motor that is leaking from the right side ida in both barrels. It idles fine. Snail is at 6. Idle 750. 70 idle jets, 120 jet holders, 160 mains, 180 air 42mm venturies, f11 emulsion tubes. It has a malpassi fuel pressure regulator set to 2.5 also. I've swapped the pump rods, exhaust valve in bowls, jets, pump nozzles, with both sides and still only right side leaks. Adjust valves and set timing again. Linkage is adjusted correctly. The thing is that even if the idle stop screw is not touching the arm and I lift it, the dribble stops. I took carbs off the manifold on both sides and checked that the progression holes are covered with the butterfly. They all look to be exactly the same. Mixture is hard to set due to leak. Thank you for any help.

Fri Dec 12, 2025 8:34 am

Hey man,
does it leak from the accelerator "tubes"?
Look down the carb when it runs, is it spraying fuel in the port at idle?
Often that's a problem when the lower accelerator pump bushing has too much play...it gigles sideways and sprays fuel at idle
Otherwise you can try to advance the ignition more so you could and close the choke more at same idke rpm, that could help a bit.
Best greetings from D, Felix

Fri Dec 12, 2025 12:05 pm

Yes it dribbles from the pump nozzles at idle. When I rev the engine it stops for a couple seconds and starts leaking again. Thank you. I will try to advance timing again. How do I adjust the pump bushing play? Thanks.

Fri Dec 12, 2025 6:15 pm

Check your floats. If you have brass ones may be leaking and filling up with fuel. Also I would ditch the 70 idles and try 60's It will run way better with even better mpg's.

Sun Dec 14, 2025 3:23 am

70 idle for 2,4l is ok, maybe you could try 65 but 60 is way to small for ida's...140 holder is a bit weird, normaly a 100 or 105 is more the way to go from the std 120. F2 or F4 emulsion would even do it better than f11.
Checking floats and get those spot on is always essential on IDA's, but that's not the problem here...

When the lower bushing 66 has play that needs a repair with drill out and a new brass bushing... Not an easy task but doable for a guy with good tools .
OR send the carbs to a guy who does excellent overwork like Gary BERG.

The accelerator rod 4 pushes on the lever 29 which contacts the cam 36 on the butterfly shaft, get the carb of and look at the state of those parts and understand how it works. When the cam gets in action the lever lets the rod go and fuel gets sprayed in. Complete other system than idf's.
Often there is even a problem and the bushing on the lever 29 has flat spots and so on...
All that play there gets it movin and the spray get's on!
A adjustable cam could maybe even solve the problem when wear is not extrnsive, but have not tryed these myself till now: https://www.thesamba.com/vw/classifieds/detail.php?id=2741483

There are even exhaust valves available which are not 0, so a min amount get's back in the bowl, you could even try those but before check for wear of the parts described above!

Tue Dec 16, 2025 4:52 am

felix ehrhardt wrote:
When the lower bushing 66 has play that needs a repair with drill out and a new brass bushing...
I think you're referring to the brass bushing that's part of the main carb body. Part 66 in the diagram is a separate part that's there to limit the down stroke of the pump rod. If you've never seen such a small bushing, that's because it was only used on the 46 IDA. Never on any 48 IDA.

Thu Dec 18, 2025 5:16 pm

Yeah, I meant the bushing which is pressed into the carb bottom.

I din't know that 66 is a seperate "loose" part for 46's, never got my hands on one of those unicorns, always thought it is displayed there for reference.
THX Bruce, great info as always! 8)
Best Greetings, Felix