Any ICT 34 gurus out there?

[MConverse]

Vehicle is 1969 Type 3, with a 1641 engine, and a DDB over the top exhaust system.

Came to me with dual ICT 34's that had worn throttle bushings, and a warped linkage. I took them to a machinist and had him re-bush them, installed a new linkage, put in a carb-rebuild kit, set the floats at 7mm, and new jets (57 idle 140 main), No vacuum (009), and there is a balance hose between the two carbs.

I'm having some issues synchronizing the carbs and getting the idle down to an acceptable level, and I'm sure most of it comes from my lack of knowledge about carbs in general, and how to tune them.

The right Carb is flowing more than the left carb. With the idle speed screw not touching the throttle lever, and using a unisyn, the little float is about 1/3 of the way up from the bottom of the unisyn. If I do the same on the left carb, the float stays all the way down.

Q1: Does this mean the throttle plate on the right carb is bad?

Q2: Should the carb have practically no flow with the throttle plate all the way closed like the left carb?

Q3: where do I get new throttle plates for these carbs? or do I have to replace the entire thing?


Lastly, is there anything I can do about the lack of chokes on these? I hate having to sit in my driveway for 3 minutes feathering the throttle until the engine warms up enough to hold and idle.

I'm into these carbs almost 200 dollars between jets, rebuild kits, machining, and the linkage. I'm willing to do what it takes to get these guys running correctly, But I'm already thinking about upgrading them to something with chokes, and getting an svda distributor.

What other options are there out there? I've looked at piecing together the correct FI system, but them parts are rare, and getting rarer.

This may have to wait for Colin's trip, but I'd rather fix it myself if I can.

Mike

[Amskeptic]

I'm having some issues synchronizing the carbs and getting the idle down to an acceptable level,
Q1: Does this mean the throttle plate on the right carb is bad?
Q2: Should the carb have practically no flow with the throttle plate all the way closed like the left carb?

I've looked at piecing together the correct FI system, but them parts are rare, and getting rarer.
This may have to wait for Colin's trip, but I'd rather fix it myself if I can.

Are your throttle links disconnected as you attempt to synchronize idle air flow? Occasionally the throttle links will fight each other and pull one carb open while the other is closed. Disconnect them temporarily. If the right carb still pulls dramatically more air, recheck valve adjustments, manifold gaskets/tightness of flanges. Manifolds love to warp at the heads and allow air in. That would be a problem on the left side by the way, if the right keeps pulling more air with the stop screw backed out as you stated.
These carbs should only give a very low idle with the throttle stop screws backed out. Other, more subtle causes of air flow issues can be valve guide wear, leaky plug porcelain-to-shell, venturi placement, and screwed up passages in the carb itself.

Yes, I do love my electronic fuel injection. The parts are readily available used, as people tear the FI out all the time. Get em while you can.
Colin

[MConverse]

Throttle links are disconnected while trying to sync them.

I'll check for leaks with some starting fluid around the carb to manifold mating area, and manifold bases.

[MConverse]

Thought I'd post an update, I found the base of the right carb was a bit concave, but it was late, and seeing how this is my DD, I had to get it back together so I can get to work and home again. No time to play with it this last weekend, but If the weather clears up, I'll be back on it this coming weekend.

Plan is:

Remove carb, attach sanding paper to a piece of glass, and vigorously sand until base of carb is nice and flat.

Q - will any gasket I get from the local flaps be ok, or is there a name brand I should be looking for here?

[Amskeptic]

Q - will any gasket I get from the local flaps be ok, or is there a name brand I should be looking for here?

Any properly impregnated paper gasket should be fine. The cardboardy tan gaskets are not fuel resistant, the grey or green slightly waxy ones are.
Colin