So I figured I'd clean out my carbs, and see if I could get to the bottom of my 'rough idle' problem. It turns out the bystarter valve diagphram (sp?) on the #3 carb had a tiny hole in it. I repaired it, set my float levels, and re-installed the carbs.

It took some serious cranking to get it started- a lot of backfiring, playing with the choke, etc. before she finally lit. Now, she idles at 4000 rpm + with the idles speed screw completely loose. While it was running in this condition, I noticed fuel getting past the needle valve in 3 of the 4 carbs.

Sere aresomequestions:
1. Does the leaking fuel and super high idle mean that my floats are improperly adjusted? If so, what point on the float do I use a reference when measuring? Is it the highest point on the float when it's barely touching the needle?

2. Is there some 'default' carb sync setting I should be starting out with? I noticed turning the sync screws would lower the rpm some, but not enough. And it would just jump back up into the midrange even after I let go of the throttle.

Any tips, advice, opinions you guys can offer would be most helpful. I'm a halfway decen mechanic, but these carb issues are a little beyond my experience at this point.

Thanks in advance!

 

Did you replace the O-ring seal, washer and springforeach Pilot Air Screw?

How many turns outare the screw set?

Theyshould be 2-1/2 to 2-3/4 turns out for each pilot airscrew.

And yes the screws are a little sloppy or loose at that setting, so I put one drop of super glue on each screw where the screw meets the carb body, 1 drop is all you need to hold the screw tight.

If you have the floats adjusted to "high" then yes, you have raised the fuel level in the float bowl and that fuel has to go some where, out the pilot air screw, hmmm it's possible.

I would also think that if the floats were adjusted to highyou would also have fuel leaking at the float bowl gasket.

Somewhere in the manual it shows how to adjust the fuel floats, check the service manual.

I would get the floats back to the stock position and start over.

You can create a high idle speed from the carbs being out of sync and youwill NOT be able to adjust it to a slower idle speed.

So to answer one of your questions, yes an out of sync carbcan run fast.

Each time you remove the aluminum airbox plate that screws to the carbs, you must sync the carbs.

Good luck and go buy a carb sync tool $40.00 bucks, it will make your life much easier!

Oh and have fun getting those little screws out where the sync tool mounts to the intake, those little buggers can be real fun sometimes!

 

I figured the sync would be an issue. The pilot screws are set at 2 1/2 turns out from seated, per the manual for default settings. The fuel is being drawn by vacuum past the needle jets that are connected to the plastic doohickey that blocks the throttle body at lower rpms.

So, I'll guess I'll see if I can sync the carbs and get it to idle somewhat normally...