Very high idle - 440 six barrel

[70sixpkrt]

Make sure the butterflies are not binding up on the manifold to carb gasket. Seen that before.

 

[Righty Tighty]

Thanks! I’m gonna check it out tomorrow I think.

 

[Chryco Psycho]

I assume you have not done this before , so the easy way to remove the carbs is split the fuel lines at the Tee for the center carb & remove the rear carb first , hopefully that is the one not closing 100% & you can leave the other 2 in place . If not continue working from the rear so center carb next & front carb last . Of course reverse the order to install the carbs . Yu will have to adjust the linkage again if you get one of the carbs to close further as the adjustment will change but you will have the linkage disconnected anyway to remove the carbs .

 

[Righty Tighty]

Your assumption is correct. Luckily I was going to start on the rear anyway, since that's the one I suspect is sticking. I also corrected the angle of the kickdown linkage and ordered a different throttle cable bracket.

Thanks for the tips on disassembly/reassembly, should definitely help things along.

 

[Righty Tighty]

While I was able to get the RPMs down by adjusting the timing and linkage, I finally removed the rear outboard to have a look at the throttle plates. The gasket wasn't hanging up at all, but the plates seemed to be hanging open just about .010" or so. Just BARELY enough to be able to see light shining through. I gave a good cleaning with carb cleaner and exercised the shaft quite a few times, also while adding more carb cleaner. The shaft seemed a little gummed up, so my thinking was after a thorough cleaning, a tiny dab of lube where it entered the carb body would help.

I reinstalled the carb and adjusted the linkage and got the engine up to operating temperature, then took it for a test drive around the neighborhood. Idled nicely driving around 15-20 MPH, no big pulls on the throttle though. Upon pulling it into the driveway and placing it in park, no high idle! This was where it was the worst, and it passed the test. Shut the engine off, and NO DIESELING!! I'll be addressing the primary and front outboard tomorrow for some maintenance.

So, while there still may be some small issues to work around, I appreciate the help solving this one.

 

[Chryco Psycho]

Great news !!

 

[70sixpkrt]

When you tighten down the carb bolts, you can move the carb back and forth a tad to make sure the butterflies aren't binding up.

 

[Righty Tighty]

When you tighten down the carb bolts, you can move the carb back and forth a tad to make sure the butterflies aren't binding up.

Awesome, thanks for the tip! Never would’ve thought of that.