Rebel_Heart

On my new 540s, I have an engine that won't idle less than 1500 or it dies. The other engine will idle all day at 800 out of gear and 600 in gear. I had Nickerson do the carbs, and Dean is willing to take a look at it but want to rule out other problems such as an intake manifold leak. He said to change carbs on the engines and see if we have the same issue.

Anyone experience this problem? Thanks.

rdoactive

Check for vacuum leak at base of carb or intake.
Also check ignition timing, both base and make sure you're getting correct advance.

thedonz

change carbs between them first, easiest tell tale, then check for leaks, timing, etc.

mrhorsepower1

Swap carbs like Dean said and see if it follows. If it does only a few possibilities. Vac. leak either on base of carb/carb spacer if your running one or intake manifold. The other thing to check is to make sure there is no fuel leaking out of a booster, last item- where are the fuel mixture screws adjusted at? If they are too lean( screwed in too much) the engine will not idle down properly. Start at 1 1/2 turns out on all four corners. Also be sure that primary and secondary throttle plates are adjusted the same on the amount they are opened. If one is opened way more than the other you may be pulling fuel out of the transfer slot located below the throttle plates. Hope this will be of help.

Dean Gellner

Donman

Since they are new engines, it could be possible that you have a valve adjusted too tight, leaving the valve slightly open...

Happened to me once. Will act like you`ve described.

Rebel_Heart

Great responses. I just spoke with my engine builder and he has adjusted the valve to open more. He now claims that he has had on the muff and it idles great. Hope he is right, because it was really a bear. Thank you.

SB

Seriously, Your idle issues where caused by your rocker arm preload set incorrectly ? Assuming hydraulic lifters.

Are you kidding me ? Sorry to be sarcastic but this burns my butt.

At first, was it someone less experienced and not a professional builder that set the preload ? I sure hope so. This is pre- Engine Building 101.