carb idle tuning: neutral or in gear?
 

I can't find an idle setup that will maintain a reasonable idle in gear and in neutral. I can't find the setup to maintain idle in gear and out. I need soo much extra throttle opening to stay running in gear (25" Mirage / 24' V / 800 Holley, mild 502) that I am far far away from the proper idle transfer slot opening. I've only got a 2 corner idle setup, but I've played with every combination or primary / secondary throttle shaft positions I can think of.

Is this normal? Should I set the proper transfer slot opening in gear or out?

Re: carb idle tuning: neutral or in gear?
 

I set mine by max vacuum + 1/4 richer. If this don't get you where you want to be then you will have to look at more base timing to give you a stonger neutral idle at 7-800rpm. Obviously you dont want more total timing so depending on your distributer is how you go.

Re: carb idle tuning: neutral or in gear?
 

What model carb? choke or no choke? Did it work before?
I set my idle in gear tied to the dock. 650-700 in gear. 900-950 in neautral.
Use a vac gauge. If you cant get it to work with 30 thou max at the transfer slot your gonna need to drill holes in the butterflys.

Re: carb idle tuning: neutral or in gear?
 

DanB,

I've got a 4150 series 800 cfm. Probably a marinized 04780. 2 corner idle with a fully manual choke. It has never worked quite right.....still trying to dial it in. I end up with 1500rpm out of gear and 900 in gear. I dont' want to run it much lower. I can adjust air with the secondary blades and not drill holes, but I've tried a thousand combinations and just can't get it right. I may try some more initial timing and keep an eye on the total. Not sure what I'm running now.

Buck

Re: carb idle tuning: neutral or in gear?
 

There are people here running 18* or more initial timing to help with this problem. You have to find out what your total timing is and where it is all in by rpm, and go from there. Might need reduction gear starter if you get too far up there.

Re: carb idle tuning: neutral or in gear?
 

Pull the metering blocks and be sure all idle passages are clear. Use a high pressure air hose to blow them out. Be sure the o rings are on the fuel transfer tube and are sealing.
If it never has worked right it may be time to get a new one. Do it before you wreck the drive shifting in to gear at 1500. Be real careful advancing timing. Thats a good way to melt pistons.

Re: carb idle tuning: neutral or in gear?
 

Not suggesting that he add more total timing. Just more base timing to smooth out cam effect. Depending on ignition sysytem, that could mean diff spark curve or advance stops or module etc.

Thats why find out where you are at now. Timing at 800rpm, 3000, 3500 etc.

Re: carb idle tuning: neutral or in gear?
 

600rpm difference????? are you sure you don't have a vacuum leak????

Also, that will destroy a drive in a hurry.

Re: carb idle tuning: neutral or in gear?
 

I'm using a secondary metering block WITHOUT idle mixture adjustment (2 corner idle). Does that mean it still feeds fuel to the secondary idle port and is not adjustable and contributes to the total idle or that I idle only on the primary side.

I can get the engine to idle both in gear and out at 900, but I cannot use the same throttle position. Is this normal?

Don't worry.....i shut off for every shift.

Re: carb idle tuning: neutral or in gear?
 

No neutral safety switch :eek: .be careful