Carb trouble

Skully · #1 (**permalink**) 10-30-2010, 10:30 PM

Does any body have a Proform carb, and if so any problems. Mine has a dead spot , when idling at 1000 rpm and trying to adjust it ,it hesitates before it opens up. Should it be tuned like a Holley. The Proform is a 650 cfm, #778-67199, is the model number. I have a 347 cu, and I am wondering if it is better to go with a Motorcraft or Holley. If it is repairable, could it be the acelerator pump, if so where do you get the repair parts at.

vettestr · #2 (**permalink**) 10-31-2010, 12:33 AM

Yep it can be tweaked like a Holley. What is your manifold vac at idle and what is the timing at idle ?

Check the timing at idle and then tell us what total is at say about 3500 RPM.? If the total is less than 30 with a idle setting around 6 to 8 degrees then it is just mis-adjusted..... Set initial to 14 degrees and total no more than 34* the stumble will go away

Skully · #3 (**permalink**) 10-31-2010, 09:18 AM

Thanks for the info, I will try this.

Karl Bebout · #4 (**permalink**) 10-31-2010, 11:03 AM

That Jeff Classic....he's the bomb.

vettestr · #5 (**permalink**) 10-31-2010, 02:46 PM

Hey Karlos .... whats happening ? Hope all is well on the other side of the world and of course with the good folk down there. I wish you had your bad mo fo back on the road by now, guessing you do too.

Skully,
I hope I am not leading you astray here but I hear this complaint a bunch. Many times the engine is screaming for timing but you have to listen real close to hear it. The timing tab is often off/wrong giving false info after everything gets moved around.

You can try to verify TDC and all that stuff or just go the ole school route. Reach in and give it a hand full of advance, advance until you hear the death rattle under a high load. Then back it down until it stops. When you get her to stop rattling take another 2 degrees out just to be safe then lock her down. They like timing and so will you !!!