Carb issues pt. 2/Holley 4160 750 cfm

« **on:** May 04, 2011, 09:19:54 PM »

Well thanks for the replies on my first post! The advise was right on the money, but didnt have clue what I was doing (kinda). Removed the carb and took the bowls off. the prim bowl was wet, but the secondary bowl was dry. Probably the reason the secondaries were'nt opening up

Bought a trick kit and got most of the carb put back together, but there is 2 small cork pieces and not sure where they go?? Any info would be appreciated! Thanks. Can post pics if it helps, but just got home from work...

« **Reply #1 on:** May 04, 2011, 09:45:21 PM »

they go around the air bleeds in the primary metering block...those little brass flat head screws on the side of the carb...one on each side

« **Reply #2 on:** May 05, 2011, 08:05:51 AM »

If the piece is very thin like .030 it could also be a gasket between the vacuum secondary diaphragm housing and the carb body. Sometimes these are made of gasket material and sometimes cork. Pics always help.

« **Reply #3 on:** May 06, 2011, 09:00:46 AM »

Vac. secondary carbs will never fully open the secondaries at jetboat RPMs unless you run an extremely light spring in the diaphram, then you will have a bog on acceleration as they will open too quickly. The additives in the fuel(alcohol or MTBE) will harden the sec. diaphragm in short order too. If you insist on using a vac secondary, plan on replacing the diaphragm every 3 to 6 months. No happy medium here, use a double pumper, you will be much happier. It is hard to overcarburate a jet motor, get an 850 or HP 970, even for a stock motor. The larger primaries allow you to cruise on plane on just the primaries, something you can't do with a smaller carb, especially a Quadrajet! TIMINATOR

« **Reply #4 on:** May 06, 2011, 03:11:59 PM »

Thanks for the replies. There are so many gaskets and o-rings, one can easily get confused! Mounted the carb and so far so good. It fired right up! I will take it out next week and so how she does. Timinator put maybe I should ditch my carb and go with a double pumper. Would it be better on fuel economy and power? I'm running a BBC. I tracked down some previous owners, but all they new was it had a big cam. Took off the valve covers and it had GM performance heads and Crane roller rockers. When I took the carb off I looked into the intake (Weiand) and you could see some porting had been done. Also has a Bassett pan and new twisties. All braided lines with a stinger ingnition (havent heard of it). Anyways if you have any input I would appreciate it!!