Idle RPM
 

What is the highest neutral setting( rpm ) for a Bravo1 to shift smoothly without any cone clutch damage.. My 502's with a mild crane cam and dual plane performer intakes used to idle @ 650 in forward gear without any problems, no loading up or reversion..even with the silent choice on or off. Now I changed the intakes to Holley single planes and it doesn't like to idle..could be loading up or slight reversion especially with the silent choice on..:eek: Could it be the single plane intake manifolds run richer??..leaner?? I have a 1" swirl torque 4 hole spacer underneath the carb. 4 corner idle screws.. each turned out 1 turn idles fine when put in gear dies.. Turned them out each another 1/2 turn.. idles in gear but seems to load up..until i rev up and clear out.. Is this fuel load up or can I have a reversion problem by changing the intakes.. The cam specs are 558 lift 236 224 duration @ .050 114 LS.. very mild

what's the vacuum reading at idle with the new intake? You may need to change your power valve

1/2 a turn on those screws on a 4 corner is a pretty big adjustment. Typical Holley idle mix adjustments are done in 1/8 turn increments.

I agree with checking manifold vacum and PW rating but I would also check base timing if it likes to stall when shifted.

timing
 

What is your timing set to SB 10-12 degrees. The 4 corner adjsutment is for fuel so more turns out more fuel... sounds like a fuel shortage and to big primary jets. do you have drop boosters in the carb or stock?

900rpm in nuetral will be fine to shift. My last 2 boats idled around 900rpm and I had no problems with the drives. Over 1000rpm and you will have issues.

Carbs were built by nickerson performance..They are flowed to my engines based on the old dual plane manifolds. Acording to Nickersons they start with 1 to 1/4 turns out on each screw..At 1 turn out, it won't idle.. At 1 1/4 to 1 1/2 turns out it idles fine until you put it in gear @600 -650 rpm..Then it seemed to load up and not sound right. As for the timing.. Msd 6m2-L with 34 degree locked out @ idle.. The problem was there before the msd system..No change with the MSD..
I did notice with the silent choice in quiet mode, in gear, it didn't seem to load up. When i opened the exhaust then it seemed to not run right..

The power valve is 6.5 primary,(new just changed it ) no Power valve secondary.. I will check the idle vacuum... The boat runs great after 1000 rpms.. No miss Runs strong..Could it be a vacuum leak..It does idle down.. No popping or whistle..

I sent the carb to nickerson and they said it was fine. They lowered the primary jet down too 75 from 76.. I have to try it out this week. They also said its reversion.. Water creeping up the pipe using the silent choice mode..If this is true then why not with the dual plane intake ?? Could this Holley single plane intake cause reversion ??