I am desperate need of help.

[058]

As suggested above you need to connect a vacuume gauage and read manifold vacuume. You may be dumping too much fuel not leaning out. If that is the case you can get 1.5 pv's. and they will hold shut for you until w.o.t..
If you cruise back to the dock and do plug checks the plugs will clean up and not give you an accurate picture of what is taking place.
Prolong crusing at 4900 rpm and shuting off the engine and check plugs see if they are sooted up.
!!!WARNING YOUR BOAT MAY GO OUT OF CONTROL IF YOU SHUT IT OFF AT 4900 RPMS!!!!:2purples:BE SAFE!!!1.5 power valves would probably never open since the carbs are relativly small for that application. If the 600cfm carbs are to be run then I suggest eliminating the p/vs and jet up accordingly. IMO the 3.5 p/vs are closing at or close to WOT further cutting off the extra fuel from the PVCRs. As I suggested above run the 7.5 or a 6.5 P/V for an earlier opening. It would also help to know what the PVCR diameter is.

[Dominator Scott]

1.5 power valves would probably never open since the carbs are relativly small for that application. If the 600cfm carbs are to be run then I suggest eliminating the p/vs and jet up accordingly. IMO the 3.5 p/vs are closing at or close to WOT further cutting off the extra fuel from the PVCRs. As I suggested above run the 7.5 or a 6.5 P/V for an earlier opening. It would also help to know what the PVCR diameter is.
The stumble feels relatively the same with the 7.5 or 3.5 power valves in the carbs. To be honest I have been messing with this and test running it so much I am losing my perspective and am having trouble telling any differences now.
I personally would rather plug the damn power valves and just jet the snot out of it,but people have advised me not to because of idling issues which is important considering the channel my father lives on is "no wake" for a good 200 yards and I don't want it loading up and dying on him because of idle difficulties..

[Squirtcha?]

Have you checked the tunnelram for leaks? If you've got an air leak somewhere that could account
for the lean condition. Are the carbs snug on their bases?
I reckon there are lots of ways to check for leaks. I've always heard spraying WD-40 around the
mounting surface and listening for it to idle down, or starter fluid and listen for an idle up.
Personally the starter fluid thing would make me a little nervous.

[OverKill]

Have you checked the tunnelram for leaks? If you've got an air leak somewhere that could account
for the lean condition. Are the carbs snug on their bases?
I reckon there are lots of ways to check for leaks. I've always heard spraying WD-40 around the
mounting surface and listening for it to idle down, or starter fluid and listen for an idle up.
Personally the starter fluid thing would make me a little nervous.
OH come on Dan remember when we were trying to get your daughters friends jeep to start. We used Starter fluid LOL it sure was funny when that thing was trying to turn over and POP!!!!. It makes me laugh writing this.

[OverKill]

Scott I think I know what the problem is. It's probably that skag slowing you down. LOL. Hey just to let you know I also have a tunnel ram and Most might disagree but vacume secondaries don't work so good on tunnel rams. I had a 750 vacume and got the same thing MIXED SIGNALS, sounded like pop corn. Went to 850cfm mechanical and all was fine. Just a thought

[502 JET]

The stumble feels relatively the same with the 7.5 or 3.5 power valves in the carbs. To be honest I have been messing with this and test running it so much I am losing my perspective and am having trouble telling any differences now.
I personally would rather plug the damn power valves and just jet the snot out of it,but people have advised me not to because of idling issues which is important considering the channel my father lives on is "no wake" for a good 200 yards and I don't want it loading up and dying on him because of idle difficulties..
Plugging the PV's will not affect your idle mixture. Niether will putting larger jets in. The engine most likely will still stumble with the PV's plugged and larger jets because at part throttle cruise the carbs will be dumping too much fuel.
The number on the PV indicates how much vacuum you need to hold it shut. When vacuum drops below the PV's number the valve opens enrichening the mixture.
EX: A 7.5 pv=7.5" inches of vacuum drop below that and the valve opens enrichening the mixture.

[cfm]

Any dual 4bbl set-up with vacuum secondaries should have vacuum line connecting the two vacuum actuators together. This way, they'll work at same time. Of course, assuming both have same spring in them too. Holley sells these vacuum housings.
If fuel psi is fine, then the whole system before the guage is keeping up and fine. We need to check delivery after guage. IE: needle and seats and jetting and filter if any after the guage.

[Dominator Scott]

Okay guys I took the boat out last night to get all the necessary info.
1)At idle the motor is at 10-11" of vacuum.
2)When you punch the gas the vacuum drops to zero and gradually climbs and at 4500RPM's which is all she pulls before it starts stumbling she is at about 3-4" of vacuum.
3) Fuel pressure remains at a constant 6-7lbs of pressure under acceleration.
Here is another thought. We had to pull the distributor to remove the old intake because the studs in the heads prevented us from sliding it back from the distributor and removing it. We never touched the points and the distributor dropped back in the original setting after a few tries. But is it possible the points are out of whack now?
Also since there is no little window on the distributor cap for setting the dwell when it running,how do you set the dwell? Or isn't there a dwell on this system?
Whats your thoughts.

[cfm]

Okay here is the deal. I recently bought a tunnel ram with dual Holley 600's for the BBF 460 and I am having a hell of a time tuning it in. (LEAN CONDITION)
I should add that jetting the carbs up,switch to the 3.5PV and new fuel pump has helped the lean condition but at 46ooRPM's she still falls off and sputters which sucks because I still have a 1/3 throttle left to go.
PLEASE HELP!!!!!!
For schits and giggles (and free) try closing your plug gap to .025"-.030" . if I remember right you still have a points ignition. Maybe it does not have enough juice ? If the small gap gives you some more rpm before breaking up then you found the issue. Fix it and the re-gap back to normal of course.
Oh, not sure if you mentioned this, but put timing light back on it and make sure you are getting full advance.

[cfm]

LOL. You answered one of my questions while I was reposting- Yup you have points !!!! That was funny,lol.
Sometimes ignition systems will seem like fuel issues and vice versa. Let's get that ignition system 100% since you do not know if it is.