I am desperate need of help.

[058]

The tank check valve is a C.C. required deal for all top draw tanks. I would still go back and check fuel pressure at WOT and you must install the F.P. guage as close to the carbs as possible for an accurate reading. When you say the 460 is stock am I to assume it has the D3VE-A2A heads on it? If so then you might want to bump the total timing up to about 35-36 @ 3000-3200 rpms. The engine should have no problem handling that timing as the C/R is only about 8-8.5 to 1 depending on block deck height. I'd also set the initial timing to 15-18 deg without exceding the 36 total. One more thing, get rid of those 3.5 power valves as they may be closing at your maximum rpm leaning out your engine. 600 CFM carbs are IMO too small for a 460. Try a vacume guage under the carbs to check manifold vacume, if the vacume starts to rise as you approch your maximum rpm the power valves will close cutting off the fuel from the PVCRs and you changed to a 3.5 p/v which will close sooner than the 7.5s you removed.

[Dominator Scott]

The tank check valve is a C.C. required deal for all top draw tanks. I would still go back and check fuel pressure at WOT and you must install the F.P. guage as close to the carbs as possible for an accurate reading. When you say the 460 is stock am I to assume it has the D3VE-A2A heads on it? If so then you might want to bump the total timing up to about 35-36 @ 3000-3200 rpms. The engine should have no problem handling that timing as the C/R is only about 8-8.5 to 1 depending on block deck height. I'd also set the initial timing to 15-18 deg without exceding the 36 total. One more thing, get rid of those 3.5 power valves as they may be closing at your maximum rpm leaning out your engine. 600 CFM carbs are IMO too small for a 460. Try a vacume guage under the carbs to check manifold vacume, if the vacume starts to rise as you approch your maximum rpm the power valves will close cutting off the fuel from the PVCRs and you changed to a 3.5 p/v which will close sooner than the 7.5s you removed.
Unless that check valve is inside the tank then there isn't one there. As for the power valves I have rarely ever even dealt with them because I have always removed them on my blower motors. It seems that everyone has a different opinion of what to run for a PV on this application but I am about to the point of eliminating them and jetting up to compensate for it like I have done in the huffer motors in my 32 Dominator. Aside from the blower surge they have always idled just fine.
As for stepping up in carb size,that isn't an option so these have to be made to work as good as possible.
Also the fuel pressure gauge is located right underneath the carbs and is secured to the tunnel ram directly.

[Dominator Scott]

What do the plugs look like? Are they pretty much uniform or are some darker than others.
Looks good by the way.
http://***boat.com/forums/attachment...8&d=1179777540
The plugs are all burnin' lean uniformly. No plug looks very different from another.

[cruser]

I noticed you have vacuum secondary carbs. Are the secondaries opening?

[Dominator Scott]

I noticed you have vacuum secondary carbs. Are the secondaries opening?
Yes they are.

[502 JET]

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!!!

[Dominator Scott]

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!!!
Backfiring through the carb suggests a lean condition correct? This has happened a couple times.

[460 jus getn it]

Backfiring through the carb suggests a lean condition correct? This has happened a couple times.That or the incorrect fuel. I had a backfire threw the carb at wot running on 87. Switched to av gas and 92 mix and the problem went away.

[502 JET]

Backfiring through the carb suggests a lean condition correct? This has happened a couple times.
Backfiring through the carb and you may have blown out the power valves.
How much backfiring? A little stumble or popping through the carbs? Excessive backfiring could be a different problem.
You should install a balance tube between the vacuume diaphrams of the secondaries. It will allow the secondaries to respond in unison.

[Dominator Scott]

Backfiring through the carb and you may have blown out the power valves.
How much backfiring? A little stumble or popping through the carbs? Excessive backfiring could be a different problem.
You should install a balance tube between the vacuume diaphrams of the secondaries. It will allow the secondaries to respond in unison.
Just a small pop once but stumbling before and after that. Checked the power valves and they are okay. I am taking it out after work with a vacuum gauge on it to see what kind of vacuum I am producing. Also I have installed another fuel pressure gauge to verify I am at a constant 7lbs of pressure.