Alcor-I installed a see through glass in line filter on the fuel line from the tank pickup to the first filter. The glass showed what I believed was happening, air in the line. I retraced my steps and found that my original problem was a bad check valve. When I was first trying to fix this I took the check valve out and replaced it with just an open fitting, figuring that would fix the problem. It turns out that the lack of a good check valve causes siphoning of gas back into the tank from the filter every time the motors are shut off. The filter is higher then the fuel level in the tank. When I was running at high RPM for extended periods, the filter would run low on fuel as the air prevented a good suction from the tank. With a good check valve, air can work it's way out after running for a while. With an open fitting, the air would return whenever I shut the motor off. I replaced the open fitting with a new check valve and now the glass filter shows full with no air. I still have to run the boat hard to verify that the problem is fixed but I think I got it.

Jersey - Where's the check valve your speaking of locked in your system, I'm not familiar.

I've taken on carbs apart (on the worse engine) and didn't find anything. The filters were clean and I've blow all lines out and installed the fuel pressure gages on the dual pump manifold at the carbs. Blew backwards into the tanks and will run it in the monring to see if that made any difference.

The carbs have a 3752 B number stamped on the top and the throttle body has a 12R 4770 B stamped at the base. Tried to look them up on Holley site but couldn't find any of those numbers. They have "71" jets in one side and "80" in the other. Any idea if these are close to sounding right for 454's? Based on everthing I've found on this boat so far, wouldn't surprise me to find out that these are automotive carbs, not sure if that would make a difference or not. They've run pretty good but they still may not be marine carbs. Will let you know how I make out tomorrow.

Al

Hey, at this point, I'll try anything. Took they off and cleaned them again and tight the hell out of them. Will see if that helps in the monring.

Al

Alcor-the check valve is located on the fuel tank. It is where the fuel hose attaches. Take the hose off and unscrew the fitting. The check valve is part of the fitting. New ones cost $11-$12. I ran the boat today and so far it's ok. Looks like it was the check valve and then air in the line.

Got it. Decided to have an alternator checked and it was found to be erratic. It would only produce 13 volts tops; dropped from there occasionally on the test machine to about 12.5 and also indicated that it had a bad diode, sometimes it worked then it did then it did again, kind of like the problem I'm having. A new alternator on the machine showed 14.5 volts which the guy said was what I should be getting. Replaced it this evening too. Will run it in the morning. Man, glad to hear your's appears to be solved, now good enjoy it! I'll let you know how I make out.

Al

Well after a couple of weeks of trying this and that, looks like I finally got them running like a top; turns out it was a combination of a number of small issues: here's what I found:

1. Plug wires caps were loose and wires were breaking down - replaced them with MSD's best 8.5 mm wires.

2. Installed fuel gages and found one fuel pump fluctuating - changed both fuel pumps as the one's they had on it turned out to be automotive anyway, no rupture tube (hose) to the carb.

3. One alternator had voltage dropping as low as 12.5 volts, the other one was putting out 13.9 - had them rebuilt installing 14.75 volt internal regulators and both are now 65 amp (one was 55amp the other 65 amp)

4. Finally. Even though the carbs had been "rebuilt", turns out they didn't do anything but change a couple of gaskets and screwed up the float settings in the process. Had them rebuilt by a reputable rebuilder where they test them on an engine and then tell you not to mess with anything but the idle screw. THIS WAS THE CAUSE OF THE RPM's (and engines) SURGING FROM SAY 3000 RPM THEN 3,500 OR VISE VERSA.

The occasional pop through the carb on the top end is gone and the plugs are a nice light tan/brown instead of the white white they had been. Bottom-line; after rebuilding the engines and going through the accessories getting them right, THE DAM THING RUNS LIKE IT SHOULD. The guy(s) that had it before me went way out of their way to screw it up over the years!

Many thanks to you guys for all the thoughts and suggestions, I hope I can return the favor when you get desperate. Based on the threads which I now read on a daily basis, it's not a matter of whether you will ever get desperate with these boats, it's a matter of WHEN! But hey, if it was easy, you'd have girls doing it! Thanks again.

Al

Great news, Al. I guess a lesson here is to never, ever underestimate the ability of some people to totally screw things up.

Bulldog aka BulLfrog

:frog:

alcor,
Glad to hear things finally came together for you!! Now relax and enjoy that thing!!

Dick

Glad to hear you got it running well. :)