Disparate and out of ideas!!!!!!!!!
08-22-2003 | 07:58 PM
#21
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Joined: May 2003
Posts: 28
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From: Toms River, NJ
Originally posted by alcor
Hey Jersey Tom, let me know if you find anything in the meantime, sounds like we definitely have the same problem.
Al [/B]
Hey Jersey Tom, let me know if you find anything in the meantime, sounds like we definitely have the same problem.
Al [/B]
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.
08-23-2003 | 08:42 PM
#22
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From: Kenner, La.
Originally posted by Jersey Tom
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.
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.
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
08-23-2003 | 08:45 PM
#23
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From: Kenner, La.
Originally posted by h2owarrior
This will sound crazy, but I had a 290 PQ that I had a similar issue with. It just did not seem to have any power and was also sooting the transom. After checking everything I knew to check, someone suggested I look at the battery and battery switch connections. I thought the guy was crazy as the batteries were charged fully and the volt meter showed 13.6 volts.
So I checked the connection and they were tight, but not real tight. So I cranked them down.....on the battery, battery switch. Problem went away.
It may be worth a try.....it costs nothing and only takes a minute or two
It always started fine and idled great....just had no power.
This will sound crazy, but I had a 290 PQ that I had a similar issue with. It just did not seem to have any power and was also sooting the transom. After checking everything I knew to check, someone suggested I look at the battery and battery switch connections. I thought the guy was crazy as the batteries were charged fully and the volt meter showed 13.6 volts.
So I checked the connection and they were tight, but not real tight. So I cranked them down.....on the battery, battery switch. Problem went away.
It may be worth a try.....it costs nothing and only takes a minute or two
It always started fine and idled great....just had no power.
Al
08-23-2003 | 09:36 PM
#24
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From: Toms River, NJ
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.
08-24-2003 | 12:20 AM
#25
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From: Kenner, La.
Originally posted by Jersey Tom
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.
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.
Al
09-02-2003 | 09:43 PM
#26
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From: Kenner, La.
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
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
