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buffskier
09-13-2012, 06:34 PM
I was on a couple of weeks ago with an impeller issue which I have now solved. Chunks of impeller were back by the tranny cooler and either blocked water or ground up the impeller. HAve since solved that problem, but now I have an odd power loss. The boat ran very hot for about 2-3 minutes when the impeller first failed before I caught the steam and v high temp guage reading.

After fixing impeller, I get a complete loss of power at 2400rpm (about 20mph). I can hold it at 2400 rpm all day but any increase in throttle above that causes a complete bog down of the motor and it drops to idle and dies. This happens only under load. In neutral it will rev up just fine. It starts immediately on the key turn.

I have replaced the fuel filter, points, and plugs to no avail. A mechanic rebuilt the carb as his theory was that old fuel had gummed up things. He checked teh pump and tells me it is fine. (It sat idle for a year with Stabil in the tank) This is starting to get pricey now.

Any thoughts would be much appreciated.

Cheers

j.mccreight@hotmail.com
09-13-2012, 11:32 PM
Sounds like the secondary on the carb is not opening. I would double check the carb, might have melted the diaphram when it overheated...

petermegan
09-14-2012, 05:30 AM
It sounds like a lack of fuel to me. Have these holley carbs got a small bronze sieve in the inlet like the car ones did/do? Are you sure fuel pump and filter are ok. Next would be to check the secondaries as mentioned above. Have fun.

TRBenj
09-14-2012, 08:27 AM
The secondaries should not be coming in anywhere near 2400rpm, I highly doubt that has anything to do with the issue being described.

Sounds like youre running out of gas at higher speeds... which would indicate a fuel delivery problem.

03geetee
09-15-2012, 07:50 AM
Power Valve blow?

JTR

thatsmrmastercraft
09-15-2012, 10:45 AM
Power Valve blow?

JTR

Nope. If the power valve diaphragm ruptures, it goes to full rich and runs fat and blows smoke. If you could get it up to speed it would eventually run fine, but can't get there.

03geetee
09-17-2012, 06:45 PM
Nope. If the power valve diaphragm ruptures, it goes to full rich and runs fat and blows smoke. If you could get it up to speed it would eventually run fine, but can't get there.

I wouldnt even think to argue such an educated individual like your self Peter, nice call!

JTR