Help, HP500s won't stay running...
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I really need some troubleshooting help here. I had an engine rebuilt this year and everything was running fine 2 weeks ago. We were out the whole weekend and everytime (even the first start on Friday night) the boat fired right up with no problems whatsoever. Then a week ago Friday, we went to start it and the first engine fired right up, ran for maybe 15-20 seconds and died. The other one would then fire and run for a couple seconds and quit. The carbs were squirting gas when the throttle was pumped. After trying for 20 minutes or so, we gave up when it didn't even seem to be close to firing. I had a friend on the phone who suggested jumping the + from the battery to the + on the coil and still nothing. What's baffleing is that it's happening with both engines, which would seem to rule out fuel pumps, filters, ignitions, and any other system that they don't share.
Any ideas out there? It would seem to be fuel and/or electrical, but somewhere where the 2 systems would affect both engines. We had to leave on vacation the day after it happened so I haven't looked at it for a week. I'm picking it up tomorrow and bringing it home to check it out, but any advice would be great at this point...
Oops, little more info if needed - 95 Formula 336...
Any ideas out there? It would seem to be fuel and/or electrical, but somewhere where the 2 systems would affect both engines. We had to leave on vacation the day after it happened so I haven't looked at it for a week. I'm picking it up tomorrow and bringing it home to check it out, but any advice would be great at this point...
Oops, little more info if needed - 95 Formula 336...
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I had an odd problem last year, with time running and motion, my starboard motor would die. sit a few and run, and die again. Turns out had a corroded connection on the harness quick connect at the motor. This was after a new coil, swapping carbs and testing everything, along with crawling into river with a single screw in a strong current... Not thats its your issue but does sound like an electrical issue some where. Is it a bad common ground?
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Chris G.
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Last edited by CMG; 07-04-2004 at 10:12 PM.
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Bill, I agree it would seem to be electrical, but... did you by chance fill the tank between the time it was running well and the time you started having problems? If you got a load of bad gas it could be causing problems for both motors. More likely it is electrical, but...
Remember Occam's Razor.
Remember Occam's Razor.
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Ok, I took the boat to a shop the week that I posted this. They looked at it for a while and found that the spark was good and the fuel pumps were working fine. They hooked up an external tank and pressurized the fuel line and the carbs would not take any gas. The guy then tapped on the carb float adjustment screws and bam, she started right up. It worked great for the rest of the weekend, firing up with a touch of the keys. The following Friday, I go to start the boat and it fires, runs for 10 seconds and quits. I tap the float screws, and it runs great all weekend. Last weekend, one fires right up, the other still needs the tap. I just filled the tank again (I took on 100 gals two weeks ago, 133 today), so if it was bad gas, I think I'd be in the clear now. Should I add some carb cleaner to the gas to free up the floats that seem to keep sticking?
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I'll probably do that at the end of the season. Carbs are voodoo to me, and I don't want to risk f'ing something up and losing one of the remaining weekends in our short season. It's kind of an odd problem. The floats seem to be stuck high, but only after sitting for 4 or 5 days. The mechanic said he'd never seen anything like it, where all 4 floats were stuck at the same time.