Hp 500 carb setup help
09-04-2014, 08:21 AM
#31
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I'm wondering why the original carb(s) where replaced.....
Wouldn't happen to be the same issues you are having now, would they ?
Wouldn't happen to be the same issues you are having now, would they ?
09-04-2014, 09:17 AM
#32
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Sounds to me like you have another issue. Whether it be a bad fuel pump, clogged filter, or an ignition problem. My guess is the new 850 carb was purchased in an attempt to fix that problem?
Starting with throwing a mechanical fuel pressure gauge on it, would be a good thing. Watch for drop in fuel pressure. If fuel pressure holds steady, I'd start looking at the ignition system.
Starting with throwing a mechanical fuel pressure gauge on it, would be a good thing. Watch for drop in fuel pressure. If fuel pressure holds steady, I'd start looking at the ignition system.
09-04-2014, 10:10 AM
#33
Gold Member
i couldnt figure out the other carb it was dumping fuel in at idle. the surge is new...just started few days ago. have stock ign that comes with 99 hp500 new plugs wires cap rotor coil etc. someone was chasing a problem on this motor before me. with my luck its not so simple as the fuel filter but well see.
09-04-2014, 10:20 AM
#34
Did you try switching carbs? Do you still have the original HP500 carb? I would try taking the carb off the good motor and install it on the one having trouble, then put the original carb back on the good motor. That will rule out the carb if no change. Often issues like surging and stumbles are thought to be fuel/carb issues, and end up being ignition problems in the end.
09-04-2014, 10:54 AM
#36
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Compression test and fuel psi test are always 1st when chasing a driveability issue !
09-05-2014, 06:44 AM
#39
Changed fuel filter and restest no change. Going to get some fuel pressure guages, and swap the carbs tomorrow. The boat gets on plane perfectly, then about 30 seconds later cruising at 3300 it starts. Its like clockwork, drops 200 rpm, gains it back 30 seconds later and continues. once i get fuel psi gauges in and swap carbs ill be able to rule out some more hopefully. This is driving me nuts!
