HP 500 running out of fuel above 4000RPM
#11
Platinum Member


fuel starvation - put a pressure gauge on the fuel line at the carb. Have somebody watch it as you run her up. If pressure stays constant, then you look elsewhere.
elsewhere - replace the ignition coil with something you have handy.. It can be a cheapie for this test. If a garden variety $9 coil lets her run up farther, then replace your coil.
You can also have jetting problems, trash in secondary floats, etc.
Hard to tell by listening from here.
MC
elsewhere - replace the ignition coil with something you have handy.. It can be a cheapie for this test. If a garden variety $9 coil lets her run up farther, then replace your coil.
You can also have jetting problems, trash in secondary floats, etc.
Hard to tell by listening from here.
MC
#12
Registered

As mentioned, you need to first narrow the problem down to fuel, ignition, etc.
Install a temporary fuel pressure gauge. That will tell you if it's fuel related. If so, then you can start to narrow it down further.
If the pressure is fine, then it is possible that it is in the ignition system. I doubt it since most ignition problems cause the engine to miss and stutter under load, not just die.
One other thing, it's not really a good plan to keep running it like this and causing it to kill. If it is fuel related, you are seriously leaning out the engine just before it kills. You are asking for trouble by continuously doing that.
If it starts to die and the pressure is staying up, then back off and try to keep it running. Watch the voltmeter carefully and see if it flickers at all. It could indicate a wiring issue.
Good luck.
Eddie
Install a temporary fuel pressure gauge. That will tell you if it's fuel related. If so, then you can start to narrow it down further.
If the pressure is fine, then it is possible that it is in the ignition system. I doubt it since most ignition problems cause the engine to miss and stutter under load, not just die.
One other thing, it's not really a good plan to keep running it like this and causing it to kill. If it is fuel related, you are seriously leaning out the engine just before it kills. You are asking for trouble by continuously doing that.
If it starts to die and the pressure is staying up, then back off and try to keep it running. Watch the voltmeter carefully and see if it flickers at all. It could indicate a wiring issue.
Good luck.
Eddie
#13
Registered

the little screen in the bottom of the pick up tube in the tank. start there. then the anti-siphon valve. replace it with a pipe fitting. if it works, get a way bigger anti siphon...