Need Help, old 502 EFI only 4950 RPM, rev Limit ?
05-29-2011, 01:25 PM
#1
Registered
Thread Starter
Need Help, old 502 EFI only 4950 RPM, rev Limit ?
I have a 28" Scarab with twin 502 EFI (1993)
Everything are stock only i switched from the mechanical Fuelpump to the elektrical low pressure Fuel pump from the 496HO (861155a6).
I have 3 Set Bravo One Props, all stock no lab.
28" @ 4450 PRM
26" @ 4950 RPM
24" @ 4950 RPM
Is the rev limit in my model year are at 4950 rpm ore can it be a fuel propblem ??
I think i can turn the 26" higher, but something stops the engine at 4950 RPM. I have at this RPM the feeling the engine torns off and than on, like a limiter. What can i do to test it, whats wrong with the engines.
I have read all what the search brings with " 502 EFI rev limit 4950 RPM Fuel ....." Need some idears and help.
Can it be a Problem with VST ??
Can i switch from the VST to the high Pressure Fuelpump from the next model years ? Only the Pump noth the cool fuel, i have no place for it.
Everything are stock only i switched from the mechanical Fuelpump to the elektrical low pressure Fuel pump from the 496HO (861155a6).
I have 3 Set Bravo One Props, all stock no lab.
28" @ 4450 PRM
26" @ 4950 RPM
24" @ 4950 RPM
Is the rev limit in my model year are at 4950 rpm ore can it be a fuel propblem ??
I think i can turn the 26" higher, but something stops the engine at 4950 RPM. I have at this RPM the feeling the engine torns off and than on, like a limiter. What can i do to test it, whats wrong with the engines.
I have read all what the search brings with " 502 EFI rev limit 4950 RPM Fuel ....." Need some idears and help.
Can it be a Problem with VST ??
Can i switch from the VST to the high Pressure Fuelpump from the next model years ? Only the Pump noth the cool fuel, i have no place for it.
05-29-2011, 04:12 PM
#2
Registered
I believe the limiter is 5050 rpm in that engine. It could easily be making that rpm and your tach is just off a little. I would say that's what going on. Most analog tachs are not that accurate.
Eddie
Eddie
05-29-2011, 05:55 PM
#3
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Thread Starter
I have new Monster AutoMeter and a DataTach. I have used a timinglightgun with digital RPM Display, all shows 4950 RPM most time. Also last year i have record ist with Datatach and on laptop with Rinda Diacom.
05-30-2011, 07:15 AM
#4
Registered
Thread Starter
Today have have test a 27" Mirage Lab 4600-4700 RPM.
Than the 28" Bravo one 4400-4500.
Both at the same Speed and both had the on off Problem.
I think its are the new elektrical fuel Pump, i order 2 new mech. Pumps and test the 27" Mirage lab again.
Than the 28" Bravo one 4400-4500.
Both at the same Speed and both had the on off Problem.
I think its are the new elektrical fuel Pump, i order 2 new mech. Pumps and test the 27" Mirage lab again.
06-05-2011, 08:29 AM
#5
Registered
Thread Starter
It was the elektrical Fuel Pump.
The 861155A3 dont work for the 502 EFI.
I have now all stock.
Whit this setup i have test the props again.
Base Time 8°
26" 4950 but slower mph
28" 4250 slower mph
Base Time 11°
26" ?? not testet
28" 4350 faster 4kmh
I think the engine runs to rich, so it slows down the RPM and Power. With the electric Fuel Pump the engine runs to leen befor the fuel stops, but the engine had make RPM and Power befor the fuel stops.
Have anybody test the EFI Upgreat Kit from Hardin Marine ore Keith Eickert....... ECM reprogram, K&N, adjustable fuel regulator ????
The 861155A3 dont work for the 502 EFI.
I have now all stock.
Whit this setup i have test the props again.
Base Time 8°
26" 4950 but slower mph
28" 4250 slower mph
Base Time 11°
26" ?? not testet
28" 4350 faster 4kmh
I think the engine runs to rich, so it slows down the RPM and Power. With the electric Fuel Pump the engine runs to leen befor the fuel stops, but the engine had make RPM and Power befor the fuel stops.
Have anybody test the EFI Upgreat Kit from Hardin Marine ore Keith Eickert....... ECM reprogram, K&N, adjustable fuel regulator ????
