1990 omc cobra 4.3 won’t rev above 2500

[Boots287]

Hello, I am work on a1990 omc cobra with a 4.3 and it starts up and idles fine but will not rev above 2500 rpm in neutral and under load. I have put new points and condenser, cap, rotor, spark plugs, plug wires, and have a new coil. Firing order is correct and timing is at 8 degrees btdc. Any help will be greatly appreciated.

 

[alldodge]

Howdy
Is your Tach accurate?
Can the boat get on plane?

 

[Scott Danforth]

compression test numbers?
did you set the dwell with a meter?
fuel pressure?

 

[Lou C]

Check fuel delivery system
Pump, tank vent & anti siphon valve and of course carb
Ignition system
Dwell, total timing advance at 3200 rpm (18* for the pre vortec 4.3 V6)
Base timing should be 6* BTDC
Spark plugs (AC 43MR marine plugs)
Gap .035”

 

[Boots287]

thank you for the responses fuel pressure is at 6psi. It will not rev up in neutral or in gear. I do not have a dwell meter. Mechanical advance moves freely

 

[alldodge]

Compression test
My guess is the motor is just wore out, because it should rev easy in neutral

 

[Lou C]

So pump is ok but you still have a lot to check. If you have a boat with the points distributor you really should have a dwell meter. I set mine at the lower end of the dwell range because dwell & gap are inversely related. So lower dwell equates with larger gap and the points will stay in adjustment longer. I usually get 4-5 seasons out of a set.

 

[alldodge]

thank you for the responses fuel pressure is at 6psi. It will not rev up in neutral or in gear. I do not have a dwell meter. Mechanical advance moves freely

Wait, when the throttle is moved does it move the carb linkage?

 

[Lou C]

Good point Is the throttle valve in the carb opening following the throttle lever opening?
I had a similar but not identical problem years ago and it was the anti siphon valve on the gas tank. Mine would rev in neutral but would not plane out the boat.

 

[Boots287]

So the compression is at 150 on all cylinders. The carb is working, at wot butterflies are open and it’s getting fuel. I will try a little wider cap on the point and hopefully that will change something. Last year I had no issues just this year. It starts right up but it will not make power

 

[alldodge]

Something is missing, things don't add up
Carb motor, throttle plate opens wide
6 psi fuel pressure
Compression at 150 all cylinders (hope this is about 150 because otherwise its BS)

 

[Scott Danforth]

Check dwell with a meter. Only thing left

 

[Boots287]

Got it figured out I was floating the points. I installed the the spring wrong on the points and now it does what it is supposedly to do