Where do you like to connect gauge? Proper pressure range? Will gauge pulsate? I have a rough idle in gear and engine will not run above 3500-4000 rpm.
Manual fuel pump? Not following. If your referring to the primerbulb, same.
118, 118, 115 last year before winterizing. No real change in 20 years.
Never tried. Is this at idle? DVA voltage to coils is normal at idle
Thx.
If operation does not improve when you operate the manual fuel pump then you do not have a fuel pressure issue.----More trouble shooting is required.----Sounds like motor is only running on 2 of 3 cylinders.
Trying to get someone out there with me on a calm day so I can take some DVA readings at speed. Are you referring to the primer bulb when you say manual fuel pump?
The primer bulb is nothing but a manual pump.----It moves fuel.----And most able bodied folks can generate much more pressure by hand then the PRESSURE fuel pump on your motor.----Elegantly simple testing can be done.
I had exactly similar symptoms on my 1991 90hp; rough idle and would only run at 4000 RPM max. I did a bunch of fuel and electricity related tests and even changed switchbox with no help.
DVA tests (which I don't recall having done while driving but on the hose) led me to buy a new trigger off an outboard salvage yard. I also discovered that two out of three of my ignition coils had cracked ferrite cores inside them. The coils are easy to inspect so I would suggest you check those out. They might crack easily when handled so caution is needed.
Changing the trigger and all three coils solved my problem and the engine ran perfectly at 5500-5600 WOT after that.
Thanks for the advice. I plan on DVA reading again on the hose, then on the lake. I am suspicious of the coils and took a good look at them and meter readings. My brother has same coils packs in his low hour V-6, perhaps he will let me try them. I did replace the 32 year old plug wires, no help.
Trying to get someone out there with me on a calm day so I can take some DVA readings at speed. Are you referring to the primer bulb when you say manual fuel pump?
Found my problem late summer. #2 high speed jet was plugged with white stuff, looked like calcium. Cleaned jet, checked the other two, and all is back to normal. This boat and motor are my off season, cold water ride. Summer months are for the skiboat.
