2002 Johnson 115 running rich and stalling, no high RPMs under load

d.glennon

Recruit
Joined
Dec 5, 2016
Messages
1
Hi Guys,
I have posted about this a few times and I?m almost at my wits end with this motor. Below you can see everything I?ve done with the motor, the carb work and gaskets being most recent. Dropped the boat in the water this past weekend and had no success, the motor still stalls out and will not run at high RPMs at all while under load. I took the upper cowling off to find gas in my engine compartment, took the air silencer off (#52) and revved the boat up in neutral to see what was going on. All four carbs are spitting out fuel when revved up to the point where it filled the bottom of the silencer with fuel. The top left carb seemed to be the worst and was firing smoke out of the mouth of the carb when revved up. This leads me to believe the motor is getting way too much fuel. Ran the motor with an external tank as well as off the internal set up, no difference.

I have contacted the distributor we got the VRO fuel pump from, they are not able to replace it. At $450 I have tried to rule out everything before pulling the trigger on that VRO replacement. Does anyone have any other suggestions? I understand there are ways of testing the pump using a clear hose filled with oil etc. but I have not gone through that yet as it appears the motor is getting too much fuel. Additionally I know that when the pulse limiter line is removed and the ball is pumped the VRO does not release fuel which is a good thing. When I had the intake apart there was fuel sitting in the crankcase with the pistons and the exhaust leaks out the excess raw fuel as it sits on the trailer at the house.
At this point I am stuck between bringing it to the mechanic or purchasing the new pump as that?s all I see left that could possibly be causing the issue. Any thoughts or ideas are appreciated. Thank you!

Replaced so far:
? Intake manifold gaskets (man. To head and man. To carbs)
? All carburetor gaskets (carb repair kits on all four)
? Jets, floats, seals, seats
? Essentially all gaskets in the fuel intake and carbs.
? New fuel line
? New fuel ball
? New racor fuel filter/water separator
? New fuel line fittings
? New fuel tank pickup
? New spark plugs
? Tested for spark and compression
? Fuel pump replaced 9 months ago, just got my hands on the boat from my dad, boat did not run prior to installing the new pump and has not run property with the new pump.
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Chris1956

Supreme Mariner
Joined
Mar 25, 2004
Messages
27,036
Gee, I assume you have the correct OMS pump? If so, it would be surprising to see it overpower the carb inlet needles, allowing the carbs to flood. Are the carb floats set to specification? I would recheck those, as you cannot fix anything else with the carbs flooding.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Not much on your list would solve the problem of blowing fuel out of the carbs. The VRO (OMS) pump wouldn't have anything to do with it.

Reed valves

Needles and floats

Bad blow by on the rings

Carb not assembled correctly.

Primer either failing or the lever is in the manual position.
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
When you squeeze the primer bulb does it get hard and stay that way for a few minutes (when the motors not running)?
 

Baylinerchuck

Commander
Joined
Jul 29, 2016
Messages
2,726
Agree with float height, float valve and seat and generally carb issues, or the motor being unable to draw in the full charge of fuel due to what ondarvr stated. Does fuel drip out the carb throats when pressing the squeeze bulb? I'll second the primer lever, definitely look there.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
VRO pumps are not well understood.----Most are replaced as a guess.-- I would test the VRO pump.------I would take one of those pumps apart for inspection before spending $ on a new pump.-----Opinions will vary if money is not a problem !
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
A quick and easy test is to just bypass the the pump. Put some pre-mix in a small tank and run the hose directly to the carb, use the squeeze bulb as the pump.

This will let you know if the pump has anything to do with the problem.
 
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