At End of rope: 1992 Evinrude 120

[crestlinermusky]

I have a 1992 Evinrude 120 that has been giving me fuel issues this summer. At the moment I have no WOT. With the throttle all the way she is running hard but half speed
The carbs have been pulled and cleaned,compression checked (130 on all 4)
Timing and stator, coils, new wiring and plugs
Took it out last Friday and it ran great. Tonight a dud. My question is that it still has the original VRO pump that has been deleted
Is it possible that the pump is failing
It starts up right away, it’s when you ask for power that it goes to hell
View attachment IMG_4716.mov

 

[brodmann]

I'd watch a goo video on ceaning the carburetors. Most folks don't purchase carb kits and do it correctly. I'm pretty sure on those carbs you have to knock out some plugs and clean the passages underneath. If you hit the choke, does that make it rev up for a second? The 2 things you need to check are fuel delivery and GOOD spark. You can buy a spark gap tester at auto parts stores for about $10. Make sure all cylinders have a sufficient spark to jump a 7/16" gap. It that's good, you have a fuel delivery problem. Don't understand how it ran good one day and a week later is garbage!

 

[crestlinermusky]

I'd watch a goo video on ceaning the carburetors. Most folks don't purchase carb kits and do it correctly. I'm pretty sure on those carbs you have to knock out some plugs and clean the passages underneath. If you hit the choke, does that make it rev up for a second? The 2 things you need to check are fuel delivery and GOOD spark. You can buy a spark gap tester at auto parts stores for about $10. Make sure all cylinders have a sufficient spark to jump a 7/16" gap. It that's good, you have a fuel delivery problem. Don't understand how it ran good one day and a week later is garbage!

I have been dealing with this issue since June. The motor has good spark, If I rev it up, it revs up, at low speed it is fine, it is when I ask for power. This problem started when i was using the onboard tank in the floor. It is running on a portable tank now. Marine Mechanic cleaned the carbs, he checked everything, the only thing that is left is the fuel pump which is the original VRO pump. It pumps fuel but I wonder if it is pumping enough fuel

 

[ct1762@gmail.com]

I have been dealing with this issue since June. The motor has good spark, If I rev it up, it revs up, at low speed it is fine, it is when I ask for power. This problem started when i was using the onboard tank in the floor. It is running on a portable tank now. Marine Mechanic cleaned the carbs, he checked everything, the only thing that is left is the fuel pump which is the original VRO pump. It pumps fuel but I wonder if it is pumping enough fuel

well i wouldnt say the only thing thats left is the OMS pump. Are you 100% sure there is no water in the fuel? I'd stick your fuel hose in a can of fresh premix to be sure. Pump the bulb when its acting up... any change? thats an easy way to see if your fuel pump is working so no guesswork.
Edit: i see you switched to a portable. still squeeze bulb and see what it does. timer base moving all the way up to its stop? throttle plates all exactly horizontal at WOT? very possible your mechanic pinched a carb gasket. no mention of throttle bodies... did he clean those with fresh o ring gaskets?

 

[crestlinermusky]

well i wouldnt say the only thing thats left is the OMS pump. Are you 100% sure there is no water in the fuel? I'd stick your fuel hose in a can of fresh premix to be sure. Pump the bulb when its acting up... any change? thats an easy way to see if your fuel pump is working so no guesswork.
Edit: i see you switched to a portable. still squeeze bulb and see what it does. timer base moving all the way up to its stop? throttle plates all exactly horizontal at WOT? very possible your mechanic pinched a carb gasket. no mention of throttle bodies... did he clean those with fresh o ring gaskets?

It is new gas,carbs cleaned and new o rings
It ran great last Friday, now it’s starving for fuel. Fuel pump is vacuum operated, maybe a vacuum leak somewhere

 

[ct1762@gmail.com]

It is new gas,carbs cleaned and new o rings
It ran great last Friday, now it’s starving for fuel. Fuel pump is vacuum operated, maybe a vacuum leak somewhere

check the pulse limiter . but i'd now say you have an issue in a carb or 2. its quite easy to pinch a gasket or get something lodged in a passage or orifice. again pump the bulb to rule the pump out.

 

[airshot]

Cleaning a carb is not the same as rebuilding a carb. When I had my Johnson and decided not to use the vro, system, I had to block something off and plug a hose. Don't remember exactly what all I did, but I do remember blocking off and plugging things.