1986 115 Evinrude V4 - Power Loss at High Speed

[Jusduky]

I appreciate all the suggestions. I did talk to a local mechanic and he suggested I retest with another fuel line and bulb. When I was squeezing the bulb it just didn't get firm like I know it should. I decided to remove the remote tank fill cap and low and behold the bulb got firm with only a few squeezes. Evidently not enough air was getting into the tank to allow a consistent fuel line pressure.

I took it for a ride and it never lost power at high speed.

I am still struggling with getting the motor to take off from a stop position until the motor has been run once at high speed. I end up pumping the throttle to try to get to top speed with out it staling.

Would it make any sense to adjust the idle speed up a little? Thanks in advance for all your help,
Brad









I have been fighting this problem for a couple weeks. I have ruled out any fuel line issues from the external tank and the motor. The symptoms are amazingly consistent. I get the engine started and warm it up then try to go at high speed. It usually takes several attempts. It stalls consistently if I hit the throttle to WOT. If I nudge the throttle up I can finally get it to go and once planed out I have about 13-15 seconds of high speed and the motor just shuts down like somebody turned the fuel supply off. It stalls, then I restart and nudge it to full speed and it may go about 7 seconds before almost totally stalling again. At this point it actually just drops to idle speed and then I can start off again and get it up to high speed and again it will drop off to idle speed again after about 7-10 seconds. What do you suggest I do next

I have changed plugs, no change and sprayed the carb with cleaner and no change.

What do I do next??? Thanks, Brad

[Daviet]

Compression and spark ok?
It sounds like it is time to disassemble and clean the carbs paying attention to the high speed orifices.

[jayyyy]

I had a 1983 115hp johnson that did the same thing. Turned out to be the fuel pump.

[emdsapmgr]

You may want to check your model number for the correct year/hp. OMC did not make a 115 engine in 1986. Try constantly priming the fuel hose bulb when you have problems. If the engine runs any better, have a hard look at the fuel pump. The inability to accellerate may indicate the midrange jets are restricted.