1984 johnson 115 questions.

[JoshKeller]

finally got the breakin period over with the 115 we rebuilt for my buddies boat. Took it out today, an it ran great for 5 miles or so. Went on a long straight away and it missed a few times, then wouldnt stay on plane. Fished for a little while, then went back to head to another spot. Motor is a rocket out of the hole until it hits 2500 rpm, then wont go above that. Never really dies off or surges, just wont go above 2500. had two spare powerpacks that I know are good in my tool bag, and it made no difference. Motor idles well . After we loaded onto the trailer an went back to the garage, Replaced spark plugs with new champions ql77jc4. I pulled each plug wire off one at a time while motor was running on the hose. All made a difference, but the bottom two were less of a difference than the top two. Pull the carbs off and cleaned them, put back together, and no difference there. The motor will actually start and poorly run on one cylinder for all 4 cylinders.

Took a compression test, and all cylinders are at 103 - 105 psi. Motor is charging the battery. No fuel leaks. Idle rpm is the exact same as it was before, and we idled it on the hose for an hour with absolutely no stalls, sputters, or coughts, etc.

I have video of the motor running in the water, but cannot get it to upload to youtube via my phone.

any other suggestions?

[EMDSAPMGR]

Check the spark on each plugwire after the engine is fully warmed up. Weak ignition components tend to fail once the engine heats up to normal operating temps. The factory service manual should have voltage checks for both the stator and timer base.

[tony1204au]

I would have a closer look/test the stator... I had one of those that would come out of the hole just fine, but couldnt get past 3200 rpm..
Replaced the stator and up to 5600 she went... I dont think these stators have high and low sides like a merc, but you may have a weak stator..

[Scmarineperformance]

stator heating up could do it if its breaking down. as well as you might want to check into the fuel delivery system to the engine my golden rule is to always use a portable 6 gallon tank for testing . and check the fuel pump output.

[JoshKeller]

here is a video of the motor not getting above 2500 rpm. http://www.youtube.com/watch?v=_rFIQx7XlYg&feature=youtu.be