Here's the story... 1995 70HP Johnson that sat for almost 5 years. Emptied the gas tank, added new fuel lines, rebuilt the carbs, new water pump, new plugs, changed the inline fuel filter. Compression checks out at 128-126-127.
After some intial problem which have been solved, the motor idles and runs great throughout the exceleration range. However soon after getting over 5000 RPMs it will run great for a few seconds and then begin to surge and stumble. The higher I go in the RPM range the worse it gets. Eventually if I throttle up and back off it will settle in and run almost perfectly up to about 5000-5200 RPM's. After that if I throttle up again after a few seconds it will start to surge and stumple again. It seems like it wants to go but just wont break thru. It will jump up to 6000 RPMs for a few seconds and then drop back to 4500-5000 and back and forth.
The ball stays hard. I'm on my second new tank of gas. I tried it on a portable tank to eliminate tank vent or pick up tube problems and it did the same thing. I'm contemplating the fuel/VRO pump but don't want to go down that road until I'm sure because they're not cheap. Besides it almost seems to inconsistent a problem to be that. One note, it almost seems to be worse when I'm cornering or bouncing but I'm not really positive about that.
Any suggestion??
After some intial problem which have been solved, the motor idles and runs great throughout the exceleration range. However soon after getting over 5000 RPMs it will run great for a few seconds and then begin to surge and stumble. The higher I go in the RPM range the worse it gets. Eventually if I throttle up and back off it will settle in and run almost perfectly up to about 5000-5200 RPM's. After that if I throttle up again after a few seconds it will start to surge and stumple again. It seems like it wants to go but just wont break thru. It will jump up to 6000 RPMs for a few seconds and then drop back to 4500-5000 and back and forth.
The ball stays hard. I'm on my second new tank of gas. I tried it on a portable tank to eliminate tank vent or pick up tube problems and it did the same thing. I'm contemplating the fuel/VRO pump but don't want to go down that road until I'm sure because they're not cheap. Besides it almost seems to inconsistent a problem to be that. One note, it almost seems to be worse when I'm cornering or bouncing but I'm not really positive about that.
Any suggestion??
