1999 Yamaha F50 four stroke idles fine runs rough above 2,300 rpm

[Gusmiller1]

I was coming back across the lake running about 5000 rpm when the motor sputtered like it was running out of fuel I dropped back to idle and checked the tank it was full, as soon as I started to accelerate and get up around 2,300 rpms it would start to run rough and maybe reach 3,100 or 3,200 rpms.
The motor starts and idles fine it just won?t run smooth above 2,300 rpms.
I have done the following

1. Switched spark plugs
2. Cleaned fuel filter
3. Run a 50/50 mix of gas and Sea Foam to clean the carbs

I also disabled one coil at a time and there was no difference in idle between the top coil and bottom coil.
Any suggestions would be greatly appreciated; the only thing is the motor is in Michigan so I won?t be able to run the motor until spring.
Thanks
Gus

 

[hondam]

Its probably a fuel problem, carbs need be be cleaned. A vacuummate is required to do this job properly so you will probably need to take it in.

Seafoam is not a fix-all.

 

[tommarvin]

Where to start,clean the carbs,take the bowl off, take out the idle jet and high speed jet and clean all the small holes.

When old ignition parts get hot/overheat weird things like this,and they have to cool for awhile to work normal again.

You are correct, test coils first, do you have spark jumping 1/2 inch on a spark checker on all cylinders? test all ignition/power packs, test trigger, test stator.

Cdi electronics.com has all the parts and info on testing coils,power packs, triggers,stators. rectifiers,, fill in your motor info, the parts and trouble shooting info will tell you what to do. please tell us what the problem was,so we can learn something.