Yamaha 115 problem

[yamaha fan]

I have a Yamaha 115. Runs great when cold (i.e. 5500RPM) but after idling or *****ing for a while drops to 4800 RPM or less depending on how long idling lasts.....the longer, the lower the RPM.

If engine is turned off during a long drift it perks back up to normal.

Any thoughts?

[boater21]

I have same problem with my 70hp yamaha. So hopefully someone can help I changed plugs seemed to help a bit but did it again.

[yamaha fan]

115 follow up

I changes plugs
Had injectors cleaned
replaced thermostat

Each step helped the engine run better.....but only when cold. Went right back to low rpm's after idling for awhile

[boats.net]

If this is a four stroke model then have it checked on computer diagnostic, run a compression test.

[yamaha fan]

115 followup

It is a 4 stoke and performed compression test was OK.

Any other thoughts?

Thanks

[boats.net]

Check fuel pressure and fuel vacumn test to see if starving for fuel.

[markgabrielli]

you could be losing a coil,try using a timing light to see if one is dropping out.

[gerront]

Im having almost the same problem. Havent fixed mine yet, but a coil could be going out and failing as it gets warmer and warmer.... Mine started doing it while *****ing one day.....lmk what you find out...good luck to ya!

[yamaha fan]

Will be playing with my mechanic next week.....will let you know if we fix

Thanks for all ideas