50 Hp RPMs

[jeff@eddracing.net]

I have a 1985 Yamaha 50hp outboard that will only go 4000 rpm in nuetrial I can tack it out over 6000 rpm. It will run great after I clean the carbs. when I get out on the water after the cleaning it wil run 5200 rpm for about a half hour then cuts back to 4000 rpm. I run seafoam and new gas and still does it. What am I missing here?

Thank You

[99yam40]

You may have trash or water in the fuel tank, lines, pump carbs.etc. or bad fuel.
You should not rev the motor in neutral without a load, some motors have rev limiters but I do not think yours does.
You need to clean the carbs and the rest of the system real good and adjust according to the manual.

[jeff@eddracing.net]

I'm running a brand new water seperator. drained all the fuel into my truck refueled empty tank on my way to the lake and same thing 5200 then 4000. the only thing I haven't cleaned is the fuel pump. No I don't have a rev limiter.

[99yam40]

If it ran good after cleaning carbs then I would say you need to do it again.