RPM issues F4MSH

[STO-Becky]

When the engine is cold it starts easily, with no choke, runs at full RPM. After it warms up it will only go up 1/2 RPMs at full throttle. It acts like the choke is stuck, but visually you can see it is fully open. Any ideas as to what will cause this and what we can do about it?

Rick

Model F4MSH
Seriel 1092673 It is an 2008 model.

[99yam40]

How are you measuring the RPMs and what RPMs are you getting?

what does your service manual give for the WOT timing and is it getting to that spec?

If compression, spark , and timing are good then you are left with fuel problems.
fuel pump leaking into crankcase or float not closing off as it should or set wrong can flood motor.
Normally it is starving for fuel due to plugged passages/jets that cause problems

[STO-Becky]

Thanks, I will have the mechanic check the fuel problems.
Rick