Re: yamaha 2001 115 efi making oil
compression test on that motor is about useless.
we need a leakdown test.
what is max RPM running with your normal load?
when was the last time the thermostat was checked or replaced?.
there is also a tech bulliten that covers a range of seriel numbers in about your production year model.
go by any yamaha dealer and have them run your PID.
your looking for possibly 2 tech bullitens.
one on making oil and one on the oil pump(totally seperate but have a look).