1993 Yamaha ProV 150

[Ed Reichert]

My Yamaha goes into the limp mode when it exceeds 5000 rpm.
I've changed the impeller,pressure plate,O rings,poppit valve,thermostats,checked the thermo switches.
I was thinking about buying a new waterpump housing,and thermo switches.
Any advice you could give me on fixing my problem would be appreciated.Also I checked the oil pump to see if it was pumping into the resevoir fast enough.

[99yam40]

measure the temp on the heads/ block around where the temp switches are located to find out where the hot spots are.
May have to clean passages if pump housing is not the problem

[jb123]

i would suggest to run it and have someone watch water level over cav plate,maybe losing flow over intake

[Ed Reichert]

Ive heard that I could pour vinegar through the thermostat housings,then flush the system that it might clean any blockages. Is that true?




Ed

[almetelo]

Some guys say vinager works other don't... Try it is my sugestion (is cheap) and share your results with us...

I guess the most apropriate (or most known/popular) liquid to clean motor passages are:

SaltAway and Neutra Salt

Good luck

[BQUICK]

The latest I've heard that "works" is to use dishwasher detergent gel (the kind that claims to remove hard water deposits). Remove themostat with motor tilted and pour a good amount in. Let sit for 30 min. Put in water and run it.
I haven't tried it so use at your own risk. No warranty expressed or impied.

SaltAway IMO is better at prevention than removal of heavy deposits.

[99yam40]

read good things about this, but have not tried it myself
Apex - RYDLYME Marine is a safe, biodegradable, non-toxic, non-corrosive marine descaler. RYDLYME Marine is designed to dissolve the toughest water scale, lime deposits and rust deposits.

[Ed Reichert]

93 yamaha proV 150

Thanks guys; I'll take your advice.Ed

[rodbolt17]

when your done with snake oils.
pull the heads and water covers,clean the scale, reassemble.