Overheating 1996 Yam 250 & Saltaway

[Freespirit]

MY 96 Yam 250 cooling system was overhauled two months ago by a dealer including servicing the poppet valve. The other day the buzzer went off after running at 4500rpm for an hour in clean deep water. I fished for awhile and let the motor cool. ON the way back home, the buzzer sounded in a half a minute every time the motor exceeding 4000 rpms. I put it in reverse and the buzzer would go off in about 20 seconds. After repeating this a few times, I limped home at 1500 rpms not wanting to cause any damage.

Since the cooling system was recently serviced, I was going to try using saltaway and flushing the engine. Boat is in the water. Can I tilt the motor up and use muffs and run it and flush with Saltaway?

Any other suggestions? I was going to remove and inspect the thermostats too.

Thanks

 

[bowhuntrrl]

Re: Overheating 1996 Yam 250 & Saltaway

Check the poppet valves. I've seen them installed backwards. Yamaha came out with a different style from the originals that seems to work better.

 

[rodbolt]

Re: Overheating 1996 Yam 250 & Saltaway

are you positive it was an overheat horn and not an oil alarm? you just described the symptoms of a clogged oil filter in the remote tank.
you can try the salt away but I have never seen it actually work.
on a yamaha we dont normally see issues above 1000 RPM with the poppit valve.
after checking everything it may be time to pull the heads. I have seen the pencil zincs break off inside the block and impede water flow
someplace there is a tech bulliten on T-stat housings on 3.1L motors but I cant remember what years are applicable.

 

[Freespirit]

Re: Overheating 1996 Yam 250 & Saltaway

Thanks Rodbolt for the reply. I have no idea if it's the oil alarm. How can I tell? What makes you think the symptoms point to that? Where is the oil filter located on the remote tank and how do I clean it?

 

[rodbolt]

Re: Overheating 1996 Yam 250 & Saltaway

on the digital tach there is a visual for low engine oil. will be lights,arrows or bars depending on the tach. Yamaha uses the sme horn for both low oil and overheat, the difference is the visual indicates.
the remote filter is located on the lower back side of the tank between the pump and the outlet nipple. if it cloggs then oil flow is restricted and the engine can burn oil faster than it can transfer.
as soon as the horn sounds and you slow the engine RPM now oil can flow faster than its being consumed as the tank fills the horn quits. then 10 min later the process repeats itself.
thats why I ask are you sure its overheat and not low engine tank level.

 

[Freespirit]

Re: Overheating 1996 Yam 250 & Saltaway

I'll check that out. Can I run the motor in tilted position with muffs on?