Oil Buzzer - '86 Yamaha 90 hp

PenleyFace · #1 July 25th, 2005, 09:30 AM

First post for me. Have read the rules about posting. I'm new to all this and have been reading whatever posts I can find, but most are from folks who actually know how to work on outboards. I'm total greenhorn.

Just had an '86 Yamaha (90 horse) serviced by local mechanic. First time back in the water it idled 5 or 6 minutes and the oil buzzer started going off. However, it ran fine once I got going (half to 3/4 throttle). I assumed that the injector wasn't feeding enough oil at idle so (as my mechanic suggested), I mixed a little (not 50:1) into the fuel as well. Hooked up the rabbit ears for about 15 minutes and it ran fine at idle and at half throttle. However, I put it back in the water this weekend and the buzzer started going off again. It was peeing fine, so I sped up a little and it started knocking heavily. Eased back into the harbor and shut it down.

Any help? I figure the oil injection could be completely fouled up and I know how to disconnect, so I can start mixing the fuel, but could it be something a lot worse? The lower unit doesn't seem to be too hot to the touch and the paint definitely isn't bubbling on the lower unit (as some posts indicate). I'm taking it back in this week but just trying to get an idea of what I could be facing.

Thanks everybody, and sorry if I'm asking the same question for the thousandth time.

penleyface

rodbolt · #2 July 25th, 2005, 08:15 PM

ok the oil alarm and overheat are the same horn. if you have the yamaha digital tach it will have a visual indicate on it. if its oil you will see a red light or a flashing bar or arrow, depending on the year of the tach. the alarm system only monitors tank oil level. has nothing to do with any oil flow anywhere.its imperative to determine if its overheat or oil. next time the horn sounds dissconnect the pink wire at the head while the horn is sounding. if it quits sounding its an overheat alarm. if it contiues its oil level. then you will have a path of troubleshooting.

if my yamaha tech told me the alarm may be a flow problem I would find another yamaha tech.

PenleyFace · #3 July 25th, 2005, 08:49 PM

thanks rod, esp. for answering something you've probably answered a hundred times.

will do the pink wire test tomorrow

I believe the oil problem has been fixed so I'm guessing it'll be an overheat issue, which would probably make it an impeller issue, right?? after reading posts for hours, that seems to be the common denominator for similar circumstances (despite a "tell-tale" water stream).

If it's a bad impeller, does that explain the violent knocking at half throttle? The knocking lasted a few seconds each time (2 or 3 times), so I dropped to trolling speed and limped back to the harbor. Did I cause more damage with this one short outing, or does it take long periods of overheating to destroy the engine? Am taking to tech later this week but am now freakin' out that I might've killed my motor.

thanks to all. this forum is excellent.

pgrace4 · #4 August 13th, 2005, 07:21 PM

this is EXACTLY my problem as well ..... i would love any help