Blew up my Yamaha today

bbh57 · #1 12-03-2014, 09:32 PM

My daughter had my boat out today and the motor oil tank went dry. Not sure why the pump didn't work from the lower tank or why the buzzer didn't go off.

I stopped pulling plugs when I found a bad cylinder, Do you guys think the crank will be shot? Its not locked up.

Its an 98 250 Yamaha 2 stroke, and although it didn't have a lot of hours it may not make sense to rebuild it.

Old'sCool · #2 12-04-2014, 05:38 AM

There's a small, inline filter from the main tank that plugs easily that can prevent oil passing. A low engine tank should sound an alarm though.

Islandtrader · #3 12-04-2014, 09:11 AM

Normally after things cool down you can turn it over again...but if you can't that is a whole other story.

I am sure some of the guys will chime in...you are not the first...Sorry

doodlebug · #4 12-04-2014, 10:27 PM

I'll bet your crank is still good. Needle bearings usually go long before the crank
And pistons scuff cylinders way before that. Question is will your
powerhead come off the exhaust housing.

pelican · #5 12-06-2014, 08:41 AM

Quote:

Originally Posted by bbh57

My daughter had my boat out today and the motor oil tank went dry. Not sure why the pump didn't work from the lower tank or why the buzzer didn't go off.

I stopped pulling plugs when I found a bad cylinder, Do you guys think the crank will be shot? Its not locked up.

Its an 98 250 Yamaha 2 stroke, and although it didn't have a lot of hours it may not make sense to rebuild it.

those alarms - when key is turned to the "on" position,the alarm should sound - if not,check it out and find out why....

few things can make the remote tank pump inoperative - pump itself,trim indicator,float switch,wiring - or a clogged filter

odds are,crank is good - you're gonna need a powerhead overhaul/replacement

getting the powerhead off can be a little difficult - but,having pulled probably 20/25 v6 powerheads over the years -shift rod replacement,you develop a few tricks...

htillman · #6 12-06-2014, 12:22 PM

My ETEC had issues running above 4000 rpm. Finally took it to my mechanic that found when the motor was installed on the boat the fuel line, oil line and shift throttle cables were somehow twisted and kinked causes many issues. The one that I never saw was the issues with the oil line. This motor is an 2009 with only 90 hours when I purchased the boat and motor in the summer. Up until now I was worried I purchased a motor with major issues. The mechanic told me I was fortunate I did not ruin the engine by starving it of oil. I never got an oil alarm, only fuel alarms

Bushwacker · #7 12-06-2014, 08:40 PM

Quote:

Originally Posted by htillman

. . . The mechanic told me I was fortunate I did not ruin the engine by starving it of oil. I never got an oil alarm, only fuel alarms

E-TEC's have a sensor that detects pressure pulses from the oil pump. If it doesn't sense any pulses, they'll set a "No Oil" alarm and go into safe mode, so it's pretty hard to kill one due to oil problems. Plus if you run full synthetic XD-100 oil, you can get by with about 1/3 less oil flow.

Fuel starvation is a whole other issue however and has killed many motors of all brands! I suspect that overpowered boats are the most susceptible to this problem. A slight restriction that causes motor to run lean but almost reach full power is probably worse than a severe restriction like you had that's more obvious!

htillman · #8 12-06-2014, 09:46 PM

Another lesson learned is to use 100 oil. Another issue was the gage. It only gave a high fuel level alarm no matter what was happening. The mechanic replaced the gage with the new style electronic gage and made sure everything worked. Finally got a printout on the engine. Working properly alarms are a good thing