1993 Yamaha 150 2 stroke

[waterboy2327]

If I run faster than 4000 rmps, I get an alarm. It is not overheat or oil. If I let it sit for a minute the alarm will shut off and run fine unless I go above 4000. The only thing I can find is the bubble on the fuel line will not be full when I get the alarm. If I pump it up that by itself will not stop the alarm. I had the motor serviced earlier this year and they could not find the problem. Is there a fuel restriction alarm?? I have a Racor seperator which was replaced last month. I am planning to change the fuel lines from the Racor to the motor including the bubble. Any ideas, Help.

 

[Ray Neudecker]

Re: 1993 Yamaha 150 2 stroke

The alarm is for either heat or oil. If there are no indications on the guage for oil, then it is overheating.

 

[waterboy2327]

Re: 1993 Yamaha 150 2 stroke

Just spoke to a mechanic at a Yamaha shop, advised it could be a Lean Alarm. I am changing the fuel lines and bubble today. Is there a Lean Alarm??? It's not oil and according to my temperture gauge I am running cool. I also checked the block while running and it doesn't feel hot. I also checked what was changed on the last service, and the fuel pumps where changed. I really believe I am not getting enough fuel to the carbs at high RPMs. Any more ideas??

 

[Ray Neudecker]

Re: 1993 Yamaha 150 2 stroke

There is no lean alarm on that engine.

 

[waterboy2327]

Re: 1993 Yamaha 150 2 stroke

OK, well I have changed the fuel lines from the engine to the water seperator and replaced the bubble. I also noticed that the vent for the fuel tank broke off and the hose fell inside the hull. I will replace this as well. Could this have had an effect??
I appreciate the replies, I am not a mechanic by any means, but am trying to learn some, again thanks.

 

[Ray Neudecker]

Re: 1993 Yamaha 150 2 stroke

Excellent steps to take to protect your engine. May not have any effect on the other problem. Do a compression test to be sure a head gasket isn't leaking. Get a factory service manual for that model. The info will allow you to do a lot of trouble shooting and testing. Those hours come high at most shops.
Many times a fuel restriction will cause a surge as you run up against it

 

[waterboy2327]

Re: 1993 Yamaha 150 2 stroke

Again thanks for the replies, I plan to get the mechanic who has serviced it in the past to do a compression check, and will attempt to get the manual for my motor.