2006 yamaha 150 vmax 2 stroke

[mearguy71]

I have been troubleshooting a problem and looking for any suggestions. When I start the motor in the driveway with the flush kit hooked up it sounds fine and even when I occasionally rev it up it sounds good. When I take it to the lake to test it, as soon as I put it in gear it starts making a noise (if you were to say tack tack tack out loud over and over thats what it sounds like) then dies. First step I drained the fuel tank and replaced the fuel water seperator and then took it to the lake to test. no go! Today I replaced all the spark plugs with the ones recommended by yamaha. The ones in the motor were the same type but they were all wet fouled. Took it to the lake and tested it and same result. Is this possibly a lower unit problem since it happens when in gear? Any suggestions?

 

[flyin4delta]

Re: 2006 yamaha 150 vmax 2 stroke

Have you checked your compression in all your cylinders?

 

[Bamaman1]

Re: 2006 yamaha 150 vmax 2 stroke

When you start'em in the driveway using a water cuff, a 150 hp motor is so loud that you cannot hear anything but the exhaust.

+1 on #2 about checking your compression. Sounds as if you may also have a lower unit problem with the tack, tack, tack noise. Two strokes are actually pretty simple mechanically--only moving engine pieces are pistons and crankshaft.

As long as my Yamie 115 is running okay, I just change plugs every year and change lower end grease every 2 years. Every 4 years or so, the carbs have to be cleaned. I'm on my 26th season with it. It's difficult to kill a big Yamie 2 stroke engine.

 

[mearguy71]

Re: 2006 yamaha 150 vmax 2 stroke

I will get a test kit for the compression check. A couple guys on another boat made the comment that i needed to get the upper unit checked out when they heard the noise. I dont know what their experience level is though. Would the lower unit cause the engine to stall even at low speed or is likely carbourator problems?

 

[CHIEF TERRY]

Re: 2006 yamaha 150 vmax 2 stroke

To your question ,would the lower case trouble cause the engine to stall i would say yes because when it is in gear the are working as one unit , if there is gear damage it could stop it from turning and also stop the engine , inspect the lower unit, once removed you can put it gear and turn it by hand ,if there is damage it will show up !DID YOU PUT IT IN GEAR WHILE IN YOUR DRIVEWAY ??