yamaha 2000 150 2 stroke problem

[james1115]

Hey guys I have a problem with my motor and I can't figure it out. I start it up and it runs great. I start going and it is fine for about 20 minutes then all of a sudden the motor bogs down and starts to rev up then bog down then rev up and bog down and continue doing this while I can't go over 7mph when this happens. I throw it into neutral, rev it up really high, then shut it off and tilt my motor up then back down and it is back to normal for a little while until it happens again. I am getting really annoyed at turning the boat off, revving the engine and tilting my motor up and down 15 times a day. Does anyone know what this could be?

 

[esteym]

Re: yamaha 2000 150 2 stroke problem

I have the same problem with my motor. I know the problem is fuel related and it sounds like yours is the same. I cleaned out the carbs and checked the fuel lines for leaks, and drained the water/fuel seperator. nothing worked for me. Now I'm down to an obstructed intake in the tank and maybe installing an in line fuel pump.

I would say yours is located in the carbs. You most likely have some sort of debris in the bowl of your carbs, that is why tilting your engine up and down works. You may also want to check the water/fuel seperator, the secondary fuel filter,and air in your fuel line / leaks.

hope this helps

 

[james1115]

Re: yamaha 2000 150 2 stroke problem

well I agree that it is prob in the carbs. I bought the boat and it had some bad gas in it, the carbs were gummed up and not opening all the way so I started the motor and sprayed 1 full can of carb cleaner in each carb while the engine was running. The motor ran great now I have this problem. What do you think I should do? I got a new water seperator filter and drained it, and the new gas looks clean and free of water. I replaced the inline fuel filter and nothing has helped accept what I mentioned above. I thought it was electrical so when I turned it off andf back on it reset something. It almost feels like the high speed stator is kicking on and off.

 

[esteym]

Re: yamaha 2000 150 2 stroke problem

Pray it is not your strator. I dont think there is anything you can do other than buy a new one.

Work on everything else first. You said you had bad gas in the fuel tank, this could be part of the problem. The gas can gum up over time and cause a restriction. One guy posted here that he had a softball sized ball in his tank and it would roll in front of the intake and then away again causing similar problems. If you have access to the tank, open the access port and look inside for any debris also check the intake screen for particulate debris.

Spraying carb cleaner into the carbs will not clean out the bowls of the carbs. Your restriction could be there as well. You must rebuild these anyway after having bad gas in them. This is easy - with the manual - and the kits are cheap. I just did mine in two hours and the engine is running a lot better even though I did not see much gunk in them.

Did you check your fuel line for leaks? is your fuel line hose old/worn? if so you can have air get into your fuel causing this problem.

Lastly check the timing of your engine - it is a pain, but well worth it.

Oh and revving your engine in neutral can cause your engine to overrev or runaway and boom - no more engine.

 

[Ray Neudecker]

Re: yamaha 2000 150 2 stroke problem

The tilting of the engine may be freeing up a sticking needle. estym is right that the chances of it being a fuel restriction problem are the most likely.

 

[james1115]

Re: yamaha 2000 150 2 stroke problem

ok thanks guys I will try the carb cleaning then replace the fuel lines.