2003 2 stroke 150 throttle issues

[jkoller1975]

I have 150he 2 stroke yamaha on a 2020 cc keywest. I have owned the boat since new and constantly have it serviced. 3 years ago I started having issues with the boat not getting to full throttle or sputtering from 4200 down to 3800rpms. I have had two different marine repair facilities look at it. 1 is yamaha factory certified. The last marine just rebuilt all three carbs and it did not fix the propblem. I have dumped lots of money into this issue and I am getting completely frustrated as I do not know where to go for help. I am in NJ but will travel 60 miles to solve this problem. Please help.

[Sequoiha]

it sounds to me like the timer base is not traveling to full advance timing, they have been known to stick from time to time, It is the long arm attached to the throttle linkage, Move the throttle to WOT, and manually check the arm is all the way forward.

[99yam40]

I have 150he 2 stroke yamaha .

there are I believe 9 different 150 Yamaha motors listed for 2003 but none are a 150he.
You might get better responses if you give the complete correct model # of your motor.

Do a search and find a service provider that employes a Yamaha master tech that can troubleshoot your motor properly

[jkoller1975]

Thanks

Sorry, the model # is 150 TXRB

[boscoe99]

Check the timing mechanism as noted. If it is not advancing per specification then a repair is needed.

Check the choke plates on all three carburetors to make sure they are all fully open.

Check that the battery cables are clean and tight at both ends. Also at a battery switch if one is installed.

Another thing to do is to verify that it is or is not a fuel related issue. Get a small spritzer bottle and put some gasoline in it. Remove the intake silencer and have someone spray some additional fuel into the carburetor inlets when it appears to be down on power or RPM. Does it stay the same or does it pick up and run like the proverbial scalded dog when fuel is added?

[99yam40]

put a little oil in that bottle too so there is some lubrication going in with the gas.
Or is this a motor that injects oil separate from the gas?

[rodbolt17]

or find a real dealer that employs a real master tech, as noted by the school certs on the wall, and have them water test it with you when they are done.
we do.
if a customer wants a water test? no problem.
however its still at 90/hr.
but you wont believe how much we can teach a customer about his boat that the selling dealer did not and the ship shape stupid TV thing cant.