2007 Yamaha 15. Throttle won’t open up at top end.

Anyone know how the spark is advanced on this model. (Mechanical or electronic).
The carb is ok, jets clear, but won’t rev up.

2 stroke or 4 stroke ----Model # is ?------Have you confirmed spark on both cylinders ?------Did problem develop suddenly ?----How did it run for you last week ?

racerone said:

2 stroke or 4 stroke ----Model # is ?------Have you confirmed spark on both cylinders ?------Did problem develop suddenly ?----How did it run for you last week ?

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The engine Is a 2007 4 stroke. Stored for a year. Both cylinders firing. Model “F15”

I am not there to help you / prod you with your work.-----I would say a blockage in the carburetor or a compression issue.---Are the valves moving ?-----How did it run for you before you stored it for a year ?

racerone said:

I am not there to help you / prod you with your work.-----I would say a blockage in the carburetor or a compression issue.---Are the valves moving ?-----How did it run for you before you stored it for a year ?

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It has always run fine. Prime start and jets are operational. Starts and idles fine. Runs smooth up to 3/4 throttle. No top end.
i am wondering how the spark is advanced. (mechanically like on the old ones or electronically)?

Why the reluctance to provide the model identity? Is the motor "hot"?

What country are you in? Here in the USA there were five different F15XXXX models offered. F15CELH, F15CESH, F15CMLH, F15CMSH and F15CPLH.

Is your motor one of these five? If so, which one?

The more information that you can provide the better the answer(s) you will receive. Otherwise everyone is left having to guess.

2

boscoe said:

Why the reluctance to provide the model identity? Is the motor "hot"?

What country are you in? Here in the USA there were five different F15XXXX models offered. F15CELH, F15CESH, F15CMLH, F15CMSH and F15CPLH.

Is your motor one of these five? If so, which one?

The more information that you can provide the better the answer(s) you will receive. Otherwise everyone is left having to guess.

Click to expand...

Reluctance? I am a disabled 75 year old and getting around to get numbers is difficult. I am on the west coast of van island B.C. Canada. The model is 15ML HG.
Your suggestion that the motor is “ hot” is rude, and I think the administrator should weigh in.

Where is the administrator when needed? Covid has you getting "testy" does it?

I am trying to help you. But you need to help me. Help me help you.

All Yamaha four strokes begin with the letter F. F as is Four stroke. You say that it is a four stroke. But you now say that the model is 15ML HG. The owner's manual has a section where you wrote down the specific model and serial number. Too difficult to open up the owner's manual is it?

You being in the land of the frozen north, I would suspect that you bought the motor from a Yamaha Canada dealer. Here is what Yamaha Canada says are the F15 models they offered in the year 2007. If you have one of these models then the timing is electronic.