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Charles, Marine Mechanic
Category: Boat
Satisfied Customers: 3729
Experience:  US Navy (Ret) Certified Mercury Marine Tech with over a decade of repair experience.
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I have a yamaha 200hp engine and when i put a full tank of

Customer Question

I have a yamaha 200hp engine and when i put a full tank of gas in it causes motor to go into a safe/protective mode and wont allow me to go above 2000rpm, 5mph, etc...
Sometimes the alarm goes off. I had the thermostat replaced a month ago and that didn't change it. I put the yamalube in it too to help it run smoother.
It was driving perfect as i drove to marina at half tank. within 500 ft after i left the marina it went into this shut down phase.
Submitted: 11 months ago.
Category: Boat
Expert:  Jason replied 11 months ago.

Hi Matt, my name is Jason.

Have you had the engine hooked up to Yamaha's diagnostic laptop in order to pull codes yet?

Customer: replied 11 months ago.
No, i have the boat on a boatlift and do not have a trailer so i have had a mechanic come to the lift and he thought it was the thermostat that was giving the signal first, ( as there was no water coming out of the back of the boat when running, but that was a separate issue)
Is there any way i can do that myself ( i have a code reader for my car)
Expert:  Jason replied 11 months ago.

Unfortunately no, the code reader is proprietary to Yamaha, and automotive code readers will not work. Yamahas system is called YDS, Yamaha Diagnostic System. Its' a laptop based system. It's not to terribly expensive if you wanted to buy it, but that is the only way to pull codes out of the engine. Click this link, this is the system -

Expert:  Jason replied 11 months ago.

Was there anything else Matt?

Expert:  Jason replied 11 months ago.

I do want to make sure you are happy with my service before you go. If you had a further question on the issue by all means feel free to ask. If not, Just in case you do not understand the way the website works (and some folks do not). You do have to put forth a positive rating in order for it to credit me for helping you. When ratings are not done, the website simply keeps your deposit and they will not credit me. The ratings box is located at the top of the screen. To rate, you must select the star you wish and also confirm it. Please let me know if you run into any problems or errors when trying to do it. If you do have a problem, or if you can not see the ratings box which is at the top of the screen. Please reply back "I rate Jason's service _______" and fill in the blank.

Questions do not close out, so if you have to come back later on with follow up questions to the issue you still can even after doing a rating.

Thank you

Customer: replied 11 months ago.
No i have had a very busy day and just getting to this now.
no i am not satisfied with the response. i was hoping to hear your educated insight on the problem, if you've had previous experience, is it common for the yamaha engine or grady white boat. I can call a local mechanic for free and he will say bring it on and we will hook it up to the computer, but i dont have a trailer and was hoping for you to say it may be this or this, and here's why. Than i can hire someone to fix that exact part
Expert:  Jason replied 11 months ago.

If I (or anybody else) could fix alarm problem without hooking up the diagnostic laptop to the engine then there would be no need to have a diagnostic laptop. I think maybe your expectations were a little to high here.

Customer: replied 11 months ago.
Well do you have any idea why when i fill it up the boat goes into that 'limp home mode" that i experience. Omit the alarm sound for now, that is rare. But everytime i fill up full tank, and occasionally after anytime i put any amount of gas in it it goes into this protective state? As if it's trying to protect it from overheating, or protect from engine damage so it maximizes rpm at a low level.
Any ideas? Have you ever experienced that or heard of that before?
Expert:  Charles replied 11 months ago.

Hello, my name is***** will assist you.

You gave all the clues. when you add fuel from a marina, allot of times, what you are getting is water mixed in with it. This would cause the alarm on the water sep filter on the engine. Look closely at it and you will see that there actually 2 layers inside it. the bottom being water. and since you have water there, there is water in the fuel tank of the boat. you will need to call a local company that can "clean" fuel in a boat tank, Basically they recirc the fuel through several filters to remove all water and debris from it.

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