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Jason
Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 14388
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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Yamaha 200 hp hpdi outboard! Runs fine to full throttle.

Customer Question

Yamaha 200 hp hpdi outboard! Runs fine to full throttle. After 20 minutes or so won't go over 4000 rpm's. Shut it off and it's fine for another period of time! What's this sound like
Submitted: 7 months ago.
Category: Boat
Expert:  Jason replied 7 months ago.

Good morning, my name is ***** ***** am I speaking with?

It could be any number of things. Step 1 would be to duplicate the problem, and then check for spark output with a timing light. This will tell you if it's a spark issue, of you have spark on all cylinders, a fuel issue. Is that test something you are able to do?

Customer: replied 7 months ago.
Jim
Expert:  Jason replied 7 months ago.

Hi Jim.

Customer: replied 7 months ago.
Runs fine at full throttle for a while then engine needs to be shut off and then fine again
Expert:  Jason replied 7 months ago.

It could be any number of things. Step 1 would be to duplicate the problem, and then check for spark output with a timing light. This will tell you if it's a spark issue, of you have spark on all cylinders, a fuel issue. Is that test something you are able to do?

Customer: replied 7 months ago.
I changed the large filter before engine. Looked clean. Drained vst tank,looked good. Has new high pressure pump last summer and worked fine. I have ordered fuel filter for side of engine, get filter and inline filter between vst and high pressure pump. If it's not any better would assume electrical!
Customer: replied 7 months ago.
Vst filter sorry auto correct can be a pain��
Expert:  Jason replied 7 months ago.

I hate to repeat myself but I'm going to ask this for a 3rd time... Step 1 would be to duplicate the problem, and then check for spark output with a timing light. This will tell you if it's a spark issue, of you have spark on all cylinders, a fuel issue. Is that test something you are able to do?

Customer: replied 7 months ago.
but not today ! I do have a spare coil also! Guess have to set up each plug with timing light and see results when problem occurs!
Expert:  Jason replied 7 months ago.

Correct. That is the only way to do it other than removing the engine from the boat and sticking it into the test tank. Let me know if you are loosing spark on cylinders when the problem happens, and we can take it from there.

Customer: replied 7 months ago.
Ok
Expert:  Jason replied 7 months ago.

Sounds good, keep me posted

Expert:  Jason replied 7 months ago.

Hello, just checking in. Have you been able to run the test?

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