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Jason, Marine Mechanic
Category: Boat
Satisfied Customers: 16206
Experience:  Degree in Marine Technology. Gas and diesel marine mechanic.
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I have a 2001 ox 66 yamaha 250hp if i give it to much

Customer Question

i have a 2001 ox 66 yamaha 250hp if i give it to much throttle it cuts out like i shut it off. i also noticed that the rpms are running a little higher with less top end speed
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else important you think the Marine Mechanic should know?
Customer: no. thanks
Submitted: 1 year ago.
Category: Boat
Expert:  Jason replied 1 year ago.

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

1. Yamaha has been calling many different engines OX66 for close to 25 years, what is the actual model number on your engine?

2. How long have you owned this engine for, and has it ever been any different or better for you in the past?

3. How old is the fuel?

4. Have you done anything on your own yet to troubleshoot the issue, if yes, what have you done?

5. What kinds of questions did you have for me?

Customer: replied 1 year ago.
I've owned the boat for about 6 months. Only thing I've done is replace the spark plugs and the prop.
The sticker with the model number was painted over so not sure if model number, is there another way to get or look up model number?
I top off fuel every weekend and I use ring free in the gas.
Expert:  Jason replied 1 year ago.

Hmmm, if you pull the engine cover off are they any stickers on the engine block or flywheel cover stating the model number?

Customer: replied 1 year ago.
I'll check when I get home this afternoon. I forgot to mention. Up until about a month ago the boat ran great. Then I didn't go out for about a month and that's when I noticed it running a little different. I thought bad gas. I replaced the fuel water separator. Then this weekend I notice I'm running higher rpms. The boat takes off fine gets on plane fine. I used to be about 38 mph at 5000 rpms. Now I'm about 28 at 5000rpms.
Expert:  Jason replied 1 year ago.

Without the model number I simply don't know which engine you have. Let me know what you hae for a model oce you find it and we can take it from there.

Customer: replied 1 year ago.
Expert:  Jason replied 1 year ago.

Got it. If it stalls out the faster you go it sounds like it's starving for fuel. The first step would be to change the fuel filters on the engine. If it still does it, the 2nd step would be getting a portable fuel tank and running it on that in order to rule out any tank or plumbing related issues. Is that something you can do?

Customer: replied 1 year ago.
I can do the external gas. Gonna be a few days tho. Hurricane Matthew coming.
Expert:  Jason replied 1 year ago.

I'm in florida, I know :( Let me know how you make out.

Expert:  Jason replied 1 year ago.

Hello. Just checking in. Hw did you make out?

Customer: replied 1 year ago.
Not back in Florida yet. It will be this coming weekend before I get a chance to try that.
Expert:  Jason replied 1 year ago.

Okay, let me know how you make out.