2001 80hp Yamaha 4-stroke

[CNY Lee]

It seems to start rough and had to keep running the first couple of minutes and it feels like a plug isn't firing until it get's warm and then she runs like a champ. I called the Yamaha dealer and they said it was common for this year hp 4stroke and I need to get the carbs adjusted. Does this sound right?

Thanks

Lee

[marine_man]

I would say that any larger, 4 stroke carb motor will require carb adjustment from time to time, especially when it comes to synch & linking the carbs so they all work in unison well. I don't think it's too far off.

marine_man

[PerchJerker]

I am by no means a boat mechanic but I have heard of that carb issue on 4-stroke Yamahas.

[marine_man]

 Originally Posted By: marine_man

I would say that any larger, 4 stroke carb motor will require carb adjustment from time to time, especially when it comes to synch & linking the carbs so they all work in unison well. marine_man

Let me re-phrase that.. at one time or another, a larger 4 stroke carb motor will require a carb adjustment. I would not classify it as a regular thing, as in needing to be done once a year, but as something that could need to be adjusted.

marine_man

[EXTREME]

I have a 80hp yami and it did the same thing last year kindof. It all of a sudden was running in 2 cylinders. I brought it to the dealer and what they did amazed me. They took the fuel line off the fuel pump...took the carb drain off...then blew air into the fuel line. Worked like a charm. I figured it was bad gas from the start, because I had to do it later in the year 2 or 3 more times...at least until that gas was out of it. Since then it has been a great running motor. I have heard that the jets are really small in the carbs...easy to have blockage problems.

[CNY Lee]

Thanks Extreme, would you have any diagrams of what I should be looking for to do what you did?

Thanks

Lee

[EXTREME]

I don't have any diagrams, but should be able to explain it. On the bottom of all your carbs there is a brass nut. Just unscrew it...gas will come out of the carbs, so be ready to sop it up. When all of them are opened, disconnect your fuel line that splits to the different carbs. Gas will run out of them as well. Take your compressor line and do short bursts of air into the lines. I did the equiv. of about 3-4 seconds worth of bursts. Put back together and try in the yard with the suction cups on the motor. I don't know if this is the most "appropriate" way to do it...but the dealer says he does it all the time. It worked on mine