90 four stroke problem

[11andy11]

I have a 2004 yamaha 90 hp four stroke with 35 hours. Last time I took it out it would stall at idle. After numerous attempts to start it, i finally got it to idle. When I throttled up it would stall at about 1100 rpm. When i throttle up and get past that stall point it would max out at about 3500 rpm. Any ideason what my problem might be?

 

[rodbolt]

Re: 90 four stroke problem

check compression and spark. test the TPS and inspect the fuel system. most of the problems come from dirty carbs.

 

[rodbolt]

Re: 90 four stroke problem

oh, the 04 did not have the TPS, that makes it even simpler.<br /> the 4 stroke carb passages are very small and prone to clog.

 

[11andy11]

Re: 90 four stroke problem

I thought the 2004 was fuel injected. I guess you mean an injector it clogged.

 

[rodbolt]

Re: 90 four stroke problem

nope 04 was carbed,05 was the first model run of the EFI F90.<br /> thats why a model number is always so nice, it identifies the motor

 

[11andy11]

Re: 90 four stroke problem

Thanks for the clarification. It looked like carbs to me but I don't know alot about outboards. I have a manual on the way. I am fairly mechanically minded, do you think this is something I should attemp myself or take it to a tech? Thanks again for the help.

 

[rodbolt]

Re: 90 four stroke problem

well if ya cant tell the difference between EFI and carbs I would suggest a tech. however if you get the factory service manual and the tools essential for carb repair its not difficult just time consuming.

 

[bigbrownbuku]

Re: 90 four stroke problem

tools will include a balancer which dont come cheap.

 

[11andy11]

Re: 90 four stroke problem

good point rodbolt.

 

[rodbolt]

Re: 90 four stroke problem

11any11<br /> I did not mean to sound sharp but you asked,<br /> the carbs on that four stroke require a manometer to balance,can it be done without it? yep. can it be time consuming and frustrating? yes. the carbs themselves are straight fwd, its the sync of them that can irritate. but withut that model number I cant tell ya a lot about it.