2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

[itiswhatitis1]

The engine wont idle when I start it cold but once i rev the engine for over 10 minutes it will eventually idle on its own when it warms up. Any suggestions on how to correct?

 

[99yam40]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

Does this motor have the prime start enrichment system?
Model # would help some one look that up.

If so your system needs attention along with the carbs.
possibly cleaning all passages and check diaphragm.
Readjust like manual calls for after reinstalling.

Never hurts to check compression,spark, and timing to make sure motor is healthy
Might check on fuel pump to make sure it does not have a pin hole

 

[Natty Light]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

mine does the same thing when its cold. Instead of revving the engine I just bump the choke whenever it sounds like it's about to die. that keeps it running until it warms up. Every start up after that and each day following I don't have to do anything. It idles fine. It's just that first start after sitting for a week or two. Try tapping the choke instead of revving it.

 

[Capt Ken]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

That model should have prime start so if he advances the throttle too soon it will disable the fuel enrichment.

 

[itiswhatitis1]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

Does this motor have the prime start enrichment system?
Model # would help some one look that up.

If so your system needs attention along with the carbs.
possibly cleaning all passages and check diaphragm.
Readjust like manual calls for after reinstalling.

Never hurts to check compression,spark, and timing to make sure motor is healthy
Might check on fuel pump to make sure it does not have a pin hole

The model # I found is C90TLRZ and it does not have the oil injection I mix the oil on my own, does that tell you if I have the enrichment system or not? With that in mind what should I try first? Bumping the choke does not work. Its kind of annoying at the boat ramp lol.The only thing I have tried is changing my water/fuel separator and new spark plugs but I didn't check the spark or compression on it. Is there a website where I can get a manual for free?

 

[itiswhatitis1]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

Does this motor have the prime start enrichment system?
Model # would help some one look that up.

If so your system needs attention along with the carbs.
possibly cleaning all passages and check diaphragm.
Readjust like manual calls for after reinstalling.

Never hurts to check compression,spark, and timing to make sure motor is healthy
Might check on fuel pump to make sure it does not have a pin hole

Another issue I have is: only when I engage the throttle over 80% the over heat alarm sounds an the engine then it automatically slows it self down and when the alarm turns off I can get back up an run again. This has been a problem ever since I purchased the boat 3years ago. I can pull people on wake board or tube just fine an never over heat as long as I dont throttle to 80%. It pisses great steady stream I had a yamaha mechanic change the impellor an check the water pump and complete cooling system and he said everything checked out great and he don't even know what causes that. Any suggestions ???? I have know idea.

 

[Bosunsmate]

Re: 2001 yamaha 2 stroke 90 hp very hard to keep idling when cold

Maybe your overheat sensor is triggering off to early