Yamaha idles high

[tomfishhunter]

yr2000 F115TRXY My motor has idled high(1000-1100rpm) off&on for 2yrs. Warm or cold. When I'd take it to the dealer it would run fine. Can't fix it if it ain't broke. Now it idles hi all the time. The dealer is set up for snowmachines now and can't work on it.I want to fish for winter kings and need help. Anybody familiar with this problem? It's not in the cables. Thanx

 

[WillyBWright]

Re: Yamaha idles high

Is it idling high in or out of the water? It wouldn't be unusual for any motor on muffs to idle high out of the water. Otherwise it's computer controlled and there isn't much anybody can do about it except make sure the throttle is returning all the way to idle. You should also know that it HAS to be at idle to start and run properly. Otherwise the computer sees a value it doesn't like and defaults to a program that will allow the motor to run, but not in full tune. Warm-up levers are probably the #1 cause for certain running issues that are simply operator error. Loose battery connections come in a close 2nd. You also need AT LEAST a Heavy Duty battery. If I had a dollar for every EFI that came in with problems that related directly to a Regular Duty battery... <br /><br />I'll give you an example. We had a customer come in with a SeaDoo with a Merc EFI Sport Jet. He had it to the selling dealer over and over again with odd problems and they never were able to straighten them out. I saw the problem in 10 seconds. They had put in a light-duty trolling motor battery. I put in an Extreme-Heavy-Duty battery and all their problems mysteriously went away. You'd be amazed how many dealers just put in the cheapest crap battery they can get.

 

[tomfishhunter]

Re: Yamaha idles high

Thanx for the reply. It does it in the water or on the muffs. I never had a problem with it with the muffs in the past. I usally flush it after fishing. I learned long ago about not using the fast idle lever on these computer controlled units. I also have two battery's and a switch. When I unplug the orange conn.(thermo cpl.?)on top of the engine it idles@ 900rpm. Still to high. Thanx

 

[tomfishhunter]

Re: Yamaha idles high

Would a bad thermostat cause the computer to act that way?

 

[rodbolt]

Re: Yamaha idles high

hello<br /> yes it can. you need to check the timining at idle. also test/check that the throttle shutters close. if the timing is anything other than 4*ATDC check the t-stat,thermosensor and tps voltage. all the checks can be made with key on engine off except timing.EFI is so simple it baffles most techs. however it can do strange things. but the engine is an air pump. more fuel more air faster speeds. if the throttles dont close it will allow more air causing faster speeds. if the TPS is wrong the computer may think the throttle is open and air through the ISC control and the fuel pulsewidth.<br /> a quick setup on the laptop can confirm which sensors are working and which are not.