90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

[Bubinkaty]

I just bought this motor(1999 90hp) and the first time I brouht it out on water it will only run 2000rpm. I stoped and took motor out of gear and reved it up over 5000rpm put it back into gear and ran great for a hour. Turn off motor for 5 minuites start again does exact same thing, rev up again works perfect. So unless I rev my motor up in neutal motor will not run over 2000rpm. I have changed gas and plugs. Will run great in the driveway.

 

[lonewolf5347]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

Bub In Katy I would first go with the fuel system onboard fuel filter,change primerbulb and fuel lines,check carb's

 

[Bubinkaty]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

Thanks lonewolf I was looking at a new fuel filter anyway. I did have bad gas the other day and the fuel filter on the motor had a few specs of black particles in it. I hate to tear into the carbs when it never missed or thumped the other day but I will see what happen,s with new lines and filter.

 

[lcjim]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

Hi Bob in Katy, This is Jim in League City. I have the same problem with my 90 hp yamaha, maxed out at 2000 rpm. What did you find? email me at jimlegg56@hotmail.com<br /><br />Thanks, Jim

 

[spete]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

If you have an oil injected model it could be that the rev limiter is kicking in due to low oil? Buzzer should have sounded though. What may have happened is that when you stopped and the boat leveled out and there was enough oil in the main tank to pump again so it worked fine as long as motor's under-cowl reservoir had oil? Just a thought.

 

[Bubinkaty]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

I bought a repair manual and checked over my voltage reg, coils and rectifier could not find anything wrong so I went threw all my connections did find one semi-loose cable to my rectifier but still do not know if that was the problem. The first problem I had was bad gas so I replaced all the filters and installed a new online filter and dumped all the old gas. Have brought boat out three times and last did not have problem untill boating over 3 hours stoping and starting, when it happen I noticed that is was idlely high, turned motor off and never happen again. My motor does not have a oil injection on it and it is not getting hot to cause the motor to automatically run at 2000 rpm so in conclusion I think that I have a electronic signal issue or some wierd problem in the carberator,s. I will let you know if I ever isolate the problem. Good Luck

 

[lcjim]

Re: 90 HP Yamaha only runs 2000rpm until I rev it up in neutral!

Found my problem. No. 3 carb foat needle valve was gummed up. Motor would not run alone,on No. 3 cyl. with No. 1 and 2 plug wires removed and grounded, but started and ran by spraying fuel lnto No. 3 carb throat. No. 1 and 2 would start and run alone without spraying. <br /><br />Hope this helps.<br /><br />Jim in League City