Yamaha F90 Surging at Idle

reptyls

Recruit
Joined
Jun 13, 2010
Messages
4
2005 Yamaha F90TLRD EFI motor surges from about 400rpm up to 1500rpm and then will eventually die. It will usually start right back up and start surging again. Runs fine Midrange and top end. Sometimes it will run fine for the first 30 to 60 seconds then starts surging. I have replaced VST filter and cleaned VST, Cleaned injectors, replaced ISC Valve, tested TPS and Intake Pressure sensor. YDS does not show anything out of spec. Any other thoughts. I am pulling my hair out on this one.
 

mommicked

Lieutenant Commander
Joined
Dec 15, 2009
Messages
1,700
Re: Yamaha F90 Surging at Idle

Im no expert,but I had starting/idleing issues w my 03 F90,carbed engine.It ran fine after a few mins idle and at higher RPMs. the rough idle and cutting off stopped when I replaced my primer bulb w a new solvent or Ethenol safe one.It now starts and idles well.
 

reptyls

Recruit
Joined
Jun 13, 2010
Messages
4
Re: Yamaha F90 Surging at Idle

Thanks, I replaced the bulb and fuel lines when I cleaned the VST. Still looking for any Ideas.
 
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