# Yamaha F60 Idle Issue



## TidalFly (Sep 1, 2015)

Microskiff,

I’m hoping for some help in diagnosing a motor issue. I’ve got a 2015 Yamaha F60 that is sputtering and shutting off at idle. When this starts to occur, the bulb can be pumped to keep the motor running. Motor has no issue when running at higher RPM’s. Fuel water separator and fuel filter in canister on motor are both brand new. Fuel line is 1 piece from tank to engine except for at the separator. In-line filter between the fuel pump and the canister on engine is clear. I just replaced the fuel lift pump on the back of the block thinking it may be the problem and the problem persists. Seems like there may be some sort of fuel flow restriction that is preventing enough fuel from getting through at idle, but not creating issue at higher RPM’s?? Hoping for some thoughts so I can continue to troubleshoot.

Thanks.


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## WilliamYoung (11 mo ago)

Spark plugs?


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## Smackdaddy53 (Dec 31, 2012)

Run the motor on a remote fuel tank


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## iMacattack (Dec 11, 2006)

Start with what Smack recommends. Strictly for reference, if you have a similar issue to what I encountered this post may help you out.









90 Yamaha F90 TRL stalling immediately after starting...


So just looking for some ideas. Christmas day fishing trip and it was cut a bit short. Did have fun and bought a bunch of snapper and a couple sharks. So ran fin till today. In the morning it started fine and ran wonderful. Than after a long run it would stall while throttling down. Symptoms got...




www.microskiff.com


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## TidalFly (Sep 1, 2015)

Thanks I will try suggestions and circle back


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## Smackdaddy53 (Dec 31, 2012)

TidalFly said:


> Thanks I will try suggestions and circle back


Ahh the psaki bomb approach!


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## TidalFly (Sep 1, 2015)

Going to run on remote tank first to rule out tank to engine issues. If problem persists, planning to place clear line just before fuel pump to see if air bubbles are in line before getting to pump. Will report back.


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## TidalFly (Sep 1, 2015)

Update: ran motor on hose at idle with brand new remote tank with brand new ethanol free gas in it for 30 minutes, sputter and die issue did NOT occur. 

As I type this, motor is 45 minutes into idle on hose connected to boat fuel line as it was when this issue presented itself. So far 45 minutes in the sputter and die issue has NOT occurred.

At this point I’m not really sure how to explain the situation. If this is useful knowledge, the issue occurred in Flamingo when I had towed down from South Carolina. The problem presented itself Monday and was constant (sputter/die after idling for a short period but ran fine when running at higher RPM), changed the fuel lift pump on Wednesday. Problem persisted Wednesday afternoon with no change after replacing fuel pump.

Only thing I can speculate is MAYBE condensation in fuel created by change in temperature from SC to South Florida?? Not even sure if that’s a realistic thing to speculate.

I guess at any rate, I’m not able to recreate the problem at the moment. Granted I haven’t actually run the boat at different speeds since I got back, just on the hose.

Any thoughts?


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## Smackdaddy53 (Dec 31, 2012)

That test eliminates the motor so look for a fuel tank vent not venting, screen on pickup tube in fuel tank restricted, fuel hose liner collapsed somewhere, primer bulb issue or fuel filter issue.


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## TidalFly (Sep 1, 2015)

Ok, going to put it in tomorrow and run at different RPM’s and see if it has issues when going back to idle. 

Random question, any idea how long a 60 hp four stroke takes to burn through gas in the engine? Just wondering having gone from remote tank back to boat tank, how long it was running remote tank gas still before burning any boat tank gas.


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## iMacattack (Dec 11, 2006)

The sputtering at idle, does it happen when in gear under load and/or in neutral?


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## TidalFly (Sep 1, 2015)

It did it both in gear and at neutral this week in the glades.


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## TidalFly (Sep 1, 2015)

Update: Just ran the motor on the hose with clear piece of tubing on intake side of fuel lift pump. Purged air via bulb before running on boat fuel line. Runs without bubbles for a period then bubbles begin to appear in clear tube. Connect remote fuel tank/line (brand new) and repeat the same process. Bubbles appear after the same
amount of run time. This would seem to indicate there is an issue within the engine, not the fuel line from tank to engine. Connections at canister fuel filter on engine are sealed tight with no smell of fuel, and the canister itself is intact (no cracks/etc). Anybody have an idea of somewhere else on the motor where air could be entering the fuel line? Maybe the fuel line connection at the motor?


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## Smackdaddy53 (Dec 31, 2012)

You won’t smell gas if the system is drawing air into the fuel system. Where your hose is the leak is before it.


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## TidalFly (Sep 1, 2015)

Yep, sniffed all connections between the fuel line connection on front of the motor and the clear section I put in while motor wasn’t running and smelled no fuel, but clearly there’s air entering somewhere. In theory, I could just replace everything between fuel line connection and the lift pump and it should eliminate the issue correct?


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## Smackdaddy53 (Dec 31, 2012)

TidalFly said:


> Yep, sniffed all connections between the fuel line connection on front of the motor and the clear section I put in while motor wasn’t running and smelled no fuel, but clearly there’s air entering somewhere. In theory, I could just replace everything between fuel line connection and the lift pump and it should eliminate the issue correct?


From the information you provided, yes.


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## mcmsly2 (Apr 8, 2010)

TidalFly said:


> Microskiff,
> 
> I’m hoping for some help in diagnosing a motor issue. I’ve got a 2015 Yamaha F60 that is sputtering and shutting off at idle. When this starts to occur, the bulb can be pumped to keep the motor running. Motor has no issue when running at higher RPM’s. Fuel water separator and fuel filter in canister on motor are both brand new. Fuel line is 1 piece from tank to engine except for at the separator. In-line filter between the fuel pump and the canister on engine is clear. I just replaced the fuel lift pump on the back of the block thinking it may be the problem and the problem persists. Seems like there may be some sort of fuel flow restriction that is preventing enough fuel from getting through at idle, but not creating issue at higher RPM’s?? Hoping for some thoughts so I can continue to troubleshoot.
> 
> Thanks.


I’ve just been through this exact same thing. Took me a year to figure it out. My vst was not venting properly at idle. Everything you’ve said yours is doing mine did. Next time it cuts off while idling, pop the hood off and pull the hose off the solenoid valve assembly. I’d bet a ton of pressure releases. If you want to give me a call I can explain exactly what I think is happening and how to fix it.


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