2015 F115 abrubt shut off

[b.e. coyote]

Hi all,
Last outing, my 2015 F115 with less than 80 hours began abrubtly shutting off at 3000 plus rpm. It was exactly like the kill switch lanyard was pulled.

Didn't sputter or choke. Just would die. It would start right back up. Did this 4-5 times as quickly as rpm climbed above 3000 rpm. Not sure if there was a specific rpm that it died. It was choppy so it was also getting bounced some.

I was a about 6 -8 miles from the dock. Kept it at 2500 rpm and got back without a problem.

Today I had it idling in a barrel and couldn't get it to die by moving the harness around or wiggling any connections.

Any help? Definitely assume electrical.

[b.e. coyote]

I did find there was a service bulletin on this year f115 about a throttle body bracket that would crack, and lose ground causing this issue but I called yamaha and my serial number falls outside the effected run.

[TownsendsFJR1300]

I did find there was a service bulletin on this year f115 about a throttle body bracket that would crack, and lose ground causing this issue but I called yamaha and my serial number falls outside the effected run.

With that known issue, ^^, I'd first be checking that TB bracket myself...

.

[b.e. coyote]

Going to look at it today but my outboard should have the new bracket according to the serial number and a call MamaYama.... Had a couple FJRs myself. Great bikes!

[99yam40]

only thing I can think of that might be related to RPM is the VST running out of fuel at higher RPM.
If the rail pressure drops to nothing due to sucking air instead of liquid fuel the motor would die.
all cylinders would stop getting fuel

with the key still on the VST would fill back up or at least get enough fuel back in it to fire back up.

did you try to pump the primer bulb to see if that would help?


maybe turn the key off as soon as the motor dies, and then see if it takes some pumping of the prime bulb to fill VST back up to firm bulb.

[b.e. coyote]

[QUOTE=99yam40;n224833]only thing I can think of that might be related to RPM is the VST running out of fuel at higher RPM.
If the rail pressure drops to nothing due to sucking air instead of liquid fuel the motor would die.
all cylinders would stop getting fuel

with the key still on the VST would fill back up or at least get enough fuel back in it to fire back up.

did you try to pump the primer bulb to see if that would help?


.

You might be on to something. I emptied the water seperator into a clear jar to check the gas. Gas looks fine, no water.

I pumped the bulb quit a bit to fill the seperator. Didn't get hard. Disconnected the fuel line from the outboard, its not pumping gas through, removed the seperator again and it is basically empty.

The bulb should be pumping gas through the hose when not connected correct?

I do not see any physical damage to any part of the fuel line.

[99yam40]

bad seal on the filter maybe, or some where else sucking air

[b.e. coyote]

ok, is this odd?

I moved the bulb before the filter/seperator and it quickly filled the seperator by pushing gas into it and gas came out the hose of the output of the filter seperator housing as it should. I moved the hoses back and with the primer bulb between the filter and outboard it will not pull the gas through the filter even though the filter is now full/primed?

[b.e. coyote]

bad seal on the filter maybe, or some where else sucking air

and that would be enough to keep the vst tank from filling up at higher rpm?

[99yam40]

ok, is this odd?

I moved the bulb before the filter/seperator and it quickly filled the seperator by pushing gas into it and gas came out the hose of the output of the filter seperator housing as it should. I moved the hoses back and with the primer bulb between the filter and outboard it will not pull the gas through the filter even though the filter is now full/primed?

to me it sounds like it is sucking air into the system at the filter

[99yam40]

and that would be enough to keep the vst tank from filling up at higher rpm?

if the lift pump is pulling air and fuel, it may not be able to keep up

[b.e. coyote]

I'll probably replace everything from the tank to the outboard tomorrow. Do I really need a primer bulb?

[99yam40]

I would look hard at the water separator/filter instead of replacing everything, but that is just me.
how do you expect to prime the system without a primer bulb?

[b.e. coyote]

Replaced the seperator, new hose and bulb. Left the WS filter mount.

Wasn't sure if the 4 strokes really needed the bulb and thought it and 2 extra connections because of it just might be an extra point of failure.

Going to take it out tomorrow morning. Hopefully that was the issue.

I'll report back, good or bad.

[99yam40]

are you sure the mount does not have corrosion pitting along the sealing surface?
which side of the WS did you put the primer bulb this time?
and did it prime the motor and get firm?