Yamaha F150 only starts in neutral with throttle or by squeezing fuel bulb

AKboater1

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Joined
Aug 25, 2024
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1
I've been boating in Alaska again for a couple of years, and I've learned a lot from reading the posts in this forum. I can't find an answer to what happened to me yesterday, so here's my question: I run two 2011 Yamaha F150s. I took my boat out, and anchored overnight. In the morning, both started normally. After my first stop, the port motor wouldn't start in the start/neutral position - it would turn over but not start. However, it would start if I put it into neutral and gave it gas (I know that can be dangerous, but had no other option). But even after it ran it in neutral for a bit to get the motor warmed up, if I reduced throttle back to the start position in order to engage the prop, the motor would die and not start. Next, I just started squeezing the fuel bulb as I tried to start the motor. Between that, and running it in neutral with some throttle, it finally started and I was able to get it in gear. It ran fine for over an hour, and then I stopped to pick up shrimp pots. When I tried to start again, same deal - the motor wouldn't start in normal start without pumping the bulb as I turned it over. Then it ran fine the rest of the way back to harbor.

Any thoughts or suggestions?
 

99yam40

Fleet Admiral
Joined
Sep 7, 2008
Messages
9,116
do those motors have fuel coolers ?
sounds like you VST is boiling off the fuel in there causing a too rich condition in the intake, so you have to add more air for it to burn.
and pumping the bulb fills the VST so that pump can pressure up the rail
 
Last edited:

crazy charlie

Vice Admiral
Joined
May 22, 2003
Messages
5,581
Had similar and replaced fuel pumps and problem solved.Pumps are inexpensive and easy to change.Charlie
 
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