Yamaha F115 Starting Mystery

[ARCWINSTON]

Hello all,
My '03 F115 has never missed a beat and starts first time every time until now. The last two times out it has failed to start in the middle of the day while out on the water.
It always starts at the ramp and runs fine. Both times at the end of a drift it just wouldn't start.
It turns over strongly but shows no sign of starting. Then in both cases it started right up when I tried it again about half an hour later. It then started/ran faultlessly the rest of the day/night.
There is plenty of fresh gas and it did it on two different fills from two different gas stations. The tank breather isn't blocked and the Racor separator/filter element is recently new.
The squeeze bulb was hard both times it failed to start. I do not believe there is a problem with the safety cut-out.
Obviously there isn't much else I can check out on the water and it starts every time at home on the muffs.
What else might I check before I take it in and pay $$$ for them to try to trace a problem that probably won't show itself?
Any and all advice appreciated. Thanks...W

 

[rodbolt]

Re: Yamaha F115 Starting Mystery

have your dealer reasearch all the tech bullitens about hard/no hot restart.
I cant remember all the details but there is a few bullitens and corrective actions that can be taken.
occasionally heat soak can cause fuel vapors to exit the VST and collect in the intake tract causing an excessivly rich mix and hard starting when hot.
there is a cure if thats the problem.
next time it happens open the throttles slightly and retry. if additional air makes it start easier then your on the right track.
other than that you will have to have a fuel rail test guage and a peak reading multimeter onboard when its broke.

 

[ARCWINSTON]

Re: Yamaha F115 Starting Mystery

Thanks Rodbolt.
One thing I perhaps didn't make clear is that both times when it refused to start it had been shut off for at least 1 hour (while drift fishing).
I will try cracking the throttle next time as you suggest just to give the tech a bit more info and then it's off the the dealer I guess.
Thanks...W

 

[fish418]

Re: Yamaha F115 Starting Mystery

I am also having the sme problem, i can only get it started by going to wide open throttle and pullin it back real quick. if you hear anything let me know and i will do the same

 

[Taterchip]

Re: Yamaha F115 Starting Mystery

I am having the same problem. After running for awhile and a short stop, it will crank but not fire. It will re-start after about 5-10 tries in 15-20 minutes. It smelled at first, not exactly like gas or electrical but kind of like a diesel running on cooking oil. Wierd. Its happened twice in the last few months. I had mutiple other stops and re-starts on the same day without issue. Have not been able to troubleshoot anything except that there is no water visible in filter housing and primer bulb is tight. Any more suggestions would be appreciated. I am planning to carry a fuel pressure gauge and multimeter next time I go out to see if that reveals anything. I'll let you guys know if I find anything.