stopped running at full throttle....vapor lock?

[HotShot]

Hey All,

I have a 2011 thunderjet luxor....the Suzuki motor is 2011 DF 140.

So last year I was fishing in the Columbia and in the afternoon..."it was hot but I don't remember the temp that day"....I was running up river for another run when the motor stopped. It settled into the water and after waiting a minute or two I turned the key and it started....no problems the rest of the day or since. This year....two days ago I was again fishing on the Columbia. It was a very hot afternoon with the temp at 100 and the water temp was 72. I was again at high throttle running up river to make another pass and the motor cut out. It had been running fine all day. I tried to restart with it trying to fire a little but not starting. I started up the kicker and between it and the electric motor we fished down to the launch. I tried several times to restart but it would not start. I got home and waited until morning. it was 72 degress that morning. I hooked up the water and got in the boat. it started immediately. No problem starting several times in a row. I waited a few hours and tried it again. No problem, it started right up and ran great. My first guess when I was out on the river was maybe a fuel filter. But I had changed it this spring. I know they can go bad especially with bad gas so I kept an open mind. Well, I now believe it is the hot weather and the motor is vapor locking in the heat of the day when temps are well over 90. And especially with warm water in the lake/river.
So, what do you think....and what is a fix for this motor in hot temps so it wont vapor lock?
Thank you.

[Moonlighter]

I doubt very much whether the issue is a vapour lock causing the motor to starve at high revs. Not heard of that happening.

Vapour lock is normally an issue that raises its ugly head after the engine has been runnnig at higher revs and is then stopped, and then refuses to restart again after a short time.

What you have described is much more likely to be a fuel restriction somewhere..... i had a very similar experience a few years ago and it was a dirty load of fuel - changed the water separating fuel filter (Racor style), trash was evident. So ran a couple tanks thru and changed filter again. All good since then.

Some things to check -

- change your water separating fuel filter, and when you do, drain it and inspect for contaminants.

- There could be some trash in your fuel tank, that gets caught on the pickup tube screen filter at high revs - so when the engine stops, before long it falls off (depending on how hard it has been scuked onto the screen) and the engine gets fuel again and runs as expected.

- make sure your tank breather is not kinked or restricted anywhere. Blow thru it to make sure it is clear.

[Harper]

I would also check wiring, concentrating on the start switch, and ignition wiring. You have a 6 year old boat and motor. Things corrode, switches and wiring both. Connections loosen up, break contact with movement, lose contiuity when damp, regain that continuity when once again dry.

As Moonlighter said, not likely vapor lock. That's something that more often occurs after shutdown, due to heat soak.

[HotShot]

Thank you guys for responding to this post.
Yeah, I wondered about a filter. As it quit and would try to fire a little at first but still not start up. I find it fishy that it happened last year but at least it started right up and ran the rest of the day and in fact the rest of the year with no issues. I guess its coincidence that it happed again the same way but this time didn't start. Could be that my water separator was going bad then but still started back up....this time its going bad and decided to make sure I change it before spring time.
I will check all that you guys mentioned as well as changing out the water separator.
I had the service people do it last time...I think this is something I better do as if this is the problem I don't want to keep running it to the dealer twice a year to have it changed. Any good youtube videos you guys got on changing it out? Or pictures and tips on changing out the water separator and other fuel filters on the motor itself?

Thank you so much

[bill2452]

HS, I had the same problem with my 2011 175. The only difference was that all 4 of my idiot lights came on, then the motor died but would start right back up. It was definitely heat related and had a tough time convincing Suzuki that it was the ECU and it was caused by heat buildup. Here's the link and the troubleshooting I did. Never had another problem.
http://www.suzukioutboardforum.com/s...tor-stops.html
Mine is also on a 21' TJ. Must be fairly close to you, i live in Columbia City.

[Moonlighter]

Thank you guys for responding to this post.
Yeah, I wondered about a filter. As it quit and would try to fire a little at first but still not start up. I find it fishy that it happened last year but at least it started right up and ran the rest of the day and in fact the rest of the year with no issues. I guess its coincidence that it happed again the same way but this time didn't start. Could be that my water separator was going bad then but still started back up....this time its going bad and decided to make sure I change it before spring time.
I will check all that you guys mentioned as well as changing out the water separator.
I had the service people do it last time...I think this is something I better do as if this is the problem I don't want to keep running it to the dealer twice a year to have it changed. Any good youtube videos you guys got on changing it out? Or pictures and tips on changing out the water separator and other fuel filters on the motor itself?

Thank you so much

We are not talking about a water separating filter on the motor itself, but the one fitted in the fuel line between tank and motor. It is simply a matter of unscrewing the element from the filter head and changing it to a new one. One tip is to fill the new filter element with fuel before you screw it back on, this makes it much easier to prime the fuel system using the primer bulb.

[HotShot]

I bet it must be that filter then. Unless they changed it out at the dealer when I had it service "which I doubt cuz I don't remember that item on the bill"...it has not ever been changed out. I will have to find where it is located on my boat.
Hi Bill! Yeah I live in Redland just east of Oregon city 6 miles. Did you buy your boat at Siglers in troutdale? Also, do you know where they put your fuel separator? Where its located on your TJ boat?
I hope that is the problem. I looked at the wiring from the switch to the motor and didn't see anything that stood out. All seemed tight and clean. The venting tube looked ok and I blew through it into the tank with no obstructions.
There were no buzzer alarms or lights on the panel. It just up and died at about 5,000 RPM after running for about 5 minutes taking me back up river to start trolling again. It didn't sputter of cough, it was running great then just simply died. When I fish the river I run up and then we use the electric motor to troll down the river sometimes up to 2 miles. Then I use the big motor to run back up or to another spot. So, the big motor does get a lot of down time inbetween firing up and being used. I have been out a dozen times this year with no issues. just seemed weird and coincidental that it was very hot that day and this happened again like last years one incident.
Question....does the kicker motor feed off the lines before or after the water fuel separator? My kicker ran fine at higher RPM while using it after my big motor crapped out. It uses a quick connect that they installed on the stern of the boat by the kicker mount.

Thank you guys so much for your help on this!