Could this be the reason for my lack of WOT and bog? - SOLVED!

[E350]

Last weekend at the end of the day, I noticed that the stock 61x 701cc in the FX-1 wasn't running as well as it should.

Today it was noticeably worse. At our "private beach," I pulled the hood and looked to see if the hose clamp connecting the muffler to the hose going to the water box had come loose, because I had that happen before and the exhaust gasses leaking into the engine compartment starved the carb from oxygen. It wasn't loose. So I put the hood back on and it was better so I road some more but had to limp back to the boat launch.

I was taking the carb off so I could take it apart to check the internal filter and, for the first time, I noticed this little hose was off.



Sure enough, although it is little, it really spews exhaust out. So, could that be it?

The original oem constant tension clamp is way too loose to do anything, but I think I have some constant tension clamps that size so I think I will forget about the carb for tonight and ride tomorrow and see how it goes.

Is water supposed to come out of the head into that little hose and then go to the muffler? If so no water was coming out when I just started it. But then again the ski is not in the water...

 

[WFO Speedracer]

Yes water comes out of the head and goes to the pipe and yes if its not in the water it won't pump any water out of it, I have worked on several where the 6mm bolt on the stock pipe had backed out and had similar running issues. You just just see it a the top left corner of the pipe in that recessed area

 

[E350]

Thanks WFO!

Great photo! I will keep aware of that bolt as well.

Prefer to put off minor carb surgery if I can for now.

 

[WFO Speedracer]

And tyes if that hose is not connected to the head exhaust will come out the hose and water will go into the hull. I DON'T THINK YOU CAN EVEN SEE THAT BOLT WITH THE PIPE ON THE ENGINE , YOU JUST HAVE TO FEEL FOR IT.

 

[E350]

Fingers crossed for tomorrow's ride!

 

[Big Kahuna]

Just use a zip tie if you need.

 

[WFO Speedracer]

Yep thats a barbed fitting , put a small zip tie on the hose below the barb and it should not come off again.

 

[E350]

Since it is an exhaust clamp and oem was metal, this is what I had and this is basically what I used (see in photo above).

 

[WFO Speedracer]

That should work , not a lot of pressure on that little hose

 

[E350]

Road great at first today, then no high rpm, then had to be towed back by my wife to the boat launch.

The ski would start idle then die under any acceleration.

To get it on the trailer I primed it and it jumped on the trailer.

To clear the water box, I primed it and it ran high rpm to clear it while I punched the throttle.

Obviously some sort of a condition leading to fuel starvation.

ONE VOTE FOR A PRIMER AS A DIAGNOSTIC DEVICE!

Removing carb now. Will check tank vent, fuel filters but all of those are new this year.

 

[WFO Speedracer]

My bet is internal filter in the carb is clogged up or a blockage in the fuel selector valve.

 

[E350]

The internal filter in the carb was not blocked (it had a little debris in the end but nothing photo worthy).

The check valve is working properly. When I suck in it lets air in without restriction. It won't let me blow in it.

The Yamaha fuel filter is flowing without restriction, which I assume means that the little triangular screen filter I have at the tank is flowing without restriction.

I still haven't checked to see if the tube fell off the pick up port in the tank but I will look tomorrow.

The ski starts with primer, gives me two good WOT on the trailer and with the third WOT it bogs and then dies.

Any suggestions guys and gals?

 

[Big Kahuna]

Pulse line still attached?

 

[E350]

Yes, thank you, I even detached it and reattached it with a new zip tie at the carb.

 

[WFO Speedracer]

What does the main diagphragm look like ?

 

[DylanS]

Time for carb surgery

I’ve also seen large particulates build up in those Yamaha fuel filters that settle to the bottom then once fuel gets flowing they get pulled up and block off almost all flow through the filter but seeing as you have a filter before the filter id bet that isn’t your issue.

 

[WFO Speedracer]

I know you said you checked the one way vent on your gas tank, what is it hooked to, have you checked the line that hooks to the one way valve hooks to to make sure it is venting properly
?

 

[Storbeck]

How do the fuel lines themselves look? A crack in the fuel line to the carb can cause weird issues because it sucks air when the carb is pumping but still seals good enough to not leak fuel, I had that happen once. Basically the crack in the line acts as a one way valve.

 

[WFO Speedracer]

If you don't find anything obvious do this test, remove the return line from the carb, plug the return nipple on the carb, you can use a piece of hose with a bolt stuck in it if you cant't find a cap or plug, now blow into the return line as hard as you can and plug it, now take a spray bottle with water and dishwashing detergent in it ansd spray everywhere the fuel lines connect, around the fuel cap and around where the pickup attaches to the fuel tank as well., if it is leaking somewhere it will bubble up, you also want to make sure the fuel cap is sealing and the fuel pickup where it mounts to the tank isn't leaking. IE ; the whole system needs to hold and maintain pressure.

On Seadoos I had a cap that I drilled and threaded for a fitting and you could pressurize the system and install a low pressure gauge to see if it leaked down or not, you could do that here also but I gave you the simple way, we had to do fuel pressure test when we did all the fuel tank recalls.

 

[E350]

Thanks for the suggestions guys. Keep them coming. I will try all of your suggestions this evening after work.

With help here, I have been able to fix every issue on our skis so far, so I know I will be able to figure this out with your help.