1997 750 ZXi running problems. Bad gas, water?

[Mr Bigins]

Hi, I've been taking my ski to a dealer over the past month with various problems. I got it back after summerizing it, and it ran great but it was taking in water and it turned out to be an intake hose for cooling. I then filled it with 3g of gas at BP and took it out. It ran like crap. I gave it throttle and it would just bog down and eventually kill.

I took it back to the shop and they took the carburator apart and added new pins and diaphrams, along with gaskets. They also removed the gas from the tank saying that it was some of the worst gas they had ever seen. They saved some in a gatorade jug for me and it was even darker yellow than the gatorade that the container normally held when new. I went to BP and put some in a fresh clear container and it was very dark yellow. Gas, as you know, is almost clear in color.


Adding new gas, it ran great at the lake for about 15 minutes. Then it started bogging down like it had before, but it wouldn't kill. I added some seafoam. Taking it out of the water, it would start and run and seemed to always get out whatever it was from holding it back from opening up and going. I'd put it in the water only for it to work 4-5 minutes and it would bog down again.

Talking with some people, they say it sounded like water was getting in the fuel somehow. Because if I take it out of the water, it clears out after running, and then stops working properly after it's been in the water running for a bit. Makes sense.

But this gas I got was really bad, was there enough bad gas(pints) left in the tank that it still affected it?

How much does it affect things with there being even a little water in the bottom of the hull? Can that cause something like this? When the intake hose was ruptured, there was a lot more water in the hull, but it still ran great. So I don't think so.

Or could water be getting into the line somewhere as you ride it? What do you think is causing this to happen?


Taking any questions. Thanks!

[Technical Support]

Re: 1997 750 ZXi running problems. Bad gas, water?

How does the gas cap look? cracks, bad seal?

[chase377]

Re: 1997 750 ZXi running problems. Bad gas, water?

I had a problem similar to this one time and it turned out to be a bad fuel tank vent. It would run fine out of water but when you put it in water it would do great for a couple of minutes. A small amount of water inside the hull should not cause any problems. Hope I was helpful.

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

I'll have to check TS thanks. So it sounds more like water or condensation is getting in somehow? I want to add that I replaced the fuel filter(which it needed). And that when it does bog down now out on the water, it still runs and I can go 10mph but that's it.

I had a problem similar to this one time and it turned out to be a bad fuel tank vent. It would run fine out of water but when you put it in water it would do great for a couple of minutes. A small amount of water inside the hull should not cause any problems. Hope I was helpful.

You were, thanks. A bad fuel tank vent? Never heard of it. Any way to look into or replace? If it's an air vent to let air in, can I test it by loosening the gas cap on the water when it bogs down to test to see if that's what it is?

Just remember that it isn't fuel injected and doesn't need back pressure to run properly.

Thanks you guys, I'll look at the gas cap and seal.

[chase377]

Re: 1997 750 ZXi running problems. Bad gas, water?

yea, you can loosen the cap to see if the vent is bad. When the ski is running the fuel is sucked from the tank creating a vacuum there for if the tank vent is not working properly it will starve the ski for fuel causing it to bog. It usually takes a few minutes before the ski starts to bog if the tank vent is bad. They are very inexpensive and easy to replace. Its located on top of the fuel tank itself and it is a round white plastic piece mounted in a line coming from the top of the tank.

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

yea, you can loosen the cap to see if the vent is bad. When the ski is running the fuel is sucked from the tank creating a vacuum there for if the tank vent is not working properly it will starve the ski for fuel causing it to bog. It usually takes a few minutes before the ski starts to bog if the tank vent is bad. They are very inexpensive and easy to replace. Its located on top of the fuel tank itself and it is a round white plastic piece mounted in a line coming from the top of the tank.

Thanks. I'm looking in the shop manual and I'm not seeing a fuel tank vent anywhere. Isn't a fuel tank vent a piece of hose leading nowhere? If so, would this piece be inside that between the hose and the tank?

I'll see if I can take a couple pics.

[chase377]

Re: 1997 750 ZXi running problems. Bad gas, water?

I'm sorry kawasaki calls it a check valve. It's a in line filter looking thing, it should be white and round, its pretty small. Sorry for calling it the wrong thing.

[chase377]

Re: 1997 750 ZXi running problems. Bad gas, water?

Yea the "check valve" is located in line on a hose that goes from the tank to under the handlebar pad.

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

Ok. I'm going to have time this afternoon to work on it. I found the hose and started to disassemble the top(the hose wasn't under the handlebar because of space) and should be able to check that today. I want to be sure it isn't plugged somehow. The hose to the tank is hard to get at, I'm hoping that I can get directly over it after disassembley.

Then you said the check valve is right near(on?) the gas tank? Is it in the line then, or on the tank somehow?

If you remember? Thanks for all your help.

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

I found the piece I think(it has to be).



It looks ok, but should it still be replaced? The hose looks ok and nothing seems to be blocking it. However, before I removed the hose from the tank attachment, I blew into the hose which was under the handlebar(out of site) and it seemed plugged. So now I'm going to try and connect the hose and blow againg. If it's plugged, the next thing would be the connector to the tank in which there's alot more work to that with how much is connected.



This is mine. How do you take off the very top part that rises above the handlebar(in purple)? I have it all somewhat apart and I'm thinking of giving it a full detail job inside and out. What's a good degreaser that I can get from a store so that I don't get price gouged from an auto store?

Or the best way to clean the inside of a hull?

Thanks again!

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

Do I still want to replace that part? It looks ok to me. I drained the gas and ran it al out. Ran some good gas though it a couple times now.

So it's just that piece that I'm wondering about.

[Mr Bigins]

Re: 1997 750 ZXi running problems. Bad gas, water?

It also seems to be getting stuck when in low end. I'll run it in the water just fine with full throttle. But after I slow it down, sometimes it does not want to open up again when throttle is full. Instead it bogs down and I have to remove it from the lake and run it a bit again before it opens up again.