900 zxi suddenly quitting at WOT

[dannogypsey]

I bought a used 1995 900 zxi..it seems to be ok mechanically except for a little gremlin. It ran good the first couple of times out, but the gremlin took hold!!!! After it warms up and is ridden for about 20 min. or so..it will quit suddenly at WOT (appears to rapidly starve for fuel)...after coasting to stop..it will restart immediately and run at an idle (5 seconds or so after coasting) It will idle no problem...but, as soon as i give it throttle or go to WOT from restarting, it will quit suddenly again ...I then restart it and the same process over and over all the way back to the landing (beats paddling). I took it to the shop here...Kawi Dealer/authorized repair facility...they said the carbs are good/clean/excellent condition, checked ignition...seems ok...reeds are good....ignition box is good...coils good...compression is good..about 110 each...they are as clueless as me. They think it is a fuel venting problem? I (and they) have put new plugs in it also. I am now mixing 40 to 1 on premix. Any ideas out there..I am a pretty good shadetree mechanic, but new to the jetski scene. All the mixtures on the carbs were set and adjusted by the mechanic..test ridden...failed for him too!!!

[Bryan Glynn]

I would say you probably do have a fuel system issue - You could try rebuilding the carbs, and make sure you checkout all the other parts lik the switch, vent on the tank, etc.

[bodean]

I have a Yamaha that did the same thing. Drove me nuts. Turned out the lanyard stop switch was bad. Worth a look.

Bodean

[dannogypsey]

Hey..thanks for the tips..I cleaned/blew out the vent line (used my air compressor), took the tank valve off and it seems good...clear..., I put on a large/clear automotive Fram Type fuel filter to observe the flow...Should it be full while running? If I shut off the selector for a few seconds while running..then open it to run position..it fills to about 1/2 full RAPIDLY....then it drops to about 1/4 full...even at WOT (running it out of the water) Is is possible to rig up an electric fuel pump and an adjustable fuel regulator to end the fuel flow nightmares? I also took apart and cleaned the lanyard kill switch..looked excellent/clean. I am going to take the beast out tomorrow...see what happens...Any other ideas that I might be missing?...Rebuild of the carbs will be the next thing if the fuel pump is a bad idea? How often do the carbs need rebuilding on these engines? ( I am a shedetree ski newbee) Also, where do you get the tamper proof allen wrenches to disassemble the pump bodies on the carbs? Do they come with the rebuild kits? I do not have a pop off pressure gauge...can i just put in the old springs..or do I use the lightest ones for this ski (stock 900)??? [img]graemlins/cwm3.gif[/img] [img]graemlins/crying.gif[/img]

[fairclothg]

I think I have a similar problem 1100 ZXI 99’…I replaced everything reasonable to think of… now I’m thinking it’s the fuel line or a vent issue… the only other thing is my ski runs very hot all the time.. but if I run it at 5500 RPM is ok just very hot but go WOT and it bogs down then dies off … it’s restarts but I don’t run it hard after that for the rest of the day. I was thinking vent because if I use about ½ a tank and take the cap off I get a suction..
Keep us posted.
Greg

[slag]

Greg, I think thats normal. My 900zxi does the same thing with the gas tank--use some of the fuel then remove the gas cap but its not a suction--its a pressure, at least on mine. Its enough to blow the cap off the filler tube after unscrewing it.

Aside from that, I have no problems with my zxi.

[Bryan Glynn]

No, suction is not normal - that means the check valv eis stuck. You should have pressure.

[slag]

there is no check valve on the zxi at least not on mine.. just a breather tube that is threaded up under the steering column

[Bryan Glynn]

I *think* it's part of the actual baffle assembly, part 59231-3001

[slag]

I've had my tank out and did not see it as part of the filler tube/baffle assy, but maybe i didnt look hard enough. In fact, I was looking just this weekend for it and couldnt find a check valve.

Bryan, can you answer my other questions in this forum about my 650 x2.

Thanks

Joe

[fairclothg]

Good info thanks guys…
I know what you’re talking about pressure or suction. IE I can tell the difference lol.
I’ve seen it blow the top off before but not after ridding but before when I’m getting gas and the heat and fumes had time to build up since the last time I was out. During my ride if I open the tank I get a suction sound. I’m not sure if it’s a check valve or just a vent but the book calls it a vent. The shop book calls to clean the screens every 25 hrs in the gas tank. I’ve never done it before. Plus the fact I was a used ski anything could have happened. So I guess I’ll try that next. My fuel filter never has more than ½ liquid in it.

[dannogypsey]

hey guys...After blowing through the vent line with the compressor (110 lbs), cleaning the fuel pick up screens and lines, new large fuel filter, new plugs, correct 40:1 premix, clean kill switch, checking it all out...it finally ran GREAT!!!! I have run about 3 tanks now...no problems!!! However, I do not get any pressure or suction effect in my tank now while riding. If i pop the fill cap after 1/2 a tank...nothing...no sound. The book says that there is a baffle assembly (Kaw website) under the cowl...I cut the vent line adjacent to the tank by the valve...there was a little plastic piece (gizzmo/insert?) inside of it...I tossed it...blew the line...reassembled it. It runs consistant from full tank to near empty..no leaning out. Hey, if it runs...who cares?...lol Anybody else have this kind of problem? How about putting electric fuel pumps with adjustable regulators on these rigs? [img]graemlins/oogle.gif[/img] [img]graemlins/cwm3.gif[/img]

[cbeastwood]

Guys,

Coincidentally, my 750 ZXI did something identical to this yesterday. While cruising at WOT, the boat just cut out. It would start fine, idle fine, etc.

I thought maybe I fouled a plug. I pulled the plugs and they were wet with oil. And the fuel filter looks to have a few more dirt particles in it than usual. I'm thinking I picked up some dirty gas.

Anyway, I remembered that about 15 minutes before the engine cut out, the boat took VERY LONG to get up on plane. Like it didn't have full power. I thought it was just because it was choppy water (never rode on chop before), but perhaps the lack of power had something to do with it quitting?

Ideas?

- Craig