[Socal750sxi]

Got issues!

Bone stock! Runs fine out of water reving it, starts fine and idles fine. It dies just before plane consistantly (just before you try to stand up) in the same part of the powerband. I can feather the throttle working it until it gets past the dead spot and then it takes off .....stay on the throttle and the top end runs wide open perfectly. Once you let off the throttle it reverts back to that same flat spot..(just before plane). My thought was the cdi so i figured i would put the aftermarket one on to give it more power since i wanted more top end anyways and if it didn't fix the problem i would start replacing other things that might fix the problem. The MSD Enhancer was installed and the problem got worse?? All over the powerband. Could this be the Coil??? That was my next guess. Could it be that water temp sensor??

Any help would greatly be appreciated.

Thanks in advance.

 

[p10sdad]

Try jetting it first. If you can feather past the flat spot, check your low and mid jets

 

[Socal750sxi]

Even if it is stock? If it's fuel related maybe the fuel filter might be an issue?? Is that in the tank? Anyways, thank you very much for the suggestion. I will take a look at it, maybe it needs to be cleaned out or something..

many many thanks.

 

[p10sdad]

I don't know if there is a fuel filter in the tank on 750, on my 550 it's mounted on the right hand side just in front of the carb, my 800 is covered and tucked away, but I'm planning on going this next week if the weather holds up, so I'll look and let you know where that one is at. It shouldn't be the filter at medium speed, that should be more a high speed deal, but it's worth looking at. Yeah the jetting can be an issue even stock. Check how many turns out it's supposed to be vs. what you have. Someone along the way might have change it a quarter turn or so, and a quarter really matters on these. Let me know what you find, I have some other ideas too

 

[p10sdad]

Why your looking, blow all your fuel lines out, and make sure the one on the left hand side of the boat is clean. Thats the one the that comes off your jet pump, and shoots water out the side. We have "mud bees" I'm not sure exactly what there real name is, but they like to get in there and clog that hose up.

 

[Socal750sxi]

That one that sprays out the side? Would that cause that temp sensor to open if it's not spraying? I'll check it out. It sure feels like electrical to me but I will definately look into clearing out the fuel lines and adjusting the carb screws. Do you know how far they need to be turned out? Can the Temp sensor be disconnected if it is faulty? Those things are caish. Heading out this weekend to the colorado riv so I'm going to exhuast all options.

Thanks for the ideas

 

[p10sdad]

Yeah, if your standing behind the ski, there will be a little rubber piece on the front left of the ski almost straight down from the hand pole. it has a hole about the size of bb. That has to have water coming out of. As for jets I'm not to sure, but I think my 550 was 1 5/16 high, and 1 1/16 low and 15/16 for the pilot, and I just looked in the manual on my 800, and they don't give specs. Anyway I hope something helps.

 

[Socal750sxi]

Lets revisit this. Just got back from another outing and it's still doing the same thing. Sometimes worse than others. Seems like the longer we run it the worse it gets. A month ago, i tweeked the upper and lower carb screws (they only go half a turn) wide open on all four ..counter clockwise. It got worse. Then i left the bottoms half way and opened up both the top ones and it ran pretty good with very little hesitation for almost 3/4's of a tank and coming back in from that ride it got horribly worse. I couldn't get it to plane at all so i drug myself at a very low speed the rest of the way and now the problem is back. I'm going to order a rebuild kit for the carbs as i have now concluded that it's not electrical. I have blown out all the lines including the coolant pickup line coming from the pump. Coil has been replaced.

I do have 1 question for you pro's out there. Maybe the problem has been right in front of my face everytime when i fill this thing with gas??? Maybe i'm just wishing up a dead dogs ya'know? Came home this past weekend and filled my skiis up with leftover fuel while unscrewing the gas cap of this sxi curiosity was kicking in. I have had a crack in the fuel cap going right down the middle almost two inches long that has been there forever but has getting a tiny bit worse with time. So i started thinking to myself is this thing leaking air or maybe even letting water in? So i blew air into it and it came out pretty easy?? I see breather tubes on the gas tanks of these things could the gas cap be causing me these problems? Could this ski run right if the gas cap was off...theoretically? Assuming water wasn't getting in. Or is rebuilding the Bottom end of the carbs the way to go? Thinking of cracked seals in the injection area.

Thanks guys

 

[p10sdad]

Well I'm not a jet ski "pro" but no it would not run right if the cap is off. It builds pressure in there. Sounds like a gas cap and you'll be good. Besides you don't want water getting in your tank anyway, so it's not like a shot in the dark, you actually need one