SX/SXi/SXi Pro The ski gave up, I won!!!!

[Captain PegLeg]

I have been having problem with my 750 sxi boggin out and dying on the low end (under half throttle). It runs amazing on top, speed, power everyhing on top. But down low it bogs out and dies. It only does it on the water. You can go slow but you have to do little wide open throttle blurps. It will idle all day through the no wake zone, but half throttle and under it bogs and dies. It will fire right back up. It sounds perfect on a trailer. I am sick of working on it and nothing makes it better. I talked to a mechanic for kawi watercraft and he said he will fix it for me on the side at his house to avoid the huge shop rate at the dealership. Here is a list of stuff i have tried:

New top end
New crank seals
rebuilt both carbs
new kill switch
new fuel lines with new filter
replaced a full tank of gas to fix a cracked filler hose
3 different head gaskets (all new)
new ignition


I am out of ideas... the prob all started when it ran out of gas and the iginition started backfiring. Replaced the ignition and the backfiring stopped. But then i can't get this damn bog out. When i replaced crank seals i sealed everyhting up tight. I even put the stock head back on... NO MORE IDEAS. Its nothing motor or electric cause it runs so good up top. Is there some thing i can check in the carbs that i may not know about?

 

[tor*p*do]

WOW, sounds like a bad case of the Kawi curse :skull2:

look on the bright side
you can
sell it on eBay and then pick up a SN as a backup ski :Banane09:

 

[BruceSki]

did you check out your reeds?

 

[Captain PegLeg]

I actually have a square hull i am building. This thing is to damn clean to sell. It honestly looks like something out of a museum! HAHA! I'll keep it cause i couldn't get what i would like out of it, ad its just to clean i'd rather keep it for friends and stuff.

Yeah... i have checked the reeds, that is the first thing we looked at when the prob started 4TH OF JULY LAST YEAR! Thats how long i have been fighting this thing.

 

[BruceSki]

did you try swapping an entire electrical system out of a running ski?

 

[Captain PegLeg]

I posted it up here asking to borrow a known good one but no one ever let me. I figured if it was electrical it wouldn't run good in any of the rpm range.

 

[BruceSki]

those 750 stators are very touchy... once they get hot they will act real funny...

that ended up being the final straw for me after switching a couple stators out on my old 750. it would run good for a while then start doing funny things like that. ex: idle only, no rev under load. my problem was it would crank right as you let off the start button though.

sounds like you are at your wits end with it.

hope your buddy can figure it out for you. let us know what it was if he does.

good luck

 

[Captain PegLeg]

Thanks alot man.... I am just tired of throwing money into it and it not fixing the problem. So i'll make sure it gets done right. Plus, when it doesn run right, i will have like a brand new ski with all the parts i have put on it!

 

[sflsurfrider]

your problem sounds carb-related.

does run any better if you choke the carbs 1/2 way?

 

[st.clair.jetski]

my buddies RN was doin that kinda of thing last year and it ended up being his jetting setup it would rip top end but bottom end was real boggy adn would stall out wen u tried to slow down from rippin or if u pinned it to take off u had to give it blasts of throttle until it got up on plain he ended up ein way to rich and had to turn the pilot jet almost all the way in till we got the rite jets ordered

 

[Crab]

check for plugged water box.

 

[WFO Speedracer]

Sounds like a pop off issue to me,the kehins are really touchy regarding pop off pressure,just like a Mikuni you have to have the correct spring in there or its not gonna work.

 

[cmeripper26]

Def. a popoff issue if you changed the stock airbox and put on adapters with aftermarket flame arrestors. With the stock carbs you cannot use aftermarket flame arrestors without re-setting the popoff pressure. This is more than likely the case if you are running aftermarket flame arrestors.

 

[Captain PegLeg]

check for plugged water box.

How should i check this...

Def. a popoff issue if you changed the stock airbox and put on adapters with aftermarket flame arrestors. With the stock carbs you cannot use aftermarket flame arrestors without re-setting the popoff pressure. This is more than likely the case if you are running aftermarket flame arrestors.

I am running aftermarket flame arrestors. They were not a problem last year before this problem started. I will try running the stocker this sunday and see if it makes a difference.

 

[Captain PegLeg]

my buddies RN was doin that kinda of thing last year and it ended up being his jetting setup it would rip top end but bottom end was real boggy adn would stall out wen u tried to slow down from rippin or if u pinned it to take off u had to give it blasts of throttle until it got up on plain he ended up ein way to rich and had to turn the pilot jet almost all the way in till we got the rite jets ordered

Sounds kinda like my problem.

 

[Captain PegLeg]

cmeripper26 do you think if i put the stock air box on this prob should go away? Also, anyone know the stock air/fuel settings? I will put this ski back totally stock and check it. The kawi has like limiters on it to only allow the screws to turn a given amount. They have never been changed more than just 1/4 of a turn. (that is about all the limiters allow you to do.)

 

[N3vrSat1sfied]

stock screws is 5/8 out on high and 1 1/4 low i think might be vise versa. I have a aftermarket flame arrestor on mine and never changed pop off (but i bought carb and filter together) It could be a spark problem with stator i had something similar but i couldnt narrow it to certain throttle but the ski would run great untill it got hot then it would quit the stator was bad.

Also when you set the carb screws make sure the screws come out and the low isnt broken in the carb.

 

[cmeripper26]

if those are the stock carbs without any tuning done to the carbs, the main thing being the popoff pressure, then im going to say that your problem is the aftermarket flame arrestors on the stock carbs. What tends to happen is you can run those aftermarket FA's on the carbs for a little run time without noticing the bogging out on the bottom end, but after a little ride time you will begin to see as you try to jump on the throttle to whole shot or pick yourself back up right on long, fast turns after getting off the throttle for a second you will see a little delay as you womp on it before you get throttle response, it will bog down and after a second you will finally get throttle response. If you are getting these symptoms with your ski, Try putting the stock air box back on the carbs and go back to the stock settings on the carbs. Let me know if this works out.

 

[Captain PegLeg]

if those are the stock carbs without any tuning done to the carbs, the main thing being the popoff pressure, then im going to say that your problem is the aftermarket flame arrestors on the stock carbs. What tends to happen is you can run those aftermarket FA's on the carbs for a little run time without noticing the bogging out on the bottom end, but after a little ride time you will begin to see as you try to jump on the throttle to whole shot or pick yourself back up right on long, fast turns after getting off the throttle for a second you will see a little delay as you womp on it before you get throttle response, it will bog down and after a second you will finally get throttle response. If you are getting these symptoms with your ski, Try putting the stock air box back on the carbs and go back to the stock settings on the carbs. Let me know if this works out.

Sounds like my symptoms... but sometimes it will die. Not just bog. I will try the stock intake and see if anything changes. I will let you guys know on monday.

IF, i put the stock intake on and the syptoms still persist is there anything i can check for at the water? I just want to get this thing right so i know if i need to ride it, i can.

 

[Captain PegLeg]

Anyone have a known good stator i could borrow to try out?