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Discussion Starter #1
I have just got 2 new jet skis. One is a 96 Yamaha 760 wave blaster 2 it has been sitting for 2 years cleaned out gas on both and cleaned carbs and got it running but it won't clear out it is putting out a ton of smoke from oil is there a way 2 adjust or fix to much oil loding up the moter? And on the 97 kawasaki 1100zxi jet ski it runs the rpms go up by them selves with out the throtel being open ther is nothing stuck is it a leak leting air in and if it is how do u diagnose where it is leaking from or what else could it be?
 

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Well where to start....

On the blaster I have a question for you: Is this ski still oil injection and if not, what's the ratio you're running?

For the ZXi, it could either be an extreme lean condition or an air leak. I'm almost positive it's an airleak though. To find its location you're goin to need to pressurize the case and intake to a few psi and spray a soapy water solution on to it. Where the bubbles form is where the air is leaking from. This is easiest to do with the engine removed, it's gonna be pretty difficult to get to some of the possible leaks with the engine still in the hull.

Best way to pressurize the engine is to place pieces of rubber between the throttle body and intake manifold, and then another piece between the exhaust manifold and the cylinders. Just use a small tire pump to put about 10 psi into the engine once its sealed.
 

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OK well oil injection pumps wear out eventually... It could simply be that, but usually those pumps stop giving enough oil when they die. Is it an adjustable oil pump? It would have a linkage or cable going to the carbs throttle if it's adjustable, or variable I guess is a better word.

What kind of oil are you using? How old is the oil? How rich is your carb set? Any of those can also cause excess smoke from the exhaust.

That being said, also remember that it is a 2-stroke and some smoke should be expected. If you're not seeing smoke while on the trailer then you're not getting enough oil mixed.
 

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Discussion Starter #5
The oil is over 2 years old and the brand not known just got these skis. Also there is no adjustments and no likage 2 the oil plate on top of the carb.So the old oil will cause it smoke more? Oh yah I was talking 2 the sbt techs and they said that is normal for them 2 smoke after they sit that long and it would take it a little while for it to clear out on the water but if I ran it for a while on the trailer and cleard it out wouldn't that do the same thing as riding it? And if I did how long would I have 2 because I let it run for about 10 minutes and tride to get it 2 clear out. Earlier you said that they smoke some but it smokes the hole neighborhood out and my other skis don't smoke like that.I'm starting 2 wonder if it might of been water because we turned on the water hose first and your not suppose to entale the engine is running now I know that but live and learn right! Maybe that was the extra smoke?
 

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Not likely on it being water. The reason you're supposed to start the engine first is so that water can't back-up into the engine and cause it to hydro-lock. 2-year old oil could cause it to smoke alot especially if it is the wrong type of oil or it was poor quality. Oil degrades over time, and some 2-stroke oils smoke more than others.

How does the engine run? Does it bog down or anything? Is it hard to get to high rpms? Does it hesitate when you open the throttle? If any of those answers are yes then you have a problem and it could be too much oil delivery. If you don't have any of those symptoms then I don't believe anything is wrong. Too much oil will cause problems like those...

I have an old kawi 750ss and it smokes my garage out, makes it look like i started a fire in there! It's normal though... See those things tend to run a little rich on oil when idling anyway. And that's supposed to clear out once you get going.
 

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Discussion Starter #7
Yes it bogs down i can only get about 1/2 throttle if lucky and if i very slowly pull the throttle and then hold at 1/2 it clears out and runs smooth and normal amount of smoke but then hit it 2 full open it starts barreling out clouds of smoke and bogs down and won't pick up rpm all the way.
 

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Did you rebuild the carb or just clean it out? What are your carb settings, as in how many turns out on the highspeed and lowspeed needles?

It's certainly running way too rich, could be rich on oil or gas...

Sorry to keep asking so many questions of you! I'm trying to run you through the troubleshooting of this problem. I've already guessed at the most usual issues and those aren't the cause soooo..... Now we're down to troubleshooting and we'll find the answer that way...
 

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Discussion Starter #9
I just cleaned it out but I didn't pull the needles out I'm going 2 do that next and then I will let u know the settings on the needles on this model how can u tell where the high speed and the low speed? Is one higher then the other etc......... Also don't be sorry I understand I work on cars for a living I'm just not familiar with jet skis some things are the same and the basics but anyway thanks for your patience and help!
 

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Yeah, the highspeed needle will be the one towards the top of the carb. You really should rebuild the carbs, they are pretty sensitive to stiff diaphrams and old n&s combos. The needle lifts off the seat based on the pressure exerted by a diaphram, if that diaphram is stiff then the needle will either not lift off or stay open.
 

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Discussion Starter #11
when I pulled it apart the diaphrams they are soft not stiff but if u could tell me the settings of what the needles shoud be set at? I want 2 try that then if that doesen't work time 2 rebuild.Thanks again! Talk soon!
 

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Stock settings:
Low Speed – 1-5/8 +/- ¼
High Speed – 3/8 +/- ¼

Those are the number of turns out from fully closed. If that doesn't work then take the carbs back apart and examine the needle & seat. Look for a ring around the needle or a scratch in the seat. Anything like that will cause problems. Personally if the adjustments don't fix it, I would rebuild the carbs. Sometimes a simple cleaning just doesn't do the job!
 
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