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Discussion Starter #1
I just picked up the above ski and have already pulled the carbs off it.

Back story: my wife and I bought this from a friend, and have ridden it several times over the years on vacation when they bring it up. This year it suffered from a severe lack of power and throttle response. It starts up and idles just fine, but full throttle from zero leaves it looking at you like "you want what??" And plateaus around 4000 RPM. It then slowly work up to 5000, then jumps up to 6000 and maxes out around 40mph.

My initial thought is that it needs a carb rebuild, which I plan to do. I'm now wondering if there's anything else I should look at while I have the carbs out. Fuel pump? Reeds?

In trying to diagnose what might be wrong with it, I opened the author/spark arrest or box and found that two of the 3 arrest or tubes had fallen apart and were rolling around in the box. The 3rd tube was just completely missing. I pulled these pieces our, and fished out and small pieces that were sitting on the carb slide. I'm a little leery that some may have dropped in, but hopefully they got sucked in and blown out the exhaust. I do plan to get new tunes as well.

Again, is there anything worth checking while I have access to the intake side of things that might be causing the lag on the bottom as well as lack of top end?
 

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Kit the carb with keihin kits. It's a little pricey, but worth the money. Replace the oil injection lines, and prime the system. I would hook the carbs up to a small can of 40:1 premix until the lines from the pump to engine/carbs get primed.
Document how many turns from seat each mixture screw is for each carb, and return it to that exact setting. Reeds are probably fine. Look at the fuel lines and make sure they are still tight. Might snug up the zip ties some. I'm sure they are not tight anymore.
Check the condition of the pulse line, and make sure it is tight on the manifold.
 

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Discussion Starter #4
Kit the carb with keihin kits. It's a little pricey, but worth the money. Replace the oil injection lines, and prime the system. I would hook the carbs up to a small can of 40:1 premix until the lines from the pump to engine/carbs get primed.
Document how many turns from seat each mixture screw is for each carb, and return it to that exact setting. Reeds are probably fine. Look at the fuel lines and make sure they are still tight. Might snug up the zip ties some. I'm sure they are not tight anymore.
Check the condition of the pulse line, and make sure it is tight on the manifold.
Do you have recommendations on where to get a carb kit?

I've also seen you mention a couple times now to replace the oil injection lines. Is there a specific tubing to use, or will a standard rubber tubing work?
 

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Use Tygon small engine fuel line 7/64 id should work, but double check with a piece of yours, and secure it with 4 inch zip ties. Most hardware stores, and small engine shops carry it in bulk.
You can try jetski parts, or scour ebay. Sometimes they will show up cheap.
 

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Discussion Starter #6
Thanks! I'm sure I'll have more questions as the ski is currently 2.5 hours away, and I'm trying to get everything prepared at home as availability of parts is limited there.
 

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Discussion Starter #8
Dumb question, but what do you do with it? I've dealt with old snowmobile and motorcycle carbs, but this is my first foray into PWC carbs.
 

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Attach the tester to the fuel inlet, plug off all other ports, submerge the needle in wd40, pump up the tester until the needle pops, and record the pressure. They all need to match.
 

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Discussion Starter #10
I wanted to follow up on this a bit.

I pulled one carb apart, and it looked spotless. Due to time constraints, I wasn't able to get into the other two before we hit the road back to our vacation place. I pulled the reeds and one set had a gap between it and the cage, so I flipped the reeds. Another set of reeds had a chunk from the flame arrestor tube in it. I removed that. The biggest thing I found was that the #1 and #3 spark plugs had terminal issues. Both of them had terminals were stripped and stuck in the boot, so when you pulled the plug wire off, the terminals went with it, meaning there wasn't very good contact.

You can see in the picture that one plug wasn't firing at all. I pulled the stuck terminals out and replaced with new plugs. I'm HOPING that this was the actual problem. Unfortunately the weather didn't cooperate, so I didn't get a chance to put it all back together to test it out.

FullSizeRender (1) by Jeff, on Flickr
 

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Don't flip the reeds. it will stress them, and poss. break. The reeds can have up to a .001 gap and still function properly. Since you have a broken one, I would opt for a set of Boysen reeds. Constant high rpm is what chips the reeds as they flutter against the cage. After market reeds handle this a little better, and carbon fiber like the Boysen pro series handle it very well.
Plugs look pretty decent, considering what was going on.
 

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Discussion Starter #12
Flipping the reeds was more intended as a troubleshooting technique. If things smooth out, I'll replace them this winter or next spring. As there won't be much riding between now and then, I'm not overly worried about it.

I do like the color of the 2 plugs that were actually firing. Hopefully, that was actually my biggest problem; only running on 2 cylinders.
 

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Discussion Starter #14
She runs a whole lot better on 3 cylinders. Had a fairly calm day and saw 60, and almost 65 out of it.

It's out of the water now, most likely for the season. I'll be ordering new reeds, gaskets, and flame arrestor tubes over the winter.
 
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