Gas not getting to carb

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I think there might be bigger problems now. It turns out the carburetors are not the problem with the flooding happening. What I think is happening is that the carburetors are pumping fuel really well but when they try to put the rest of the fuel not being used back into the tank, it can't. The line for the overflow seems to be underwater. So I need to figure out which line is actually for the overflow. But the most scary problem is that the engine is not flooding with the gas oil mixture we put in the tank. It is mostly oil somehow. With the oil tank there is still a line connected to the bottom of the engine. I was assuming that just lubed the gears down there but I think it is somehow making it into the engine. And it's no small amount because it floods the engine with it. Maybe the oil mixer is still there but I thought it would be somewhere between the gas tank and carburetors.
 
You have bad inner crank seals if it’s flooding with oil.

You will have to replace the crankshaft.
 
With how it is normally suppose to be set up where the oil injector is a part. Would it just put any exess oil into the crankcase for the gear or would it only put it in to a certain level. Because how it is now just would fill it with oil. Since it is just straight connected to the oil tank. This is only the second jet ski I have ever worked on. And I'm used to four strokes that's why I would like to think there is a level for the oil.
 
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The oil injection and the rotary gear bath are two separate systems that feed out of one oil tank.
The oil injection system injects a small amount of oil into the intake manifold.
The rotary bath is just a gravity fed sump in the middle of the crank case. If the inner crank seals fail they let oil from this sump into the lower crankcase that is connected to the pistons and cylinders.
 
Maybe it is still possible there is the oil injector. I just thought it would put the oil in the carburator not the manifold. And I do find all this oil from the manifold. It’s just enough oil to make the engine barley run or not run. There is 2 hoses connected to the oil tank currently. 1 is on the top of the tank and leads to the back of the engine where the exhaust manifold is. which I would think as an overflow but nothing has appeared to go through that line, or at least not a lot of it. The second one is connected to the bottom of the oil tank and leads under the carburetors. I’m just hoping for the best because I imagine replacing a engine in there isn’t all that fun. Sorry if I repeat too much just trying to make sure I state everything.
 
No, both hoses you described are to the rotary gear oil bath.
If the oil injection was still connected you would have a 3rd hose coming out of the oil tank to a filter then to the oil pump. From the oil pump you would have two really small 3/32" hoses going to the intake manifold.
 
Joey White said:
I’m just hoping for the best because I imagine replacing a engine in there isn’t all that fun.
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hope for the best plan for the worst.

also replacing an engine is extremely easy. once you get to know the ski and where everything goes it will take you less than an hour to pull the engine and about the same to put one in.
 
I'm not sure how I would pull it out actually. Engines aren't that light. That's the only thing I would have trouble doing.
 
I have seen several people who just pull the motors out by hand. They are only about 50pounds.

The official way to pull the motor is outlined in the manual. They explain how to take two old spark plugs and weld washers onto the top of them then use the washers as hooks for an engine hoist.

I personally don't own a welder, but found a local machine shop who gladly took 20 dollars to do this for me.

Honestly in my opinion doing the mechanical work on these things is a lot of fun. It's the electrical stuff that drive me nuts.
 
mikidymac said:
You have bad inner crank seals if it’s flooding with oil.

You will have to replace the crankshaft.
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Going back to what you said. Do I have to replace the whole crankshaft or is there just seals to replace. Because the problem has been narrowed down to something in the engine is leaking oil to the cylinders. If I have to replace the crankshaft it’s probably just cheaper to get a new engine.
 
its the inner seals that have given out on you. everything on the crankshaft is press-fit onto it and you will be unable to replace the inner seals without basically going to a machine shop and getting a full crank rebuild and balance.

This best route for this situation is to go over to SBT and order a replacement and send back your core to save you the money.

It's definitely cheaper to buy a new crankshaft (around $300) then a whole new engine (around $800) The question then becomes what shape is the top end in? if your top end is in great condition then just get a crank. if the top end is on the lower side of compression and maybe on its way out, you may benefit from just replacing the entire engine. The added benefit of this route is if you buy a "premium" engine you will get a two-year no-fault warranty.

It sounds to me that you guys just want a jet ski to bang on and aren't all that interested in working on it. If that is the case then just buy a new engine and get that warranty. This way you can just beat the hell out of the thing without worrying about it.

I can't say that I don't wish I had taken that route on my XP. It was the exact opposite issue though. The crank seemed in good shape so I got the top end rebuilt. 12 hours later the crank seized and destroyed the top end on its way out.
 
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I know I can get a better working engine for under 300. It’s not new but it’d work. I just want to keep this seadoo at least because I have the title. Also I don’t know how good the top end is. The pressure gage we got to test it’s compression is not relabel.
 
Defiantly wouldn't have warranty on it. It would just be from another jet ski. I don't want to pay for a even $600 motor. I don't really want to spend much.
 
Well if I can find out if the top end is good I'll rebuild the bottom end. I just need to find someone who has a reliable compression gauge. Also it has this head not sure how much that would up the compression.
1568423017193.png
 
Something to consider before moving forward

Matt Braley said:
I have used pipes and carbs on the 717/720 to get power and rpm. Aftermarket heads don't yield much reward for the risk on these engines
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Hopefully Matt will chime in sometime but it's my understanding that you will need to run higher octane gas with that head. Might contribute to the initial not starting issue.

That head was designed for racing and will probably increase the amount of maintenance and decrease the reliability of the motor.

On the bright side. That's a very cool and very rare part at this point in time. Matt sells his aftermarket heads for around $125
 
I took the head off and one cylinder the piston and that side of the head is all rough while the other side is all smooth. Don't know how that happened but I think I'd be better off with a new engine at this point. So I'm going to probably go steal another motor from another jet ski and see if it works.
 
Well, at least we have gotten to the source of the issue. I am sorry to hear that it wasn't some better news.

I wish you the best of luck on the hunt for a used motor. You need to be very cautious about this process and make sure your not spending money on a motor that is going to have problems of its own.

I still highly recommend looking into one of the sites that sell motors and offers a warranty. You may be spending more money, but there is a lot to consider. A motor you know beyond a doubt will work, the peace of mind provided by the warranty, and with that peace of mind the fact that even if something goes wrong you just get a new motor for free.

Sites like Seadoo Engine Shop and SBT sell a lot of motors to jet ski rental companies. that alone is a sign that says these motors are ready to run and be banged on for a long time.
 
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