2003 Sea-Doo GTI 717 not starting in water

Bdcarey89

New Member
Hello,

I’m new to this forum, but I’m hoping I can get some answers. I have 2 x 2003 Sea-Doo GTI 717. I have been trying to get them ready for summer, I had the carbs rebuilt, all new fuel lines, new plugs, wires and coils. My issue is, they start completely fine on the trailer, I set the idle out of water for 3000 RPM +/- 100 RPM, the manual told me 3000 but I can’t get them to “hold” 3000. Everything has been done to spec, according to the manual, but they absolutely won’t start in the water. I haven’t checked the rotary valve, but I’m assuming it should be fine since I haven’t ever touched it? I’m not sure where to even start at this point, any advice would be great!

Thanks in advance!
 
Id check the rotary but you could try to raise the idle or give it some throttle. Also did you use genuine mikuni parts for the carb rebuild?
 
My seadoo usually bounces by about a 50/100 rpm, so as long as you are close to that you should be fine. IMO that number is used to get you in the water so you can set the RPM in the water by what the book say, that is the one you want to focus on, when you get it running in the water that is. So to focus on the primary issues. Did you use an OEM carb rebuild kit? Are the other parts OEM, or aftermarket? Which are OEM and which are aftermarket? Have you checked your compression? Why did you get all new parts for each one? Was there an issue you were trying to solve?

Finally, Both are doing the exact same thing?
 
I did OEM parts, except for the spark plug wires and fuel line. i used thicker walled fuel line. The issue was that i had some water at the bottom of the tank last year, i flushed it all out and i just got nervous that it got through the carb, so i was like "i guess its time for maintenance". the 1 seadoo had this problem last year as well, before i did the carb rebuild. the other seadoo will start fine either way now, i just had rpm set to low in water. But the one that i've had issues with i thought maybe the carb rebuild and everything else would help. im going to pull the rotary valve cover this afternoon
 
How much compression do you have
I don’t have an accurate compression tester, I’m a heavy duty mechanic, not small engine, so normally when I go to a job site it’s really obvious lol. I’ll pick one up tomorrow and advise, in the process of machining these surfaces to be 100% true
 
You can rent one at any autoparts store, its a free rental when you bring it back.
Hopefully you found the issue then. If not let us know the latest on what they are doing. Glad you used OEM, I think that probably saved you a lot of headaches. Yeah with spark plugs you just need to make sure you have the right "number" in there. With the wires just make sure you don't have a lot of slack, sometimes that can cause issues.
 
You can rent one at any autoparts store, its a free rental when you bring it back.
Hopefully you found the issue then. If not let us know the latest on what they are doing. Glad you used OEM, I think that probably saved you a lot of headaches. Yeah with spark plugs you just need to make sure you have the right "number" in there. With the wires just make sure you don't have a lot of slack, sometimes that can cause issues.
Yeah, from the little I’ve worked on small engines, seems like if there is to much slack the spark can jump if the Leeds are close. Also, I only use NGK plugs on all my toys, so I’m not sure if that’s the right thing or if they recommend something else?
 
Yeah, from the little I’ve worked on small engines, seems like if there is to much slack the spark can jump if the Leeds are close. Also, I only use NGK plugs on all my toys, so I’m not sure if that’s the right thing or if they recommend something else
NGK are good plugs, that's what I have in my seadoo.
 
The family GTI had low compression and bigger rotary valve clearance than that and it started in the water. I seem to remember it was .019 inch. Sure you had spin it fast and a lot when it was cold out of the water, but it would start. Once it started on the trailer at the dock, it would start in the water. I would be surprised if the rotary valve clearance is your only issue but I have only worked on one ski. No expert here.

I must say compression and correct rotary cover gap makes starting a lot faster.
 
Found my other issue after doing rotary valve. 90 psi on both cylinders. So new top end ordered. Not sure if it’s just a head gasket or rings, so getting gaskets plus pistons
 
Found my other issue after doing rotary valve. 90 psi on both cylinders. So new top end ordered. Not sure if it’s just a head gasket or rings, so getting gaskets plus pistons
WAIT, 90 pounds on each cylinder? Harbour Freight tester? The testers from there are notorious for false low readings.
 
Even if its off I'm sure its not off by 60psi but I agree, Harbour freight is not a good tester

Not sure if snap-on tester is better but that's still very low.
I rechecked with my MAC tools compression tester, it’s showing 130 psi on both, dead even
 
Looking at your picture of the rotary valve cover you have .39mm written close to port, that measurement equates to about .015” if that measurement is your clearance there? It’s not horrible. I think the wear limit is .014 and I’ve heard from a few people of having in excess of .017 and more of clearance and still not having any issues starting on the water. Just saying, if your worst measurement is .015 unless you have some deep grooves I don’t think that’s your problem
 
Id start checking your carbs, everything is different in the water. There's not much more to eliminate and I definitely thing the RV is not you problem
 
Id start checking your carbs, everything is different in the water. There's not much more to eliminate and I definitely thing the RV is not you problem
So, finally got it out, it starts in the water. Now I can’t get more then 5500-6000 RPM. I feel like the carb was possibly tampered with by previous owner. Can anyone tell me where to get an OEM jet kit for the mikuni carb? I want to ensure I have all OEM parts
 
You could look first to see if you have et ne right jets before purchasing new ones, I haven’t looked back at your thread, have you looked at the raves?
 
You could look first to see if you have et ne right jets before purchasing new ones, I haven’t looked back at your thread, have you looked at the raves?
I wasn’t aware that there was rave valves in these machine. I thought the rotary valve was the replacement for the rave valves.
 
I wasn’t aware that there was rave valves in these machine. I thought the rotary valve was the replacement for the rave valves.
There’s not rave valves in it, I looked back and see that it’s a 717. If u have compression and spark, all that’s left is your fuel, probably already been asked but did you rebuild them with genuine Mikuni? I would suggest the back to OEM kit from OSD marine and follow Mikidymac’s carb rebuild thread, maybe pressure test the fuel system first or bypass the selector valve and fuel filter to rule them out, what type of fuel line do you have? Could be sucking air in somewhere as well.
 
There’s not rave valves in it, I looked back and see that it’s a 717. If u have compression and spark, all that’s left is your fuel, probably already been asked but did you rebuild them with genuine Mikuni? I would suggest the back to OEM kit from OSD marine and follow Mikidymac’s carb rebuild thread, maybe pressure test the fuel system first or bypass the selector valve and fuel filter to rule them out, what type of fuel line do you have? Could be sucking air in somewhere as well.
I had dealer do the carbs, so I’m not 100% sure on what kit they used. I will order a mikuni kit with new jets. I just replaced every single fuel like in the ski
 
I had dealer do the carbs, so I’m not 100% sure on what kit they used. I will order a mikuni kit with new jets. I just replaced every single fuel like in the ski
I doubt it was a dealer as they won’t work on these anymore and I have little to no confidence in a mechanic working on these, even marine mechanics who aren’t familiar with them, there experience can almost be a hinderance. If you have spark and compression, the only thing left is fuel, I would order the back to OEM kit from OSD, it will come with new needle and seat and I would just order the new lever and pin in case someone was bending it trying to set pop off, which your not supposed to do. I would just have a look and see what’s written on the jets as they are probably the right ones. It’s written on them, but you will probably need a magnifying glass, I can sometimes make out the main jet markings by taking a picture and then expanding the picture, but not with the small one.
 
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