Seadoo 717 Issue

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john15seadoo

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The original issue I had with my ski was that it would only go about 20 mph at full throttle and at random points it will take off to about 45-50 mph, then after approximately 20-30 seconds, it'll drop back down to 20 mph.

I decided to replace the grey fuel lines, the fuel selector and the carb was rebuilt with genuine Mikuni parts.

The ski started briefly (approximately 2-3 seconds) by putting mix directly into the carb. After that, I have not been able to get it to start - I have tried using a combination of mix, the choke & throttle. Both plugs are getting spark. Compression is at 125 and 127.
 
Well OK then....replacing the old grey fuel lines was a MUST anyway, fuel selector too.

QUESTION.....did you USE the spring in the carb kit? Might be the issue... your ski uses a 115gram spring and the kits don't necessarily have the right springs.....this is IMPORTANT, you can purchase the correct spring individually. Also, did you follow the CARB rebuild Sticky post (top the forum page) and test the pop off pressure, etc.....if not...DO IT AGAIN and get the KNOWN correct spring.

AND finally....your compression numbers look LOW....but don't quote me on that.....I'm not absolutely sure what the compression on a '99 GTI is supposed to be (my '96 is near 145 psi (both) which I understand is good).
 
john15seadoo said:
Yes, the spring in the carb kit was used, it looked identical to the one that came out, and the pop off pressure was also tested.
Click to expand...
If you are certain that you have the correct carb spring, the rebuild was spot on, your pop-off pressure is within range THEN it could be LOW compression......120's is too LOW (I'm pretty sure).....might start and run OKish on the trailer BUT in the water???? Might not have enough umffff to get up and go.... I'd re-test those compression numbers with another guage...borrow one from AutoZone, just to be sure.
 
Yes, the spring in the carb kit was used, it looked identical to the one that came out, and the pop off pressure was also tested. However it seemed low, (approximately 20-22 psi), when I read that it should be around 36-40 psi. Also I’m not sure if it pertains to this issue, but the low speed is set to 1, the high speed is set to 0. I found these adjustment numbers on SeaDoo Source. While the ski cranks, would a combination of these factors prevent it from starting?
 
If your gauge is good and accurate then the low compression is the issue.

Where did you get your carb kit?
The 1999 GTI uses a 2.0 needle and seat and a 95 gram spring which does not come in the Mikuni carb kits.
 
mikidymac said:
If your gauge is good and accurate then the low compression is the issue.

Where did you get your carb kit?
The 1999 GTI uses a 2.0 needle and seat and a 95 gram spring which does not come in the Mikuni carb kits.
Click to expand...
MIKI-> Not being a nudge or ANYTHING....BUT where did you get your spring strength value from?
According to the 1999 Seadoo shop manual:
1999 GTI says = 115 gram spring (not 95 gram).
1999 SPX, GTX Limited, XP Limited, GSX Limited = 95 Gram spring.
1999 GS, GTS = 130 Gram.

So these damn spring strengths are all over the place.....details, details, details.
 
Seadoo is the most confusing of all the manufacturers and you are correct that they are all over the place and even have different part numbers for the same springs.

Only thing I have to go by is from what I have seen and a few of the old pros. Supposedly all twin carb 787 without accelerator pumps use the 80 gram springs. All others use the 95 gram. The 951/947 uses a completely different 95 gram that is specific to them.

Looks like the GTI could be the 115 for 1 to 2 years.

As far as I know there is no such thing as a Mikuni 130 gram spring.

This is why it is best to use the old springs as long as you know they are original.

044= the old '88 '89 '90 bn 38's aka "round bodies", the carbs we had before the sbn series of carbs were made. All of those models had a very short lightweight silver spring that probably was about a 35 gram spring, if that much. The pop off for those carbs is 11.5 to 12.5 psi.

130= 95 gr. Most sea doo's have the 95 gram spring, but not all of them.

313= 95 gr. Special 95 gr. Spring used in all 947 46i carbs except the 1998 gsxl with the white motor.

428 and 374 = 115 gr. Only used in very few sea doo's. One was the white 947 carbs, and another was a model with a 717 engine and a single "i" series accelerator pump carb on it. I think it was a gti for 1 or 2 year models.

242= 80 gr. Actually that is 242 d these came in a lot of 787 engines, probably the most 787's, except the 1997 XP.

264= 80 gr. " " " 264 d I have no idea which carbs these came in, but they too are 80 gr. springs.
 
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mikidymac said:
Seadoo is the most confusing of all the manufacturers and you are correct that they are all over the place and even have different part numbers for the same springs.

Only thing I have to go by is from what I have seen and a few of the old pros. Supposedly all twin carb 787 without accelerator pumps use the 80 gram springs. All others use the 95 gram. The 951/947 uses a completely different 95 gram that is specific to them.

Looks like the GTI could be the 115 for 1 to 2 years.

As far as I know there is no such thing as a Mikuni 130 gram spring.

This is why it is best to use the old springs as long as you know they are original.

044= the old '88 '89 '90 bn 38's aka "round bodies", the carbs we had before the sbn series of carbs were made. All of those models had a very short lightweight silver spring that probably was about a 35 gram spring, if that much. The pop off for those carbs is 11.5 to 12.5 psi.

130= 95 gr. Most sea doo's have the 95 gram spring, but not all of them.

313= 95 gr. Special 95 gr. Spring used in all 947 46i carbs except the 1998 gsxl with the white motor.

428 and 374 = 115 gr. Only used in very few sea doo's. One was the white 947 carbs, and another was a model with a 717 engine and a single "i" series accelerator pump carb on it. I think it was a gti for 1 or 2 year models.

242= 80 gr. Actually that is 242 d these came in a lot of 787 engines, probably the most 787's, except the 1997 XP.

264= 80 gr. " " " 264 d I have no idea which carbs these came in, but they too are 80 gr. springs.
Click to expand...
Holy hell batman.....wtf!!!! :nerd:
 
So the same thing happened today, I put new NGK BR8ES spark plugs in and was able to get it started once, but only for approximately 5 seconds until it died. My one friend said that I have inconsistent spark at the plugs. Could this be the issue & how would I go about fixing it? Is it the ignition coil inside the e-box or would it be the magneto. Thanks.
 
Try cutting the zip tie and unscrewing the spark plug caps then cut 1/4" off the wires and screw the caps back on and install a new ziptie. I also suggest pulling all electrical connectors and make sure they are clean and apply some dielectric grease on all the seals.

Do you get 2 beeps when you put the lanyard on?

Did you ever veridy and resolve the low compression?
 
All of the connections appear to be good. The white wire on the ignition coil seemed a little loose - tightened that up, however still will not start.
 
Also does anyone know any specifications on the stator, I have a box of parts I received when I inherited the ski, however I am not sure whether this is an aftermarket or oem product. I am trying to piece together whether its an old or new stator & been replaced or not. The starter solenoid and ignition coil are relatively new, however the box does not seem sealed, perhaps water could've gotten inside?
 

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Okay so within the past 1-2 years the stator, starter solenoid and ignition coil were replaced. The ebox did not seem sealed / completely shut though and water may have gotten inside, but the connections do not appear to be corroded or anything.
 
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