SEA DOO 717 FUEL OR ELECTRIC PROBLEM

[JAYSONFLYNN]

1996 GTI with 717 won't idle consistently and is hard to start. Runs great after startup at anything above idle, but when coming back to idle acts like it's loading up, have to feather throttle to keep running. Can pull the choke halfway and it tries to die. Adjusting low mixture screws and its noticeable when gets lean or rich, runs even worse. Premixing at approx 45:1.

Motor has 20 hours after complete rebuild, 140 on both cylinders. SBT machined rotary valve cover and rotary valve. New fuel lines, deleted fuel selector valve and routed to reserve on the pickup. Removed original water separator and added inline filter. Lots of new plugs and now running iridium NGK's.

Thought it was a carb issue, bought another set and had them professionally rebuilt, but no change. It's charging at 13.7 (have an auxiliary gauge mounted).

Check valves are probably original, about the only thing I've not changed, although did loosen fuel cap to see if vapor locking, not change. Removed seat to make sure not taking in exhaust, no change.

Any advice or ideals appreciated.

 

[mikidymac]

Get rid of the inline fuel filter and go back to the stock strainer/water separator.

What is your idle set at? Could it just be set too low?

 

[daredevil95]

Sounds like fuel to me....one of the 3; carb/old fuel lines/selector needs attention although, I have limited experience but, I recently for the most part replaced almost everything on a 717 engine...

 

[JAYSONFLYNN]

Idle is set on the high side to try to keep it running. I will remove the inline filter and let everyone know how that effects it.

 

[Ckrawiec]

From everything you've said....this really sounds like a fuel delivery problem.....the older skis are pretty finicky.....I've been fiddling with my '96 GTX for years to get her tuned in correctly......took many tries with new Mikuni carb parts, adjustments, etc....until I finally think I got her dialed in just right (this season).

Yes, I have also battled "electrical" issues too, but in the final analysis....the fuel delivery system HAS to be spot on (and that includes Idle adjustment screw settings, etc......). The older skis WILL try your patience. Good luck with it!

 

[mikidymac]

If the idle is set too high just to keep it running then you have a problem that needs to be fixed. You can't fake it on these.

 

[JAYSONFLYNN]

CKRAWIEC, yes they absolutely do try your patience. I've fiddled with this ski so much.... but when you open it up on the water it feels worth it. LOL

 

[JAYSONFLYNN]

UPDATE: Family took the ski to the lake today. Much better than before, it does idle now, thanks everyone... Here's what was done.

Removed the aftermarket WIX fuel filter and reinstalled the factory filter as mikidymac suggested. Adjusted the low speed screws to 1 1/4 out. Was adjusting by feel and position of the T before, figured out the screws do not seat equally, so that method leaves the carbs with different low speed settings.

The low speed circuit still doesn't feel crisp throttle response and to start have to give it just a bit of throttle. Sometimes it will start immediately and then immediately die, then again giving it just a bit of throttle and it starts after about 15-20 sec, but does come back to idle after a full speed run.

Thoughts on this guys?

 

[POPPS]

I would clean the carbs and get that out of the equation.

 

[JAYSONFLYNN]

Catching up... Cavitation was an issue with tuning. After figuring out the kids stripped the driveshaft and blew the neoprene seal, replaced it all and made the alignment tool with this forum (works great!).

Still not starting like it should. Have to give it a bit of throttle to start and after 10 seconds of feathering it starts. Runs great at 1/4 throttle and above. Idles great, but seems to load up, have to feather throttle after idling to get it to accept fuel. Yes, I've adjusted 1/8 turn each way on the low speed.

Could this be leaky crankshaft seal issue?

 

[daredevil95]

Catching up... Cavitation was an issue with tuning. After figuring out the kids stripped the driveshaft and blew the neoprene seal, replaced it all and made the alignment tool with this forum (works great!).

Still not starting like it should. Have to give it a bit of throttle to start and after 10 seconds of feathering it starts. Runs great at 1/4 throttle and above. Idles great, but seems to load up, have to feather throttle after idling to get it to accept fuel. Yes, I've adjusted 1/8 turn each way on the low speed.

Could this be leaky crankshaft seal issue?

I was setting my new carb and I noticed that the high speed screw has some effect on idle, it's on the opposite side of the low speed screw...theres a plastic adjustable cap on it that can be removed. My 717 was supposed to be set at zero but, I put it at a 1/4 turn and it runs perfect now. Also, the accelerator pump can be finicky....the adjustment screw on my old carb was adjusted about a 1/8 inch gap under the screw but, my new carb would NOT idle/start easily at that setting, I had to turn the screw out to tighten the gap to almost no gap and it starts on the first shot now and idles great. So, thats definitely any area to look at. Good luck

 

[POPPS]

Thats super odd that opening the hi-speed helped the idle...the hi speed jet does not work below 1/3 idle.

 

[JAYSONFLYNN]

POPPS, the carbs were professionally redone, actually a completely different set of carbs than the ones suspected of issues, but no change.

Leaky crankshaft seal cause this hard to start issue or possibly something electrical?

 

[POPPS]

The 720's are known for leaky crank seals,,,but that effect is upon inital startup,,,very smokey,,,and sometimes oil hydrolocked...just wondering,,,does the new carb have all new mikuni parts,,,I have an 800,,,I went thru the carbs,,(leaking fuel,,,very dangerous!!!,,,due to an AM gasket),,,and needs throttle to start,,,and should NOT...BUT one of the round diaphrams is AM...very thick and rubbery,,,the customer used them...once you have that ski started and running,,,it should start before you can say "dime!"
...

 

[JAYSONFLYNN]

After a lot of changes, including another set of dual carbs with multiple tuning attempts, lots of spark plugs and about everything else you can imagine with the fuel system...

Turns out the voltage regulator went bad. After riding yesterday noticed the voltage spiked to 16.8 for a moment and then went back down to 13.8 riding (have a auxiliary gauge installed). Also installed a new battery during all this, guess it cooked the other.

Starts immediately now, havn't had it on water yet, although it's not started this good in a long time.

 

[Lothsahn]

Those voltage regulators can be pesky. Basically, they run too hot and burn themselves out. Usually happens at high RPM... Guess yours was different.

Glad you found it and didn't convert to single carb!

 

[JAYSONFLYNN]

Is anyone aware of an upgrade? This is the second one I've put on in 25 hours ride time.

 

[Lothsahn]

When I looked I couldn't find any upgrade, no. It's a shame--I would have paid more for a part that wouldn't fail.

I've had this installed for over a year. So far so good.
https://www.amazon.com/Voltage-Regu...RPN1NFQ#aw-udpv3-customer-reviews_feature_div