Engine will not Run

[JustCruzin]

I've had my 1996 Seadoo GTI for about 10 years and basically had no problems other than batteries, a couple of exhaust issues, replaced motor mounts, and rebuilt jet. So I'm out on the river and rode for a while and then stop intentionally. But then I have hard time restarting the watercraft. Hard starts continue with somewhat rough idle. Also had a couple of occassions where I would be going fast, do a spin, and reapply full throttle with engine running but boat hardly moving and then suddenly everthing would reengage and I'd accelerate again normally. So on the last day the boat was run everything seemed normal and then it died after a spin. After that I could not get it restarted.

So I started researching things. I was getting spark to both plugs. Put in new plugs. Everyone was talking about clogged carb fuel filters and the need to replace the Tempo lines. I replaced all the fuel lines, connectors, fittings, fuel selector valve, and fuel filter. Fuel tank was drained and cleaned. Duel Mikuni carbs were completely rebuilt at considerable effort. The carbs did not look that bad, except perhaps the carb fuel filters. The Mag filter was dirty, but the PTO rear carb filter looked clogged so I had reason to believe this might be the root cause. I also had some goo that came out of the fuel selector valve and the inlet/outlet ports on the carbs looked a little gunky. I took the oil pump off and converted to an oil blocker plate. Everything is completely reassembled and now is doing basically the same exact thing. Cranking, cranking, cranking. Battery good, starter good. Spurt starts and dies occasionally. Adjusting carbs I was able to get it to idle once without dying, but as soon as I apply gas dies again. Now it wont start again. Any ideas where to go from here. I was hoping to hit the water again before the season is over, but it is not looking good.

 

[bigJake]

I've had my 1996 Seadoo GTI for about 10 years and basically had no problems other than batteries, a couple of exhaust issues, replaced motor mounts, and rebuilt jet. So I'm out on the river and rode for a while and then stop intentionally. But then I have hard time restarting the watercraft. Hard starts continue with somewhat rough idle. Also had a couple of occassions where I would be going fast, do a spin, and reapply full throttle with engine running but boat hardly moving and then suddenly everthing would reengage and I'd accelerate again normally. So on the last day the boat was run everything seemed normal and then it died after a spin. After that I could not get it restarted.

So I started researching things. I was getting spark to both plugs. Put in new plugs. Everyone was talking about clogged carb fuel filters and the need to replace the Tempo lines. I replaced all the fuel lines, connectors, fittings, fuel selector valve, and fuel filter. Fuel tank was drained and cleaned. Duel Mikuni carbs were completely rebuilt at considerable effort. The carbs did not look that bad, except perhaps the carb fuel filters. The Mag filter was dirty, but the PTO rear carb filter looked clogged so I had reason to believe this might be the root cause. I also had some goo that came out of the fuel selector valve and the inlet/outlet ports on the carbs looked a little gunky. I took the oil pump off and converted to an oil blocker plate. Everything is completely reassembled and now is doing basically the same exact thing. Cranking, cranking, cranking. Battery good, starter good. Spurt starts and dies occasionally. Adjusting carbs I was able to get it to idle once without dying, but as soon as I apply gas dies again. Now it wont start again. Any ideas where to go from here. I was hoping to hit the water again before the season is over, but it is not looking good.

were the carbs rebuild with OEM kits or aftermarket kits? aftermarket kits will leak and flood the cylinders making it hard to restart.

 

[El Toro 33809]

Is the rotary valve gear damaged and the plate timed correctly?

 

[JustCruzin]

I used OEM Kits.

 

[JustCruzin]

When I took the oil pump off, there was a gear that drove the gear on the oil pump. That gear looked fine. I do not know how to do timing. I called a repair place in town that is booked for 3 weeks. They said the next thing to do might be to check cylinder compression.

 

[jhjesse]

Replace the new needle and seat springs with the old ones. Chances are good the the new springs are too stiff to let the needle open.

The fuel filter/water seperator O ring needs to be checked. Use some vaseline to reinstall. This will insure a good seal.

Selector valve new? If not, just replace it. They have a rubber grommet inside and between the green goo and cleaning solution it becomes damaged.

Pull the plugs after trying to crank and see if they are wet.

 

[manolocross]

When you rebuilt the carbs did you replace the needle and seat???If these are no good they will leak fuel into engine causing hard restarts and rough idle cause too much fuel is flowing...

 

[JustCruzin]

The fuel selector valve is new and the fuel filter assembly is new. I did not install grease on the O-ring in the filter assembly but I did siphon the gas to the carbs in the new fuel lines before making the final connection and the gas came immediately up. I did have some issues with setting the popoff pressures. I had to test with the back off and the round diaphragm removed to see and hear when the needle popped off. When I used a small hand held pump, I could not build popoff pressure above about 15-20 psi with the carbs assembled. But when disassembled and connected to a compressor, I got fairly consistent popoff pressure around 40 psi with the stiffer springs in the rebuild kit. I'll check the plugs for a wet condition after cranking. Thanks for your help.

 

[JustCruzin]

Yes, I did replace the needle and seat with a new 1.2 set which is what I thought I saw recommended on one internet site.

 

[BanOne]

If you can't build enough pressure when the carbs are together I think that indicates that the level for the needle may not be adjusted correctly, since it works when you dis-assembly the coves that might be something to check.

 

[Bills86e]

If Water gets into the motor, either by flipping the ski, buying in gas from seller, permiation into tank ect, it does major damage to the Rotary
Valve cover, and eats at it. Then with the clearance opened up it breathes from the adjacent hole. As the clearance gets worse so does the
performance of the engine manifold pressure resulting in hard starting and an early grave for the starter motor. SBT has an exchange for about $100, if you can check the RV cover tolerance useing the Shop Manual proceedure. Your ski is 15 years old so while you have the cover off, test your oil pump flow rate with your drill.

I had a buddy ask me to help figure why his 18 year old ski seized, his spark plug wires were badly burned in the pto plug boot, My guess is then it overheated, passed hot compresson by the rings until it detonated and melted the piston top. Unscrewing the *plug boots and cutting
a 1/4" is something to do annually, zip-tie after re-screwing the boot back on.

Bills86e

 

[JustCruzin]

Ok, today I have a little more information. I pulled the plugs. Both were wet. Then I went and bought a cylinder compression test kit and proceeded to test the cylinders. The Mag cyclinder was reading 130 psi and the PTO cylinder was 135. Funny thing, I reinstalled the plugs and was able to start the engine but could only get the boat running in rough idle. Any applied throttle and the engine immediately died. Repeated and started again but in rough idle. Applied throttle and died again.

 

[Bills86e]

Pop-off should be about 48 psi, with N/S 1.2, LOW- 1-1/4, HIGH- 0, re-use stock springs.

 

[JustCruzin]

Well, I just got news from the repair shop where I sent the boat for a diagnostic. They tell me they removed the rotary valve cover and observed that the rotary valve was not turning when the starter was actuated. They said that the compression on the heads was good but that it needed a new rebuilt motor which they would install for $3000. I asked if it could just be a stripped helical gear on the rotary shaft assembly and if that could be replaced. They said it would be the same price to repair and replace. So after a diagnostic charge of $185 and two weeks later, it looks like I'm going to get the boat back in an inoperative state.

Does anybody have recommedations? Can an inexperienced guy like me successfully replace a rotary shaft assembly? What are the odds that I can do this? I see a place where I could buy a shaft assembly for about $90 and a timing wheel for $14. How long would this take and would I need to remove the motor to do the repair? I have a new fuel system, rebuilt carbs, cleaned gas tank, new grips, good battery and starter. Cylinder compression is 130 psi for Mag and 135 for PTO. Should I cut my losses on this Seadoo and forget about it? Could it be that the rotary shaft assembly is not the problem but something more serious?

 

[Bills86e]

YES, you can do it yourself if you have space, time and can download a shop manual, and have a set of tools, metric sockets and Beer! :thumbsup: Read the shop manual cover to cover, get your ski back, DIY = save $$$$$$

 

[Superneil018]

yes, you do have to remove the motor to do the repair.

 

[El Toro 33809]

If the brass gear is damaged you will need to split the cases. First of all shavings will be in the cases which need to be flushed out. When the are split you will need to check the location of the gear on the crank shaft. It may have shifted off center and that issue would need to be addressed. Good luck!