2000 Genesis 1200 (carb) electrical issue

[Seth.parks014]

I had my skis out this weekend and had some issues with the genesis. It started and ran fine for about 5 minutes and then died while I was riding at open throttle. The multifunction display went completely out as well. I towed it back with my other ski. I got it home and disconnected the battery and reconnected it. All electronics came back on. Being OCD, I checked the skis voltages. 12v at battery, starter solenoid and start button. The only thing that I found that concerned me was a bad connection from the ground wire coming from the multifunction display and start/stop wiring. I addressed the issue and got a good connection. All ground wires ohmed to the engine like they should after that.
I got the ski out again yesterday and same thing. I didn't lose the electronics. It just stopped running. I tried to restart it but the ski acted like it had a low battery. MFD showed 11.2 volts at resting and under 7v when I would try to restart it. I towed it in again and put a new battery in it. I took it back out to test it and it did the same thing. This time I could immediately restart with extra throttle. I could get the ski running at a lower RPM. It didn't stay at 1350 where it was set at. It dropped to 900-1000 RPM at idle. I took it home and started testing everything.
Battery voltage showed 12.4v on the battery. MFD shows voltage as 11.7-11.8v. With throttle, voltage on MFD went to 12.3v - 12.7v.
I did a quick check of all of the wires to rule out the possibility of a loose wire. Everything checked out good that I could tell.

Every ground ohmed to the motor.
Red/purple wires show 12.4v.
Start/stop button ohmed like it should.
Lanyard button ohms like it should.
Bilge and reverse gate works with motor off.

My immediate concern is the MFD only showing 11.7 volts.
Where else do I need to look?

[Seth.parks014]

I had the ability to fine tune my search today. I ohmed the black ground wires in the ebox. All grounds showed .000 on my multimeter but the black wire coming from start/stop and lanyard assembly each showed .800 ohms. I exposed all of the wires going from the ebox to the MFD. There’s a connection where 4 ground wires connect into each other. The spot looks slightly corroded. I rewired that connection and sealed. Multimeter shows .000 ohms now.
Still looking for other issues.

[Myself]

Compression test......sounds like it was lean seizing on you.

[Seth.parks014]

Compression test mag-125 middle-125 pto-0
I believe the ground wire corrosion was the electrical fix, but now I get to rebuild the top end! The pto cylinder looks like it didn’t have an oil going to it. All of the oil lines are intact and connected. I probably need to test the oil pump too.

[Viper Pilot]

Just had an oil pump seize on me. Check your lines, but if they're original use this as an excuse to replace all of them.

[Seth.parks014]

I believe that they are the originals and I’ll definitely change them out this off season. What would cause the lean seizure in one cylinder vs the other two or all of them at the same time? I know those oil pumps are reliable.

[Myself]

A lot of times it's simply a crapped up carb. It could also be a leaky rear crank seal.

[Seth.parks014]

I ended up finding a used cylinder and piston on eBay. Cross-hatching is still on the cylinder and only super small scoring was found on the piston. Clearances/tolerances are within spec and honestly…everything looks better than my other 2 cylinders. Should I replace the used piston with a new one plus rings or will it be fine with the used piston?

[Myself]

The used one will be just fine. If good used parts are still in spec then it's a GO!!

[savageman69]

Just had an oil pump seize on me. Check your lines, but if they're original use this as an excuse to replace all of them.

how does the oil pump seize exactly when it runs off the flywheel bolt...ive had over 18 polaris and worked on many more never seen an oil issue

[Viper Pilot]

You guess is as good as mine. I can put the pump in a vice, put a crescent wrench on the drive tab, and it won't turn. It's frozen solid. Perhaps it was the fact that it sat for a year and a half, but one would think something caused by lack of use would show us as soon as you tried to use it, but I tested the pump for rotation before I installed it on the new engine and it rotated smoothly and easily. After a few times running the engine for 10 seconds at a time to test everything, it failed.

Edit: After re-reading the post, I think some context should be added. The pump seized and cause the flywheel nut to spin off and the flywheel to pop off the crank. I can see the confusion if you didn't have that piece of information that I detailed in another thread. It's not like it seized and there were no other consequences.

[Seth.parks014]

Alrighty, I got a good 75 degree day to work on the ski. The used cylinder and piston are doing good so far! 122 PSI after testing. Now to find out WHY it seized.

[Seth.parks014]

I’ve got the PTO cylinder rebuilt and everything is put back together. I do have a question though…. I’ve been thinking of causes of the seizure.

Is the seizure the PTO cylinder experienced from towing the ski? I never clamped the hoses when I towed it. The original issue seemed to be electrical since the ski would shut off with no warning. Could water have gotten into the motor causing the cylinder to run lean or displace the needed oil?

[Seth.parks014]

I finally got around to pulling the motor. The drive coupler for the oil pump has deteriorated. At least I found the original problem. I’ll bench test the oil pump and my carbs are being rebuilt but JetSki Solutions. That should eliminate any problem for the oiling system.
I already got the motor out so I’m changing the crank seals and doing a complete top end rebuild.

Is it just one crank seal in the front p/n(3610044) and the double seal in the rear p/n (5411937)?