Hello,
I recently picked up a 1996 seadoo XP 787 that was rebuild by some guy in his garage. I took it out and ran it no more than 15 secs and the engine ended up seizing when I tried to crank the starting motor. I ended up pulling the engine and getting it unseized, tested compression and put it all back together.
I initially though it was a lack of oil that caused the seizure since the plugs were really clean, there was very little smoke coming out of the exhaust for the time I ran, and the guy who rebuild it said he did not know much about jet skis (forgetting to bleed oil pump...).
Took it out on the water today for about 10 minutes and ran decent. I stopped it for about 3 minutes and then it cranked over and seized again. I ended up pulling the engine again to get to the bottom of the seizing because now i know it’s not oil (i’m running 50:1 premix and i know the oil pump is working and oil is getting into the cylinders).
Ended up taking it apart and was confused at first because the cylinders looked clean and in good shape, everything was oiled up as it should be, crank felt pretty fine and in good shape, and I know it wasn’t overheating since I know I had proper water flow. That’s when I looked at the piston and realized the guy used pistons made for 717cc seadoo.
My thought is that the big issue is that the 717cc engine had no rave valves where the 787 in my XP does which from what I read means the pistons are slightly different. I honestly think the seizure is due to the 717 pistons being used in a 787 engine (both are 82mm bore but i believe they are slightly different).
Let me know what you guys think and if this would be a valid explanation for my seizing. I just want to rule out most things before spending $250-$300 on a proper top end rebuild!
Thanks!
I recently picked up a 1996 seadoo XP 787 that was rebuild by some guy in his garage. I took it out and ran it no more than 15 secs and the engine ended up seizing when I tried to crank the starting motor. I ended up pulling the engine and getting it unseized, tested compression and put it all back together.
I initially though it was a lack of oil that caused the seizure since the plugs were really clean, there was very little smoke coming out of the exhaust for the time I ran, and the guy who rebuild it said he did not know much about jet skis (forgetting to bleed oil pump...).
Took it out on the water today for about 10 minutes and ran decent. I stopped it for about 3 minutes and then it cranked over and seized again. I ended up pulling the engine again to get to the bottom of the seizing because now i know it’s not oil (i’m running 50:1 premix and i know the oil pump is working and oil is getting into the cylinders).
Ended up taking it apart and was confused at first because the cylinders looked clean and in good shape, everything was oiled up as it should be, crank felt pretty fine and in good shape, and I know it wasn’t overheating since I know I had proper water flow. That’s when I looked at the piston and realized the guy used pistons made for 717cc seadoo.
My thought is that the big issue is that the 717cc engine had no rave valves where the 787 in my XP does which from what I read means the pistons are slightly different. I honestly think the seizure is due to the 717 pistons being used in a 787 engine (both are 82mm bore but i believe they are slightly different).
Let me know what you guys think and if this would be a valid explanation for my seizing. I just want to rule out most things before spending $250-$300 on a proper top end rebuild!
Thanks!
