Seadoo Tuner
Member
Background - My 1996 SPI has given me 7 years of mostly trouble free riding after I bought and fixed it after the previous owner had sunk it 3 times and left it out in the elements during winter. Ran at 46mph (on gps) with an intake grate and manual trim on the 587 motor. Stock is usually listed as 42mph so I was happy with the performance. Put just about 100 hours on it over the years. Build thread for it is here :
Anyways, was getting my 96 SPI ready for this summers riding and addressing a bogging issue I had at the last ride of the year last summer (last summer when I was riding to the dock from across the lake and after running fine, power slowly decreased no matter how much throttle I gave it). So this year I removed the carb, disassembled, and cleaned it all (carb was rebuilt a year and a half back with genuine mikuni kit). Increased the popoff from 24psi to 26psi and the small transition ports seemed clogged when I cleaned them out. Took it to the lake and started it and it drove like a dream. Drove for about 10-15 minutes and just before I was going to take it out of the lake I did one short high speed run near the dock and it pulled hard and fine. When I slowed down and was going to the dock I heard a whining noise that seemed to resonate to the front of the doo. After about 5-10 seconds it slowed down and stalled. Wouldn't even turn over at first when trying to restart (battery is only one year old). After waiting a couple of minutes and then attempting restart it turned over very slowly. Engine was quite hot, more than usual as I couldn't keep my hand on the side like I usually can. Made it to the dock and went home. Checked compression at home and mag piston was 130psi, then check PTO piston and had disappointment when it came up at 70psi. Checked again the next day with some fogging oil sprayed in each piston and got 148psi and 90psi, so PTO piston has an issue. Taking the head cover bolts off, 12 of 13 broke, and it seems like the cap screws for the head cover are threaded into the cover (unlike the 720 motor I think) and it still can't be removed as part of the bolt is threaded into it. Will have to drill out the broken off bolts as I tried easy out kit, heat, wax, penetrant and nothing is working.
Any input as to what may have happened is appreciated, I'm guessing a ring broke maybe? Worse case scenario is the crank seals gave out and it ran lean, but need to get covers off and see the piston top first.
Anyways, was getting my 96 SPI ready for this summers riding and addressing a bogging issue I had at the last ride of the year last summer (last summer when I was riding to the dock from across the lake and after running fine, power slowly decreased no matter how much throttle I gave it). So this year I removed the carb, disassembled, and cleaned it all (carb was rebuilt a year and a half back with genuine mikuni kit). Increased the popoff from 24psi to 26psi and the small transition ports seemed clogged when I cleaned them out. Took it to the lake and started it and it drove like a dream. Drove for about 10-15 minutes and just before I was going to take it out of the lake I did one short high speed run near the dock and it pulled hard and fine. When I slowed down and was going to the dock I heard a whining noise that seemed to resonate to the front of the doo. After about 5-10 seconds it slowed down and stalled. Wouldn't even turn over at first when trying to restart (battery is only one year old). After waiting a couple of minutes and then attempting restart it turned over very slowly. Engine was quite hot, more than usual as I couldn't keep my hand on the side like I usually can. Made it to the dock and went home. Checked compression at home and mag piston was 130psi, then check PTO piston and had disappointment when it came up at 70psi. Checked again the next day with some fogging oil sprayed in each piston and got 148psi and 90psi, so PTO piston has an issue. Taking the head cover bolts off, 12 of 13 broke, and it seems like the cap screws for the head cover are threaded into the cover (unlike the 720 motor I think) and it still can't be removed as part of the bolt is threaded into it. Will have to drill out the broken off bolts as I tried easy out kit, heat, wax, penetrant and nothing is working.
Any input as to what may have happened is appreciated, I'm guessing a ring broke maybe? Worse case scenario is the crank seals gave out and it ran lean, but need to get covers off and see the piston top first.
