I got my first SeaDoo on Wednesday this week, and (against my better judgement) I bought it private for cheap. It started strong, ran well and sounded alright when I bought it. Thursday, I did some basic maintenance while it was on the trailer. I greased the mid bearing in the rear, put 2 new spark plugs in (NGK from a SeaDoo dealership), put dielectric grease in the spark plug caps, installed a fully charged new battery, and threw a glug of 2-stroke oil in the gas tank just in case the oil injection doesnt work. I hit start and it fired right up, a little white smoke came out but nothing concerning. I let it run for 20 seconds, shut it off, filled the tank with gas and headed to the lake. Once it was in the water, it turned over but wouldnt start. I tried for 15 minutes to start it, holding the start button for 5-10 seconds with 1 minute break in between, but no success. Defeated and pissed, I drove it home and put it in the shed. I took the spark plugs out and they looked wet like it was getting gas (I shouldve took a picture). I grounded them to the block and they sparked when the motor turned over. But now it wont start out of the water either. Can anybody help me figure out why this wont run? My next diagnostic is to check compression.
The second thing is it has a patch on the bottom that I need to redo. What tools do I need for this? Can someone recommend a good fiberglass repair kit and gelcoat repair kit? Or a good guide to follow?
I hate to say this, but you sound like you could have some engine work needed. People get excited when they get a good deal on a motor, start it on land, runs like a brand new one, then put it in water, and it floods out, won't run. If your in the water, and you start it, then shut it down, will it still turn over, or does it only spin a bit, then stop like it has a dead battery? When you pull the plug, does it spit water from the mag cylinder?
This is why it's so important, not to buy a ski, sitting on land. When you have no water in the water jacket, the engine will run fine. When you put it in water, you have several gaskets that must hold up, for the engine to fun. If you have access to a compression gauge, do a compression test to both cylinders. You should get between 90 to 110 psi. It's not so much the pressure, as it is the difference between the two.
If you look at the cylinder head, lets dive in a bit, when you pull off the top bolts, you'll pull off two covers, bot are cooling jackets. When you do that, you'll see the pistons. You'll be looking for standing water in the piston, or signs that water was standing in it. If you see water in the water jacket, then that means those two plugs, at the lowest part of your cylinder, are plugged. Once you have it apart, blow those out and get them working again. They are what keeps the engine from freezing.
Now, here's the most important part of your inspection. Where that first head lays down on top of your poistons, there are 2 tiny "o" rings that fit on those cylinders, at the very top. They are about 1/16 in diameter, and really small. Take a razor or sharp edge, and put it out. If your careful, you won't break them, and possibly, be cause to re use them again. You can get an upper end gasket kit for about $40 bucks, I recommend it. After you clean those 2 rings out, get a tiny about of grease, just enough to make them sit in place. In the process, you'll also be placing those 2 bigger gaskets back on. Once you have those cylinder gaskets on, then your square gaskets that fit each head, put them on. The most important part is next. When that cylinder head is on, there are 2 red "0" rings that you will put on at the place with your spark plugs are screwed in. Don't screw them in yet, but put the red o rings on the head, where the holes are, because they are a tight water seal.
Seadoo has this design set up so that if you run it dry, it'll be good. If you put it in the water, and it runs like crap, then you know, you got the cooling system screwed up. There are also tests you can do;. You can test the cooling system for up to 5 psi, and do a compression tests on your pistons to make sure those rings seated. just because the motor runs good out of the water, DOES NOT MEAN IT WILL RUN GOOD ON THE WATER.
I have an entire instruction set up on doing these tests. I take a laymans term to iit, and it you ereally want to do this, and make sure you get to ride, don't take SHORT CUTS!!!!!