97 SPX not starting in the water

[IDoSeaDoo]

I've had this issue for quite some time now. Put in a new engine (used and questionable), it starts and runs on trailer, but smokes quite a bit. But if I put it in water, it doesn't start. If you crank it for a long time, and choke it, it will eventually act as if it's going to start, but never really does.

In troubleshooting, I've done the following to no avail:


-verified correct rotary valve timing
-verified correct rotary valve clearance
-replaced gray fuel lines
-rebuilt the carbs using original springs
-bypassed the fuel selector
-tried running with just a hose in a can of fresh gas
-tried unplugging the rectifier
-verified compression (145 on both)
-verified spark (like the 4th of July)
-checked for metal filings on the pick up coil (none, but there is some paint on the stator magnets, not much)

When I pulled apart the exhaust, it seemed wet inside the pipe, as if it was getting too much gas. On trailer, it runs rough, and upon revving, takes a bit to wind up.

Has anyone out there ever had a sheared flywheel key? How about bad stators? I'm pretty sure this is a timing issue now... I heard it could also be bad crank seals... is there a way to check this for sure?

 

[Bills86e]

Natually Asperated Seadoo 787's

Only thing we are not reading is after assembly of carburetors, the leak-down test,
and synconizing the butterfly's and the final adjustment proceedures, being adhered to. Go to Snipes corner, look at his Plug Chop color chart, and General directions
on final tuneing. Bill

http://www.seadooforum.com/showthread.php?t=4151

 

[IDoSeaDoo]

Blown Crank Seals

Sealed up the exhaust at the cylinder jugs, sealed up the intake at the rotary valve and sloly applied pressure to the pulse nipple. After 3 lbs, I heard bubbling inside the block. Either the crank seals or the block mating surface is leaking Anyone know a cheaper place than SBT to get remanned cranks? Does anyone out there reman cranks themselves? I have two crankshafts, one having a bad rod, but both rebuildable. How much?

 

[bmmeadors]

How can bad crank seals cause the ski to not run in the water?

 

[IDoSeaDoo]

My guess...

My guess is that it sucks a bunch of oil into the crank case, and literally chokes itself. I think that maybe due to the physical construct, it can't fill up all the way and gets just enough air to sustain itself out of water, but as you add the extra bit of drag it can't turn over fast enough to start. This is just my guess, I would love for someone more knowledgeable to tell me.

 

[IDoSeaDoo]

I know I haven't posted here in a while, but I feel the need to wrap up my threads, as courtesy to those looking for answers. I never did get that engine to work right. In the interest of time, I bought another used one, this time guaranteed to run from a person on eBay. Put this engine in (had perfect 150 compression), and had the same problem of not starting in the water. I brought the ski back to the shop, and found that only one of the plugs was firing. The plugs were new, but somehow one of them became fatally fouled. I found this by putting an inductive timing light on them, to find that one was firing away, while the other wasn't. Before, I would just pull the plug cable and put it onto another spark plug (my test plug, which fired fine). This deceived me of the real problem for a long time. Replacing plugs fixed my problem and now I'm chasing other, less debilitating ones, but at least the ski runs If you're having starting/running issues, put an inductive timing light on the plug wires and see how frequently you're firing your plugs. If not at all, check the grounds on the coil and make sure it's getting power. Check fuses, if that's all good, it may be your MPEM or DESS. Good luck to all!

 

[Bills86e]

My guess is that it sucks a bunch of oil into the crank case, and literally chokes itself. I think that maybe due to the physical construct, it can't fill up all the way and gets just enough air to sustain itself out of water, but as you add the extra bit of drag it can't turn over fast enough to start. This is just my guess, I would love for someone more knowledgeable to tell me.

Yes do a pressure test, its one of the most important test you can do. It's not an expensive tool,but its wort it's weight in gold. A lot of people assume that just putting new piston and rings in there engine is the cure all, not always true. A pressure test will show you possible air leaks you never would have expected. On the other hand it can also confirm a nice tight engine. On anther point, if you don't have a tight engine to start with you will never be able to properly tune your ski. Good luck and have fun!