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**Bryan Glynn** · 07-31-2002, 04:47 PM

I think you seized it, either due to bad gas, water in the fuel, or a clogged carb. Letting it sit for a year then running it without the proper maint. is asking for trouble.

I would at the very least rebuild the carb, and completely clean out the fuel system.

**pmc8888** · 07-31-2002, 05:44 PM

I don't know about "seized", but I do agree about the fuel. I came to that determination today. I've drained tank, drained lines and am going for fresh gas now. You're right about the maintenance, should have done better. I'm hoping that this freah fuel will get it running.
Thanks for the reply !!

**Bryan Glynn** · 07-31-2002, 05:50 PM

99% of the time, 'just quit' means seized. It quickly cools down and rotates after that, but it seized for one reason or another. The exception is when it's an electrical.

**pmc8888** · 07-31-2002, 06:10 PM

No, didn't "seize". As I originally posted, tried to start it after it quite (right away), and it just cranked like no spark or really flooded. Actually, I think I got some bad gas on the way to the launching ramp. It makes sense now......it ram 5-8 minutes (maybe less) and then quit. Just enough time to use the gas in the the lines, filter, pump and carb prior to ingesting the new fuel (assumed bad) that I added after running it on land, but prior to running in the water. Makes sense, but it never "seized".

**Bryan Glynn** · 07-31-2002, 06:40 PM

OK.

**pmc8888** · 08-01-2002, 09:24 AM

Drained fuel tank, line and pump. New diaphram in carb (couldn't get rebuild kit locally).

Still will not start. After cranking over, I removed plugs (slightly wet). Dried plugs, cranked engine (w/o plugs installed and seemed like quite a bit of fuel vapor was expelled), reinstalled plugs. Cranked engine over, it will run for about 2 seconds then quit. This can be done over and over.....same results.

Also, w/o the air filter and attachments installed, if engine is cranked with WOT, fuel vapor is expelled from top of carb. Is this normal, or does this indicate rotory valve problems? What about setting the fuel needle and seat level (that is opened by diaphram)? Could this be set wrong? How is this correctly set up?

Thanks

**Bill O'Neal** · 08-01-2002, 09:33 AM

The wire loom that connects the coil and the CDI (inside the mag housing) can cause a problem like this.

When you re-installed the RV cover, did you use the fat oring or the thin oring on the outer diameter of the RV cover? A fat one will cause this type of problem.

Did you do a pop-off test on the carbs to make sure the needles are seating and not leaking ?

I'm hoping your compression gauge is just reading low, as 155 psi is the standard for compression on that model motor if it is oem.

**pmc8888** · 08-01-2002, 09:47 AM

Haven't taken the engine apart other than down to pulling the carb to clean and install diaphram.

Don't know about pop-off pressure test and settings.......explain. Although a certified mechanic, I have never worked on these engines so am "green" regarding this issue.

If I had to guess, it seems like the engine is flooded with fuel (and possibly oil). When plugs are dry and engine is spun over w/o plugs to "clear" cylinders of excess fuel/vapor, it will fire and idle for a couple seconds.

Compression may be closer to 150 but not above that. The last few times it was run (a year ago), a little 2 cycle oil (tcw3 outboard oil) was added to fuel tank at the rate of no less than 50:1 or so as an additional lubricant since it sat for quite a while and I wanted to run it so as to make sure no lubrication problems. Opinion on this?

**Bryan Glynn** · 08-01-2002, 09:56 AM

See our article here.

**pmc8888** · 08-01-2002, 10:10 AM

OK, read the article.....thanks very much. Now, explain the two fuel lines at the carb. It appears to me that one line is a fuel supply from pump, and one is a fuel return to the tank for excess fuel when N&S are closed. Is this correct? If not, could I have reversed these lines when reinstalling carb?

The carb (single carb) that is on this engine has a round diaphram cover with six screws and 2 locating pins. My local dealer didn't have a kit for this carb. He had only the kit for a carb with a square type cover.

The N&S looked good with no scratches or grooves in it (dealer agreed). I've tried spraying fuel into carb as I'm cranking it with no change in start-up success.

When the ski was brought back from ramp originally.....plugs were removed and it was really flooded. Can fuel collect or "puddle" inside the engine (crankcase area)?

SP · 08-02-2002, 09:11 AM

You need the rebuild kit for the Mikuni BN 38mm carb. I would also buy a needle and seat because it sounds like yours leaks.

You will need to grind down a 10mm socket to make it skinny enough to remove the seat.

You should also perform a needle leak down test if you want to test the needle for leakage instead of just replacing it.

You may want to pressure test your motor itself. Does it smoke alot on start-up? The crankshaft inner seals may be allowing oil to seep in to the motor, or you may have an air leak from the PTO or Flywheel seal.

**Michael73** · 08-02-2002, 09:29 AM

This may sound silly but I figure if everyone chips in, it can only help.

My kawa 550 was having that problem after I sank it doing a rooster tail, it would start for about 2 seconds and then die, let it sit for 5 min, starts again and dies, I could do it over and over again, with the same reults. Turns out there was some water in the front cover, where the coils are, and when the motor cranked it would fire initially but when the water hit the coils ( the flywheel would spin it up) it would kill it, so I cleaned the water out and it ran fine.

This may or MAY NOT help you, if it does fantastic, if it dosent, at least I tried!!

Best of luck!!!

**Bill O'Neal** · 08-02-2002, 09:34 AM

The fuel lines could be reversed. If so, the boat might start then die. It probably won't start without priming. The upper fitting on the carb is "return". lower is "on", the third one is pulse, connected to the fuel pump. The return line goes directly back to the top of the tank.

Remove the on line from the carb and crank the motor. If it has the remote pump mounted on the side of the deck, it will pump gas out of the on line while cranking if the fuel pump is good. Make sure the fuel selector valve is clear in the two positions, on and reserve. They are known to clog up.

A leaky needle and seat will fill the cases with gas. Pump pressure into the "on" fitting, while holding your finger over the return fitting. If it leaks off the pressure, you need a new needle and seat.

No need for 50 to 1 in the tank if you have oil injection too. 100 to 1 in the tank would be better.

I would get the carb working right before I assumed it needs a bottom end job.

SP · 08-02-2002, 01:08 PM

Just a hint but I went through 6 jetting changes before I pressure tested the engine.

Turns out my motor has a least one bad crank seal, the oil was coming in to the cylinder(s).

I know this is bad news and I agree to rebuild the carb(s)

The needle arm should be .6mm above the adjacent carb body surface (remove the diaghram to expose) The pressure adjustment should be of no concern to you with the older unmodified boat. 90 SP 8.5-11.5 psi pop-off with the original carb 38mm.

I agree the leak test and pop-off test should be first. And as he said, just because the needle holds pressure does not mean it's ok, pop-it off and then see if it reseats a few psi lower than pop-off.

A needle can hold pressure, pop-off, and then leak down to 0 psi. That's no good, it should seal up again a few psi lower than pop-off.

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1990 Sea Doo SP won't start.....

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