Weird fuel delivery - vapor lock? problem going on

[89seadoo]

Ok, I think this is a very weird problem and I will do my best to explain it so bare with me.

I have an 89 Seadoo and the first time I took it out after getting a tune up from the local dealer it took a good 10minutes to fire up. Once it started it would die, this went on for a few minutes. Finally it fired up and stayed running the rest of the day with Zero problems. After initially putting the ski in the water it was turned on and off a dozen times the rest of the day and it ran great.

I put it in the water a few weeks later and it fired right up withing 10 seconds, no problems.

The third time I put it in the water I noticed I was low on gas so I went to get the gas cap off and it was "stuck". I had to use the soft end of a screwdriver and a hammer to get the cap to turn and come off. I didn't think much of this and I filled up the ski with 91octante gas. Well, when I got to the river and went to fire it up it would not turn over at all. I tried for a good 10-15 minutes and the ski would crank just fine but it never even sounded like it was going to attempt to start.

Im not mechanically inclined but this is just a guess.
It seems odd that I had trouble the first time when I took the gas cap off and put gas in. The 2nd time I put it in the water I didnt take the gas cap off and it fired right up within 10secodns. The third time I went to use it AFTER taking the gas cap off it didnt fire.

Could I have some sort of vapor lock going on????

The dealer said they didnt have any problems with the ski during their test ride, I plan on taking it back there in a few days but what could be going on here? The ski originally had fuel delivery problems and the dealer replaced all the fuel lines and did a carb kit to it (and new battery)

 

[sporsterjoel]

are you geting fuel to the carbs? maybe a fuel pump problem

 

[89seadoo]

I would think if that was the problem it wouldnt have started right up for me the 2nd time.

Someone else suggested the check valve in the vent line.

Additional thoughts?

 

[sporsterjoel]

HINT, put all your seadoo's info in your avtar like make model and year so member on here will know. it sounds like your getting to much pressure in in the tank so ya the valve/baffle could be stuck id check it out

 

[Nate Surveyor]

You say several things.

Here is what I'd doo if you brought it to me, based on what you said.

Charge the batt.

Pull spark plugs, Check the plugs condition.

Crank it over, and see if oil or gas comes out of the spark plug holes.

check for spark.

If plugs are wet, see if it is oil, or gas.

if no gas, I'd prime the motor, through the carbs, and see if it fires off.

If flooded with oil, I'd think the rotary valve seals were going out.

If flooded with gas, I'd think the gas tank vents were plugged, and maybe fuel expansion forced gas into the motor, and flooded it.

Nate

 

[timmyboy76]

try fire'n it up, with cap not on...:cheers:

 

[89seadoo]

I took the gas cap off and the unit still did not start.

I pulled the plug wires from the top of the spark plugs and re-seated them. This produced no change.

 

[timmyboy76]

bypass the selector switch. get "res" line to carb.

 

[89seadoo]

Update: I have no spark.

Maybe I have tried cranking it to many times and drained the output on the battery??? Im going to put a charge on it and and see if I can get spark. (I do have new plugs as well)

 

[sporsterjoel]

Update: I have no spark.

Maybe I have tried cranking it to many times and drained the output on the battery??? Im going to put a charge on it and and see if I can get spark. (I do have new plugs as well)

does it turn over at all????

 

[89seadoo]

It cranks just fine but doesnt turn over.

I have the battery charger on it right now and when I hooked it up to test it first the battery was showing as only 30% charged. I have it on a slow 2amp charge now. I will leave it here for several hours until its closer to 100% charged (according to my meter)

The dealer thought maybe it wouldnt produce spark because the battery was to weak. I dont know. This is just something simple and easy I can do so I figured what the heck. I didnt want to pay them to look at quite yet.

 

[timmyboy76]

w/ good-charged battery, if still no spark, pull wire from coil, then retry...:cheers:

 

[89seadoo]

ok, Timmy. I got the battery all charged up and put back together. I put an in-line spark plug test in and it's showing I have spark.

Thoughts for some things to try next? Should I try new plugs in case these are all goobered up or something??????

 

[89seadoo]

Can I spray some starting fluid and see if it will then start?

What do I use and where do I spray it? pics?

 

[Nate Surveyor]

It cranks just fine but doesnt turn over.

I I didnt want to pay them to look at quite yet.

It may pay you to have THEM look at it!

(You are officially posting oxymorons!)

How does this work?



Nate

 

[89seadoo]

Ok, first off I would like to thank everyone who has helped so far and beared with me. This has been a learning experience on my part and I have learned alot so far.

I followed your list Nate and here are the results:



Here is what I'd doo if you brought it to me, based on what you said.

Charge the batt.
done

Pull spark plugs, Check the plugs condition.
I did this and was shocked to find they are NGK plugs after the dealer told me they changed them. The NGK plugs match the old NGK wires and I would think the dealer would use Champion (see pic - this pic is of the OLD plugs before I put in new)

Crank it over, and see if oil or gas comes out of the spark plug holes.
I did this and nothing came out. I looked in there with a flash light and it appeared dry

check for spark.
spark is good.

If plugs are wet, see if it is oil, or gas.
I put the new plugs in and after cranking it a few times the plugs are dry

if no gas, I'd prime the motor, through the carbs, and see if it fires off.
I cant find my allen wrench to get at the carb but I will do this next


How do the old plugs look?

 

[sporsterjoel]

Ok, first off I would like to thank everyone who has helped so far and beared with me. This has been a learning experience on my part and I have learned alot so far.

I followed your list Nate and here are the results:



Here is what I'd doo if you brought it to me, based on what you said.

Charge the batt.
done

Pull spark plugs, Check the plugs condition.
I did this and was shocked to find they are NGK plugs after the dealer told me they changed them. The NGK plugs match the old NGK wires and I would think the dealer would use Champion (see pic - this pic is of the OLD plugs before I put in new)

Crank it over, and see if oil or gas comes out of the spark plug holes.
I did this and nothing came out. I looked in there with a flash light and it appeared dry

check for spark.
spark is good.

If plugs are wet, see if it is oil, or gas.
I put the new plugs in and after cranking it a few times the plugs are dry

if no gas, I'd prime the motor, through the carbs, and see if it fires off.
I cant find my allen wrench to get at the carb but I will do this next


How do the old plugs look?

use what ever kind you manual stats for plug type.... ALSO i would check your plug gaps 3rd pic kinda looks like to small of a gap, could just be the angle of the pic but id double check it...

 

[89seadoo]

The pics are of the OLD plugs. The manual states to have them gaped at .020 (which is what I set the new ones at) The old ones came out gaped at .025

Manual says to use Champion plugs



Im going to guess and say that once I spray some starting fluid in the carb it will fire right up. If my new plugs are staying dry is it safe to assume that this is a fuel delivery problem? If so, then what?

 

[Nate Surveyor]

Buy yourself some silicone spray lubricant, with a tube on the on the end, (WD 40 would probably Doo it) And, on the TOP of the spark arrestor, (Which is held on with the allen screws) you will find a little black PLUG. Carefully pull this puppy out.

Now, you have an open HOLE about 1/8" dia, down into the tops of the carbs.

Spray a 2 second burst of silicone spray, or WD 40 down it, and then crank it over, and see if it fires. If it does, then your problem is NO FUEL.

Nate

 

[89seadoo]

Attached is a general overview of my engine, I looked in my shop manual but I couldn't find any reference to a spark arrestor. (I'm sure this is a common term but Im still learning with the terminology and what things look like)

I drew three arrows, which area is the closest to the spark arrestor?
A might be the obvious answer but B is where the carbs are.

Instead of spraying WD-40 I have starting fluid, shouldn't be a problem using that right?

EDIT: I think I found it - http://en.wikipedia.org/wiki/Spark_arrestor
Is this the mesh/screen that is found above the carbs? If so, when I took the air box off I could see it when I looked into the hole. Im guess I need to take the top part off of area "B" and I will then see the mesh spark arrestor. This is where I shall then see the plug ??

 

[seadoosnipe]

.....587cc Rotax.

It seems your learing a lot about your ski. It also sounds like your not getting any fuel to your carbs. Either your fuel pump is not working properly, a check valve or your pulse line diaphragm is bad. Your needle valve may not be opening to let gas into your fuel chamber. If this is the case, then from what I've read, your mechanic that did your carbs, didn't set them properly. Take it back to him and tell him your spark plugs are dry and that indicates that after you (he) did all the work, he didn't set the "pop off" correctly in the carb. Make sure you use the word "pop off" pressure is incorrect.

Get rid of the 91 octane fuel You should be using 87 octane. The added heat from the higher octane is not good for that engine and can cause detonation.

Your spark plugs are NGK plugs. NGK BR7ES set at .024"

If you want to check the theory on your fuel being the problem (dry plugs say your not getting gas) take out both your spark plugs and pour a little of your fuel mixture in each hole. If your still using oil injection, then get a little premix fuel from your weed eater or chain saw to use. It should have a close ratio for what you need. Give it a try. If the engine ignites and dies, then you got a fuel delivery proplem.

DO NOT USE STARTING FLUID.........the starting fluid has no oiling properties and can cause internal damage to bearings and rings.:cheers:

 

[Nate Surveyor]

Mr. Sniper has it. :agree: I get too wordy and confuse you.

And, please, don't use starting fluid! Not only does it lack lubricating properties, it is way too hot! You can destroy an engine with it!

If you EVER use that stuff, use it on an OLD tractor, or some engine other than a Sea Doo! In fact, I could NEVER recommend using it on 2 stroke motors.


I Probably confused you with the "Spark arrestor" thing. The Flame arrestor is indeed the screen, that the intake air goes through, on it's way into the carb(s). The idea is to prevent a backfire from igniting vapors under the seat. That is what the flame arrestor is for. So, it is sort of backwards of a motorcycle, which has flame arrestor on the exhaust.

This has flame arrestor on the INTAKE. There is a black plastic cover over this flame arrestor. In the top of this black cover, is the little rubber plug, which is used to FOG the engine, with anti corrosives. This is a handy place to prime the motor.

Nate

 

[89seadoo]

It seems your learing a lot about your ski. It also sounds like your not getting any fuel to your carbs. Either your fuel pump is not working properly, a check valve or your pulse line diaphragm is bad. Your needle valve may not be opening to let gas into your fuel chamber. If this is the case, then from what I've read, your mechanic that did your carbs, didn't set them properly. Take it back to him and tell him your spark plugs are dry and that indicates that after you (he) did all the work, he didn't set the "pop off" correctly in the carb. Make sure you use the word "pop off" pressure is incorrect.

Get rid of the 91 octane fuel You should be using 87 octane. The added heat from the higher octane is not good for that engine and can cause detonation.

Your spark plugs are NGK plugs. NGK BR7ES set at .024"

If you want to check the theory on your fuel being the problem (dry plugs say your not getting gas) take out both your spark plugs and pour a little of your fuel mixture in each hole. If your still using oil injection, then get a little premix fuel from your weed eater or chain saw to use. It should have a close ratio for what you need. Give it a try. If the engine ignites and dies, then you got a fuel delivery proplem.

DO NOT USE STARTING FLUID.........the starting fluid has no oiling properties and can cause internal damage to bearings and rings.:cheers:

Thank you everyone, you guys rocks!

I will try putting some gas in the spark plug holes and seeing what happens.
This entire problem baffles me because it ran great the first time out, started right up the 2nd time out and didn't act up until I took the gas cap off.

I think I might try taking the fuel line off of the carb and trying to start it (checking for fuel flow) and also maybe try taking the fuel line off of the pump and checking for flow. (I just want to do my homework and testing before I bring it back to the dealer - if the problem is something besides the carb they will charge me for it - as they worked on the carb and not fuel pump for example)

How would I go about checking the "check valve"?

 

[89seadoo]

I haven't done any of the above yet, been busy with life but it's on my list.

I was thinking about maybe doing this and wanted to get everyone's input first.


If you consider the fuel tank as POINT A and everything it connects to as POINTS B, C, D, E, F etc, etc, etc.

Should I take the fuel lines off of all the other points, leave the other ends connected to the tank. Fill up the tank with gas, put pressure on it with my hand so I can then "flush out the lines" ? Would this even be worth while????

How can I tell which line is my "vent line" so I can look for a check valve too.

 

[Nate Surveyor]

Originally Posted by Nate Surveyor

Here is a repost, for your benefit:

I have a 1998 GX. Here is the fuel path on the GX. Yours should be similar:


-----------------
...first, I assume that you have removed all the gray fuel lines, and done a proper burial for them? (that is 6' deep, and pack the dirt back over the spot, and then pee on it!)

Then, get new black ones. I am an overkill kind of guy, so I replaced the vent lines too. And, I got the 3.99 a foot stuff for EFI cars. That comes to about 100 bucks to replace the fuel line! (gasp!)

Fuel path is like this:

Starting at the VENT hose, on the side of the sea doo, there is a check valve, that only allows air to enter. then go in to the T fitting, where the line intersects with a line coming from just in front of the seat, where there is a little rubber plug. These lines have to be open to flow.
Back down to the T, then it goes down into the baffle, and inside the top of the tank.
Now, FUEL enters the bottom of the baffle, and goes through a screen. This is a little plastic screen, that collects GOOP from those gray fuel lines, and saves it for the day that it can shut you down, when you are far away from the boat launch site. Fuel then goes up the baffle, (through the RUN side, which is about 2" up off the bottom of the tank) and goes to the top of baffle, to the fuel select valve, where it intersects the hose from the RESERVE side, DEPENDING on the fuel select valve. (The reserve side comes from about 1/2" off the bottom of the tank, and up to here) Then, the fuel goes to the water trap, which is accessed through the trunk, behind the fire put out device. Otherwise known as a fire extinguisher. The fuel goes through this water trap and screen filter, then back to the engine through the MAIN FUEL FEED LINE. At the engine, it enters the pump, and is pressurized to just the right pressure, to keep the engine fed at any RPM. Then, extra fuel goes back to the tank through a fuel return line, and in the top of the baffle.

INSIDE the carb, in enters from the pump, which is activated by pulses from the crankcase, and goes through the LAST filter. This guy is usually clogged up. There are pics of it all over this forum. JPX posted a good pic of it recently. Gotta clean this little filter all the way.

So, you had a breakdown in the fuel system somewhere?



Nate