96 Speedster 1 engine runs 1 does not

[Mitch619911]

So we got the starboard side engine to fire up and runs super great (always starts right up) but the port side engine is not wanting to start.

It just keeps cranking and cranking, it has a spark I don't know if it's weak or normal, we switched spark plugs with the running engine and that did not work (the other plugs work fine in the good engine).

The engine did want to start a little bit but it just dies, probably fires 2 times, when we first got it out it was running but kept shutting down after a few seconds (10s to 60s?). The good engine ran but it seemed like when we started the bad one they both died... Good engine seems to run fine without the bad one trying to start.

We did try starting fluid directly into the cylinder and it seemed like it did not want to start (but it had spark?!?) last we tried it wanted to start for 2 seconds then die and we have up and took it home.
Also before we brought it to the ramp they both fired up and ran for a good amount of time.

Could it be the dess? Mpem? Main brain? Any questions or answers would be very helpful, we intend to try to keep working on it tomorrow!
Thanks everyone!

 

[JeremyD615]

First thing, don’t use starting fluid on your boat. It doesn’t have any lubricating qualities and can wash the oil off of the cylinder walls and bearing surfaces. If you need to prime the system, use a spoonful of premixed gas in either each of the spark plug holes, or right in the carb throats.

Second, how are your batteries set up? Do you still have two small batteries, or one large one? Make sure they are in good condition and fully charged.

Third, when is the last time you went through the carbs on that motor? An intermittent shutdown is usually a symptom of dirty or plugged up carburetors, and of course as this progresses it can cause hard starts as well.

 

[Sportster-2001-951C-Stock]

I've seen starting fluid lift the head off the block before, pre-mix in a pump squirt bottle is my primer of choice.

 

[jts32]

First thing I would do is test compression. If that is ok, move on to the fuel system.

Basically all these motors need to run are fuel, compression and spark. You've got spark, so check the other two

 

[Mitch619911]

First thing I would do is test compression. If that is ok, move on to the fuel system.

Basically all these motors need to run are fuel, compression and spark. You've got spark, so check the other two

Took the fuel filter off and drained it put it back on and tried to start it and used a bag trick to cover the intake filter so it would pull the fuel into the carb..etc. then took the fuel filter off again and it had fuel in it, so I know its getting fuel to the filter but how could we check fuel to the carbs easily? They seem like a pain to get to.
It has compression (just don't know how much psi), will try to test that.

Could it be that the plugs are bad? They were brand new, could that engine foul the plugs maybe flooded them while we were trying to get fuel to the engine? (we did switch plugs on both engines and the plugs in the bad engine ran fine in the good engine)

Thank you for the replies!

 

[JeremyD615]

You could visually test by adding a section of clear fuel line on the return line coming off the carbs, but if it’s pulling fuel into the filter, it’s pulling it into the carbs. You really need to verify your compression, 150 is perfect, 120 is a dead motor. Once that’s done and you have decent compression numbers, you need to go through the fuel system.

 

[Mitch619911]

First thing, don’t use starting fluid on your boat. It doesn’t have any lubricating qualities and can wash the oil off of the cylinder walls and bearing surfaces. If you need to prime the system, use a spoonful of premixed gas in either each of the spark plug holes, or right in the carb throats.

Second, how are your batteries set up? Do you still have two small batteries, or one large one? Make sure they are in good condition and fully charged.

Third, when is the last time you went through the carbs on that motor? An intermittent shutdown is usually a symptom of dirty or plugged up carburetors, and of course as this progresses it can cause hard starts as well.

One large battery, it was fully charged.
Would have been a very long time since anyone has been through the carbs, I don't think they are clogged, we had it running out of the water for a moment.

Will try to test the compression today.

 

[jts32]

Not sure if your fuel pumps are on the carb or stand alone type? My Challenger has the pump on the carb, my Challenger 1800 has stand alone. If your pump is on the carb, then you should be getting fuel to the carb since it is pulling fuel to the filter. If it's a stand alone pump you can pull the IN line off the carb and turn the motor over to verify fuel flow.

You can try pouring a little premix down the plug holes and see if it will run for a few seconds. If it does, I would say you have a fuel issue and start with rebuilding the carbs. If it won't run, you have another issue, most likely compression or timing

 

[JeremyD615]

How the boat runs out of the water won’t tell you anything about the health of the engine or fuel system. When you run the boat on the trailer, you have no load on the motor, and even at high rpms, you’re pulling very little fuel through the carbs. You’ll hit the limiter before the carb ever comes up on the circuits that may be plugged up. I’d highly recommend that you buy some genuine OEM Mikuni carb kits and go to town on rebuilding and cleaning those carburetors. Follow the sticky in the 2-stroke PWC section.

 

[Mitch619911]

UPDATE:
Might be fixed!

On the fuel in line that connects to the 2 carbs it was being held on with a zip tie and was leaking (took the lines off the fuel switch and blow in them and saw it leaking).

We put a hose clamp on it and got it nice and tight and it fired right up.
Taking it out tomorrow to see if that fixed it and if it runs fine on water.
Also: on the DESS wires, one of the wires was ripped off but hard to notice, we pulled on it and little bit and it came out (it had a butt connector on it, put a new one on).

 

[Raven888]

Sounds encouraging. I love cheap, easy fixes. Good luck and happy boating!

 

[Mitch619911]

Also had a quick question, does anyone else experience sucking anything in from the water and clogging up the jets on the underside (intake?) of the boat?

 

[JeremyD615]

Also had a quick question, does anyone else experience sucking anything in from the water and clogging up the jets on the underside (intake?) of the boat?

Absolutely! It depends on what body of water you’re on, but if there is a lot of vegetation or debris, it’s extremely common to suck something up and get major cavitation...

 

[Sportster-2001-951C-Stock]

My boat ramp is currently covered in sunken leaves, better push off if you intend on launching a jet there.

To leak check fuel system, I disconnect the tubing connection at fuel pump and blow back through towards the fuel tank.