Last year I bought a 1995 Seadoo Speedster. It was in rough shape and this year I decided to overhaul the whole boat. I rebuilt the motors, and changed the whole appearance of the boat. I am having trouble with one of my engines though. It will idle for a little bit, then slowly stall out. My guess was that it isn't getting fuel fast enough (bad filter?) are there any common problem with this boat that I am not aware of that would cause this? As for the electrical problem I installed two digital Tach gauges. They work, but only for about 30 seconds or so then they shut off (same thing with the fuel gauge). Thanks for your help!
-
This site contains eBay affiliate links for which Sea-Doo Forum may be compensated.
1995 Speedster Electrical/Engine Help
- Thread starter MrMoonPie
- Start date
- Status
Waterluvr
New Member
That's the exact duration for the MPEM to time out power from pressing the start / stop button without the MPEM having been reset. Make sure you're pulling the DESS key if the motors have been off for more than five minutes and re-attach it. You should hear two beeps and the system should remain powered up while the motors are running and until such time you press the stop switch or remove the DESS.
Alright little update. The wiring is all sorts of messed up from the previous owner, I've done my best to fix it and got it (last year) so I could run the boat and keep it running then shut it off when I needed too. So the dess trick didn't work. But my major concern is the engine stopping after idleing for a bit or riding for a little while. I rebuilt the carbs and replaced the fuel line from the filter too the carbs and have the same exact problem that I was having before. In the spring I rebuilt the top end of both motors and that was it didn't mess with any other engine components. Please help, I am at a loss on what to do.
Waterluvr
New Member
There are many things on the electrical side that can cause it, but you'll go crazy chasing ghosts if you don't diagnose whether you have a complete secondary ignition pulse firing your plugs at the time the motor dies out. It may be a fuel issue, and if so there's a laundry list of things to start with and cross off the list as you go starting with the fuel supply side of things.
It's really important you determine at this point if you do or do not have ignition when the issue arises, in your case when the motor cuts out I would simply attach both plug wire boots to a Stevens marine CDI rated ignition tester, attach the ground lead to the plug resistor and verify both wires are firing over the electrode gauge when you crank the engine over.
From that point if it passes we can move on to your fuel system for diagnosis.
It's really important you determine at this point if you do or do not have ignition when the issue arises, in your case when the motor cuts out I would simply attach both plug wire boots to a Stevens marine CDI rated ignition tester, attach the ground lead to the plug resistor and verify both wires are firing over the electrode gauge when you crank the engine over.
From that point if it passes we can move on to your fuel system for diagnosis.
Attachments
So I haven't gotten an ignition tester yet, but I've done a few tests so far. I switch all of the wiring from one engine to the other and the same engine cut out. So I think that tells me that the wiring is alright, and the mpem isn't messing with it (I think this, I don't know much about mpem's or what they control) I then proceeded to switch the fuel supply from one engine to the other and still the same engine cut out. With this I think I've narrowed the problem down to something internal? Does this sound right? Maybe something to do with the ignition timing getting out of sync or something? Please let me know if there are any flaws in this. I am a high school internet mechanic so my knowledge base is not very large. Thanks!
Waterluvr
New Member
Your timing is fine. It wouldn't start, idle and achieve WOT in combination as desired at any point were it an issue. You have an ignition problem, or a fuel issue provided your compression is within specs.
Go back and read post #6 again about chasing ghosts. There are numerous tests to perform once you answer the question asked regarding if you do or do not have ignition at the time the motor cuts out.
Go back and read post #6 again about chasing ghosts. There are numerous tests to perform once you answer the question asked regarding if you do or do not have ignition at the time the motor cuts out.
Waterluvr
New Member
Um no, it might run ok but 135 is pretty far from fine on a fresh rebuild. In fact that's the point where I would be concerned about piston/ring/cylinder clearance's as that is 10% below spec and 5% from the point where I would perform a top end removal and take critical wear measurements for replacement.
Maybe it's just your gauge? Always good to double check with one that's been calibrated.
On Edit: You did reference the size of the base gasket and use same to get the squish back to where it belonged? That could be the source of your trouble there as well.
Last edited by a moderator:
Waterluvr
New Member
That's perfect then, right where you need it to be.
Well I tested the spark and it wasn't firing. Then I remembered I had a very similar problem on one of my snowmobiles a couple years ago, was a bad ignition coil. And when I switched the electrics on the boat I just swapped wire going into the coil, not the actual coil itself. So I swapped the coil and sure enough the other engine died. Great a bad coil easy enough fix. So I ordered two new coils and put them in. Took the boat out this weekend and now I can't get either motor to rev past 3k then the port motor dies after a minute. There was one time where I was able to get the starboard motor to rev fully and the port motor to 3k, but most of the time neither motor would rev high. (I'm getting no signal for my tach on the starboard motor).When the port motor is off I can get the starboard motor to rev consistently. I installed a fuel filter on the line going to the carb so I could see if it was getting enough gas and it was. So fuel isn't the problem. Now the motor doesn't slowly sputter out, it just dies on me which makes me believe that it is an electrical problem. Would there be anything inside of that magneto housing on the back of the motor (not sure if thats what it is called on these things) that could cause this? Loose wire or something?
hotrodssnova
Member
From what I have read, in the manual, the only way to shut these engines of is:
1 remove ground from ignition system
2 stop fuel flow to engine
3 engine overheating and causes piston to expand and 'sticks' in cylinder. ..aka quick stick.
The temperature sensor is directly attached to the buzzer thru the mpem. If you probe your temp sensor wire and the tan wire off the mpem you will see continuity. The buzzer activates when the sensor gets hot enough to complete a ground circuit, activates the buzzer.
It has no effect on engine performance.
1 remove ground from ignition system
2 stop fuel flow to engine
3 engine overheating and causes piston to expand and 'sticks' in cylinder. ..aka quick stick.
The temperature sensor is directly attached to the buzzer thru the mpem. If you probe your temp sensor wire and the tan wire off the mpem you will see continuity. The buzzer activates when the sensor gets hot enough to complete a ground circuit, activates the buzzer.
It has no effect on engine performance.
- Status
Similar threads
