98 Speedster issues-HELP!!!!!!!!MPEM???

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Phildoo

Phildoo

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Just bought a speedster and having issues with it. Only one engine will start and run.
We have:
Checked every possible fuse known to man-NONE blown
Ohmed and checked continuity
Swapped starters-Both good
New solenoid
Solenoid jump with turn engine over fine
Getting continuios tone when lanyard attached.
Took to dealer, said wont be a dess problem because it starts good engine.??
Start button is fine.
Lanyard is not the one for the boat,but other owner said it used to start both engines, dealer said it doesnt matter.
Has one MPEM.Can this be the problem? even though one engine works fine?

Other issue:
Hurling oil from front cylinder on engine not running. Rave valve?
 
Is that engine cranking? The same lanyard starts both engines. DESS and MPEM probably not the problem. IF you arent even getting it to crank. Have you check the start button for that motor?
 
Not thru the start button, get nothing,not even a click. Can jump solenoid and engine will turn over. Swapped start buttons and both work fine
 
Update

Sanded key and post so now continious tone is gone.
Removed MPEM and looked at back carefully and see no burnt areas.

Any way to test MPEM?
 
You mentioned oil in one of the cyls, this is normally caused by a crank seal leaking and it also happens a lot in the off season as oil seeps slowly past filling the crankcase, many times you can remove the plugs ground the wires and crank out the oil then restart and you will see some strong smoke clouds forming, if it leaks in to cause this trouble in a 2 week period of not running then it is crankshaft time. Testing the mpem regarding starting can be accomplished by taking off one spark plug wire and sitting a known good plug on that wire and crank to see the spark jumping, there is also a lighted gizmo that many small engine shops have on-hand that clips on one plug wire and clips over the existing plug in the motor - I have one but where I purchased it 25 years ago escapes me, if you have seen someone at a marina use this ask them because it makes this test so much quicker. And remember the compression test is the first thing in 2stroke repairs.
 
Thank you for that information. It should prove valuble to me when I can get past the main problem of engine will not turn over via start button. It will only turn over by jumping solenoid. Does the MPEM control the starting and ignition? We have tested wiring and are getting power to the MPEM but not seem to get power coming out of MPEM for that starting solenoid for the motor that won't turn over. Other motor starts and runs fine. Start buttons are good also. Fuses haven't blown once.
Any ideas??
 
You might want to check the wiring doing to the selonoid, there might be corrosion in a plug along the way. I would unplug all the connectors and put some dielectric grease on them all..
 
Me Too

It seems like I may also have this same issue with my 1997 Speedster.

The trouble began with really faint beeps (almost silent) and only the left engine would crank and start and right would do nothing. All the fuses checked good for continuity, but it wasn't until I replaced the 5A fuse in the bilge that the beeps started coming in loud and clear. Replaced all fuses fore and aft and no change.

I swapped the starter switches in the front area and both switches would start the left engine fine so don't think it's the switches.

I took a hefty piece of wire and jumped the terminals for the solenoids and both left and right engines crank. Still nothing (no cranking) when pressing the start button for the right engine.

Don't mean to hijack your thread, but seems like we've got the same issue and would like to get this boat on the water for the weekend fun!
 
Thanks harley2rde for the idea. I switched the plugs to the solenoids and the left start switch starts up the right motor fine so I believe that clears both solenoids of trouble which is consistent with Phildoo's problem in that he replaced the solenoid and still has the problem.

So looks like a bad MPEM...

I'm toying with the idea of installing a toggle switch between the two solenoids so that when I hit the left engine start button I can control which engine it goes to. Ideally the switch should not be in the bilge and wired up front.
 
Pretty sure it's the MPEM but not 100%. Have a mechanic comin this week to confirm. Hope it isn't cuz it's 1700$ for a new one. Yikes!!
Will let you know what he says.
 
The black wire going to the solenoid should go to engine ground at all times. The MPEM supplies 12 volts to the Y/R wire, when you hit the start button, in order to engage the solenoid. If there is no voltage going to the Y/R wire I would use a ohm meter to check the Y/R wire for a open between the solenoid and the MPEM before I would condemn the MPEM.

DAWG
 
Dawg
that is very very informational about that black wire. I have seen a older post about a guy who said he fixed his problem because he had reversed black wire and ground cable???... Was very baffled by this. Didn't know if it was just mis-information or what. But we tried playing around with that black wire by grounding it to the engine.. Not very well, bur enough to complete I current we believe. Not 100% sure though. Should it be to the engine or battery???
 
Dawg
that is very very informational about that black wire. I have seen a older post about a guy who said he fixed his problem because he had reversed black wire and ground cable???... Was very baffled by this. Didn't know if it was just mis-information or what. But we tried playing around with that black wire by grounding it to the engine.. Not very well, bur enough to complete I current we believe. Not 100% sure though. Should it be to the engine or battery???
 
Either the engine or battery neg post will do. Do you have 12 volts going to the Y/R wire when you hit the start button?
 
mpem most likely bad . did away with my starting system and just used a toggle switch from bat to y/r wire and still use start stop buttons for stop . wasn't buying a mpem !!!!! when my mpem took a crap in cranking system it fried the starter . cranked till wires melted while i was away from boat . what a crappy system .
 
Its official. Bad MPEM. So now the search for a replacement.
Anyone with connections or know of a boat yard who might have one?
 
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