98 speedster mpem

[scryc0268]

I have a 98 speedster and the right motor will only fire up typically (especially on cold starts) after running the left motor for 10+ minutes.. All fuses have voltage except the engine control.. Could this be the diode? Any idea where its located?

thks

 

[scryc0268]

who can i pay on here for some help???

 

[99spxxx]

I may have one.. pm sent...

 

[scryc0268]

Unfortunately its the wrong one... Anyone else have any ideas? Does msd have a unit to replace this? Or can it be repaired? Or is it broken? thks

 

[jhjesse]

What checks have you performed to make you think it is electrical?
Battery weak??
Sure it is not fuel related? (Baffle screen partically clogged)
Checked for spark?
Checked compression?
It has been my experience over the years that electrical problems are usually not intermittent. Electrical parts either work or not at all.

 

[scryc0268]

New interstate battery checks out..
Fuel is good - it runs great once started.
No spark until I run left for 10 plus minutes.
Compression 165 on all 4.
Thks

 

[scryc0268]

Coil, stator, flywheel good. New spark plugs and fuel. Voltage on all fuses except engine and gauge control although I'm not popping the infamous 5 amp fuse...

 

[jhjesse]

New interstate battery checks out..
Fuel is good - it runs great once started.
No spark until I run left for 10 plus minutes.
Compression 165 on all 4.
Thks

New one for me.
I think that you can rule out the MPEM because both engines eventually run.
No spark on the right engine until the left engine runs for a bit...
Have you tried starting the right engine first?
Have you tried switching the coils?
Once you have the engines running have you checked voltage across the battery terminals? 12.5v to 13.5v
Inside the voltage box where the two coils are located are two 15 amp fuses. Might check those fuses. If you have not already done so, might check all electrical connections and make sure all are clean and tight.

Good luck

 

[BMANN06]

What does the other motor do when attempting to start with other motor not running.

Not starting is not descriptive enough.

 

[scryc0268]

Yes, ive triied starting the right first but no go.. Yes triied switching the coils.. All connections have been checked. The boat was previously boosted... oops.. The right will always turn over but never catch. As previously stated I have no voltage on the engine control fuse in the mpem. Not until approx 10 minutes after running the left is there any spark on the right. Although sometimes the left dies while triiing to start the right and I need to wait 5 minutes before either will turn over and go again (I assume this is just the battery going low due to triing to start right for so long). Once started runs great! Any help would be appreciated. I dont want to spend that much coin for a mpem if it wont solve the problem. Thanks!

 

[speedster98]

Just to check, pull the battery and take it to a parts store to have it load tested. I have seen new batteries fail for many reasons. A load test will put it under stress and any weaknesses will be shown. Parts stores usually do this for free, that's a pretty cheap and easy fix compared to replacing stuff till it works or going to a stealership. If you do have to get a new battery get a high quality one. Mine is 675 cranking, 140 reserve and never has given me a problem.

 

[99spxxx]

Unfortunately its the wrong one... Anyone else have any ideas? Does msd have a unit to replace this? Or can it be repaired? Or is it broken? thks

Have the right one now pm sent

 

[mikweb]

I have a similar problem only no power to right motor. What ended up being your problem?

 

[flaminr6]

I have the exact same problem on my 98 speedster. I've changed the stator, pick up coil, have swap coils from one motor to the other and nothing. It will eventually fire after the Port motor has ran for 10+ minutes.....seems like I have no spark on starbord engine initially. once I get it fired it is good all day......I am entirely lost! Everything tests OK as per the service manual but she just doesn't spark.

What ended up being your issue ? I am fearing it may be the MPEM

 

[scryc0268]

Unfortunately it was the mpem.. I got one from handpicked parts in florida.. work in perfect now. Sorry. I see there's an mpem conversion coming out soon.. good luck

 

[Dr Honda]

I have the exact same problem on my 98 speedster. I've changed the stator, pick up coil, have swap coils from one motor to the other and nothing. It will eventually fire after the Port motor has ran for 10+ minutes.....seems like I have no spark on starbord engine initially. once I get it fired it is good all day......I am entirely lost! Everything tests OK as per the service manual but she just doesn't spark.

What ended up being your issue ? I am fearing it may be the MPEM

The reason you weren't getting help or answers... other than from the OP... is because you should have started your own thread.


But... it looks like you guys have the EXACT same issue. Electronics don't normally do what you are describing. It almost sounds like there is an issue in the "Logic" of the microcontroler.


As far as repairing it... Who knows. If you want to try to rip away the potting material, and see if there is any damage... that would be a good place to start.

 

[flaminr6]

Thanks Dr Honda

The reason you weren't getting help or answers... other than from the OP... is because you should have started your own thread.


But... it looks like you guys have the EXACT same issue. Electronics don't normally do what you are describing. It almost sounds like there is an issue in the "Logic" of the microcontroler.


As far as repairing it... Who knows. If you want to try to rip away the potting material, and see if there is any damage... that would be a good place to start.

Thanks for the advice! What a C on the hunt it was to remove the potting material! It paid off though it revealed a circuit on the printed board that was shorted! It should be an easy fix with a little solder and a small piece of wire.