No Spark + Water Contamination(?) - 1998 Challenger 1800

[bigtexan99]

just a reminder, when you are blowing out the cylinders don't hold the starter for more than 20 or so seconds at a time, and let the starter cool between sessions. Also make sure your spark plug wires are grounded on the grounding posts or a fire could be started.

The milky stuff....sounds like oil mixed with a little water. Pour a little 2-stroke oil in a cup and add water to see. If you did ingest water into your engine it may be a little rusty in there. It might be worth the expense of a new gasket kit to open it up and clean it out.

There is a reservoir of oil in the counter balancer down by the crankshaft. Do a search on the forum to see where the 'fill' hole/bolt is for your engine. If you open the fill hole and stick a needle (kitchen gadget section of wal-mart) injection tool down the hole you can draw some fluid and see what it looks like.

 

[TurboMatt]

just a reminder, when you are blowing out the cylinders don't hold the starter for more than 20 or so seconds at a time, and let the starter cool between sessions. Also make sure your spark plug wires are grounded on the grounding posts or a fire could be started.

The milky stuff....sounds like oil mixed with a little water. Pour a little 2-stroke oil in a cup and add water to see. If you did ingest water into your engine it may be a little rusty in there. It might be worth the expense of a new gasket kit to open it up and clean it out.

There is a reservoir of oil in the counter balancer down by the crankshaft. Do a search on the forum to see where the 'fill' hole/bolt is for your engine. If you open the fill hole and stick a needle (kitchen gadget section of wal-mart) injection tool down the hole you can draw some fluid and see what it looks like.

That is correct. I was actually counting to 5 at a moderate pace while trying to clear the engine. While the amount of fluid being discharged IS less than when initially cranked, it's still there. I was going to open the throttle and spray carb cleaner in while cranking. Spark of course removed from the equation. The engine doesn't sound near as healthy and cranks slower than the starboard engine. I suspect the engine will need to be removed and torn down.

I actually found that in the manual. I believe it's the section where 1 oz of 30 wt oil is added when drained.

 

[TurboMatt]

Ok ladies and gents, I've completed my troubleshooting. I've tested about everything possible short of the MPEM. Today I tested the starboard engine harness and it seems fine. Every wires traces out perfectly with no visible damage. I checked for spark on the starboard engine using the port engine harness (as previously mentioned) and it works great. I swapped to the other voltage rectifier and we still have spark. I re-installed the starboard engine harness on the starboard engine and no spark. Tried both coils, both voltage rectifiers, etc....no spark. Traced all the wiring from the starboard engine trigger up to the MPEM and it's all good. The only thing left at this point is a faulty MPEM :-(

 

[Seadoobuddy]

Whatever part you switched over and it starts, but not when you switch them back.....then wouldn't the problem have to be one of the parts you switched?


Did you switch MPEM also???
If you left both MPEM in place and it starts then it can't be the MPEM.

Am I following this correctly???

 

[TurboMatt]

Whatever part you switched over and it starts, but not when you switch them back.....then wouldn't the problem have to be one of the parts you switched?


Did you switch MPEM also???
If you left both MPEM in place and it starts then it can't be the MPEM.

Am I following this correctly???

First off, I don't have a secondary MPEM to test with. I wish I did! I would be happy to throw someone a few bucks to let me borrow one for a few minutes but I don't know anyone local with the same boat.

The only way I have spark on the starboard engine is if I use the port engine harness and swap the starter solenoid plugs in the electrical box. So, when I hit the port start button the starboard engine rotates, make sense? At this point I have spark. So, I then tried both coils....still have spark, tried both voltage rectifiers...still have spark. If I install the port engine harness back on the port engine, I have spark on the port engine. Install the starboard engine harness on the starboard engine....no spark on the starboard engine. Tried both coils, both voltage rectifiers, etc...no spark. So, the only thing in the picture at that point is the starboard engine harness and the MPEM. I traced each wire individually from the starboard engine trigger at the front of the engine up to the MPEM with a DVOM and every wire is good. At that point, I can only assume the MPEM is faulty.

 

[Seadoobuddy]

If you are using the same MPEM but with different part AND it STARTS then the MPEM is working.

One of the parts you replaced is faulty. If the MPEM starts the motor then it is working.

Question - you have twin engines but only ONE MPEM, is that what you are saying????

 

[TurboMatt]

If you are using the same MPEM but with different part AND it STARTS then the MPEM is working.

One of the parts you replaced is faulty. If the MPEM starts the motor then it is working.

Question - you have twin engines but only ONE MPEM, is that what you are saying????

I haven't replaced any parts, yet. The port engine has spark with either coil or either voltage rectifier. To make this a bit more clear. I can hit the port starter and I have spark. At which point, I can swap the wiring to the other voltage rectifier and I still have spark on the port engine. I can then switch the port wiring to the other coil and I have spark out of that coil now, as I should.

My model boat has one MPEM for both engines. At least that's what the manual shows and how the electrical box is setup. The MPEM has trigger inputs for both engines and outputs to both coils.

 

[parrothd]

I haven't replaced any parts, yet. The port engine has spark with either coil or either voltage rectifier. To make this a bit more clear. I can hit the port starter and I have spark. At which point, I can swap the wiring to the other voltage rectifier and I still have spark on the port engine. I can then switch the port wiring to the other coil and I have spark out of that coil now, as I should.

My model boat has one MPEM for both engines. At least that's what the manual shows and how the electrical box is setup. The MPEM has trigger inputs for both engines and outputs to both coils.

I really doubt this, but did you switch the stop/stop button connections?

 

[parrothd]

Also, what happens if you disconnect the red wire from the rectifier?

 

[howie099]

Most dual engine boats have only 1 MPEM for both engines from the factory, not sure if 1/2 can go bad or not never opened one. You didn't say if you tested or swapped the trigger/pick-up coil in the front of the engine to me that is what is sounding like since you can move the harness from the bad engine to good one and it works. That tells me the MPEM is good. I would pull the trigger coil out and get a replacement. That would suck if you had a bad start/stop switch..

 

[TurboMatt]

I really doubt this, but did you switch the stop/stop button connections?

I did not try that. I imagine I would have to pull both switches out from the dash area and swap the wiring there?

Also, what happens if you disconnect the red wire from the rectifier?

Haven't tried that but I can. It's raining like crazy and probably will until Sunday so this might take a few days to check.

Most dual engine boats have only 1 MPEM for both engines from the factory, not sure if 1/2 can go bad or not never opened one. You didn't say if you tested or swapped the trigger/pick-up coil in the front of the engine to me that is what is sounding like since you can move the harness from the bad engine to good one and it works. That tells me the MPEM is good. I would pull the trigger coil out and get a replacement. That would suck if you had a bad start/stop switch..

When I swap the harness, I mean the wiring from the trigger connector up to the MPEM. So, I plug the port engine harness into the starboard trigger harness which is mounted to the front of the engine case.

 

[bigtexan99]

This may be a long shot, but does your MPEM have the fusible 5amp fuse on it? Is it burned? I've read that other MPEM's that are fried because of this fuse can be repaired.

http://www.seadooforum.com/showthread.php?18184-RFI-MPEM-5A-Fuse-blows-problem-found

 

[TurboMatt]

This may be a long shot, but does your MPEM have the fusible 5amp fuse on it? Is it burned? I've read that other MPEM's that are fried because of this fuse can be repaired.

http://www.seadooforum.com/showthread.php?18184-RFI-MPEM-5A-Fuse-blows-problem-found

I don't recall seeing one and at this point, I've been all over the wiring. There is a ~12ga wire on the MPEM that has a 15 or 20amp fuse but it's not in-line.

 

[Biffitis]

So, if you were to (theoretically) swap the port and starboard engines, then the Starboard engine (which has no spark) would now be in the Port location and have spark (assuming you left the wiring harness where it was supposed to be originally). Correct?

It's sounding more and more like an MPEM issue not seeing the triggered input to fire the coils, or the trigger signal isn't leaving the engine. I would assume that the triggers are just simple PMG sensors and should produce and A/C voltage signal upon cranking.

Also, if the engine cranks over too slow the trigger may not produce enough A/C signal to satisfy the MPEM.
I'm just thinking out loud here. Hope it helps...

 

[parrothd]

So, if you were to (theoretically) swap the port and starboard engines, then the Starboard engine (which has no spark) would now be in the Port location and have spark (assuming you left the wiring harness where it was supposed to be originally). Correct?

It's sounding more and more like an MPEM issue not seeing the triggered input to fire the coils, or the trigger signal isn't leaving the engine. I would assume that the triggers are just simple PMG sensors and should produce and A/C voltage signal upon cranking.

Also, if the engine cranks over too slow the trigger may not produce enough A/C signal to satisfy the MPEM.
I'm just thinking out loud here. Hope it helps...

I'd also check all the connections with an Ohm meter, the red wire on the rectifier is the rpm/kill wire. If you get spark with that removed it's the probably the MPEM.

If it is the MPEM you can buy a used MPEM from any 787 seadoo jet ski and wire it in. You want a 95 version, those don't have the DESS security system. You can get them on the pwctoday forum for around $100 bucks. I'd leave the original MPEM in to control the running engine and use the replacement MPEM to run the other. The only disadvantage is that you'll loose the saftey feature of being able to start the boat while in forward or reverse. The wire colors and all other electronics are the same, rec, coils, etc,etc..

 

[howie099]

I would try 787 MPEM unit. Heck can't go worng for a $100 can always sell it back off it its not it. Go to have it for testing purposes anyways.

 

[TurboMatt]

So, if you were to (theoretically) swap the port and starboard engines, then the Starboard engine (which has no spark) would now be in the Port location and have spark (assuming you left the wiring harness where it was supposed to be originally). Correct?

It's sounding more and more like an MPEM issue not seeing the triggered input to fire the coils, or the trigger signal isn't leaving the engine. I would assume that the triggers are just simple PMG sensors and should produce and A/C voltage signal upon cranking.

Also, if the engine cranks over too slow the trigger may not produce enough A/C signal to satisfy the MPEM.
I'm just thinking out loud here. Hope it helps...

That is correct. That's what I did with the wiring since it was far easier to move the wiring components. So, if all the electrical stuff (minus the trigger/pickup in the front of the starboard engine) is moved over from port to starboard, starboard engine starts and runs. After I did that I started to work backwards by swapping the MPEM coil output to the other coil then moved the spark plug wires to match the coil and the engine still ran. I then switched to the other voltage rectifier and it still ran. At that point that left the MPEM and the starboard wiring, which as I said, checked out fine with a visual and DVOM inspection.

The cranking speed is fine as the battery is constantly up to charge and the engine spins nice and fast.

I'd also check all the connections with an Ohm meter, the red wire on the rectifier is the rpm/kill wire. If you get spark with that removed it's the probably the MPEM.

If it is the MPEM you can buy a used MPEM from any 787 seadoo jet ski and wire it in. You want a 95 version, those don't have the DESS security system. You can get them on the pwctoday forum for around $100 bucks. I'd leave the original MPEM in to control the running engine and use the replacement MPEM to run the other. The only disadvantage is that you'll loose the saftey feature of being able to start the boat while in forward or reverse. The wire colors and all other electronics are the same, rec, coils, etc,etc..

I will try the red wire trick next time I make it over. The weather has been really bad lately which has limited my time on the boat. Is there any chance you can post a link to an MPEM that I would need. Maybe something from ebay?


More info: I was able to clean all the watery mix from the port engine with some brake/parts cleaner. I installed two new plugs and test fired the engine with a quick shot of carb cleaner and the engine fired right up . Now I just need to figure out the starboard wiring issue.

 

[parrothd]

That is correct. That's what I did with the wiring since it was far easier to move the wiring components. So, if all the electrical stuff (minus the trigger/pickup in the front of the starboard engine) is moved over from port to starboard, starboard engine starts and runs. After I did that I started to work backwards by swapping the MPEM coil output to the other coil then moved the spark plug wires to match the coil and the engine still ran. I then switched to the other voltage rectifier and it still ran. At that point that left the MPEM and the starboard wiring, which as I said, checked out fine with a visual and DVOM inspection.

The cranking speed is fine as the battery is constantly up to charge and the engine spins nice and fast.



I will try the red wire trick next time I make it over. The weather has been really bad lately which has limited my time on the boat. Is there any chance you can post a link to an MPEM that I would need. Maybe something from ebay?


More info: I was able to clean all the watery mix from the port engine with some brake/parts cleaner. I installed two new plugs and test fired the engine with a quick shot of carb cleaner and the engine fired right up . Now I just need to figure out the starboard wiring issue.

Try www.seadoosource.com, he's got a lot of info on mpems. I went back and check and I think all 787s have the dess security system so you'll need a key and mpem. I haven't done the swap but it should work, not sure if you can wire the two mpems together so you only have 1 key, or you'd need two. You'd have to have your current key programmed into the new mpem. Your best bet is to get used key/mpem..

http://www.ebay.com/itm/SeaDoo-MPEM...arts&hash=item43ac00f63c&vxp=mtr#ht_500wt_966