95' sportster - all sorts of issues getting desperate

[r3cc0s]

I'm almost ready to pull the plug and junk the boat.

The hull is in good shape, and last year I did a whole ton of work to fix my mistake of pouring water into the fuel tank through the tank breather, as someone told me that was how to flush the jet.

Syphon'd the water, the cylinders still have okay compression (135/336) and ran well until I got a pebble stuck into the cooling system that we replaced all hoses and the exhaust/ypipe and water box until we realized it was stuck inside of the jet itself.

Boat ran well rest of the seasons.

Fast forward to this year:

Fully covered, winterized with no issues, no oil leaks, carb looks fine, no water in the water seperator... so mechanically everything is good. Pump is in good shape
Wouldn't turn over... had to replace the Stater soilnoid

Wouldn't charge... had to replace the rectifier, still didn't work, so replaced the stator

No when it starts, which it does... it just beeps at the fuel guage, and then it dies... like hard.

Checked the spark and it seems to be not sparking at wide open throttle but is okay below it....

So, my mechanic is saying to replace the coil and possibly the mpem...

I was going to buy both but I cannot seem to find a part# for an mpem for this specific boat with the 657x....

ugh... i don't know what to do, I haven't even got her on the water this year.

 

[IDoSeaDoo]

Dang dude, tough luck :/ I take it you have just the single 657x? I assume you've changed out the plugs with new ones?

When you say it "just beeps at the fuel gauge" is that after it's running? These boats are very simple. A beep indicates an error, and the only one I can think of is the overheat sensor. Have you tried just leaving that disconnected? Also, it can beep if your neutral safety switch is malfunctioning. It limits RPM in Neutral (and maybe reverse on some models) It'll also not allow you to start when the boat is in FWD.

How are you testing for spark at WOT? Inductive timing light? Have you tried checking to see if your new rectifier is bad? Open the electrical box and just unplug the red-wire. It'll still run, just not charge. What are your volts while running btw?

If you have just the single 657x, it'd be pretty simple to swap a 720 MPEM in there, but I think you'd have to also use its wire harness as the boat has a neutral safety switch and a different kind of electrical box/plug. If you really want a fun challenge, drop a 4tec in there It'll be a crazy boat, as light as it is. I did it to my 97 Challenger (like yours but with a 4th seat), and it's such a fun boat now!

 

[Dr Honda]

Yep... that sux. But hang in there... we will help you sort it out.

I'm not sure about the fuel beeping thing. Can you post a vid of how it starts and dies?

 

[r3cc0s]

The boat is at the lake and after talking to some other tech's in town who are seadoo/BRP skidoo guys, they think with this 657x it must be the CDI/MPEM at this point.

Random beeps that die, that are not associated to the heat sensor or fuel sensor (nor would they cut spark) is likely the CDI at this point...

too bad we replaced pratically everything else: stator, solenoid, coil relay etc..

chances are this: my hull wasn't completely empty and in fact had alot more water in it due to the leak on my tuned pipe (at the clamp)...

though winterized it correclty and tried to empty the bildge as much as I could (tipping the boat as much as I could), there was too much of a temp difference throughout the winter causing condensation killing many of the eletrical components in the mpem box...

flame arrestors, fuel system, Carbs, cylinders, the rest of the exhaust seem to be fine...

only other thing is possibly the fuel selector getting gummy, but we doubt that at this point...

anyone know if I should buy a "new" CDI from BRP or find something aftermarket or a used one from say an XP?

 

[r3cc0s]

?

 

[Dr Honda]

Sorry I missed your responses.

When you replaced the stator... did you replace the entire thing... or just the charging coil?

Generally... if you have an issue with the MPEM... it's not intermittent. SO... since it's working... I'm going to go out on a limb, and say it's fine. BUT... since you had a bunch of water in the box... I would say to pull every plug... clean all the connections... and put them back together so there is no potential issues.

Next... your CDI is part of your ignition coil. YES... it can be going bad, and can't keep up with the higher RPM's. BUT... since you had the MAG apart... I would go back in there, and make sure there aren't any wires rubbing, and grounding.

Finally... since you have an early boat... the MPEM control is relatively simple. It controls the kill and rev-limit by grounding the wire between the ignition coil, and the MAG coil behind the flywheel. SO... a quick way to eliminate where the problem is... is to disconnect that wire. On the Schematic, it says its Black/Red/Green. But I don't think it's a double trace. I'm guessing it's just Black with a red stripe.

SO... if you pull that wire off the MPEM... and you still have an issue... it's either the MAG or ignition coil. (And the MAG coil is easy to check) If the problem goes away... it's the MPEM.


Oh... that wire is your "Kill" wire. SO... you may want to hook up a long wire so you can actually shut off the engine as the key won't do it. Just touch it to a ground. but be careful... that's relatively high voltage when the engine is running. The other way to shut it down is to pull the choke. That's safer, but will make it hard to restart.

 

[r3cc0s]

Sorry I missed your responses.

When you replaced the stator... did you replace the entire thing... or just the charging coil?

Generally... if you have an issue with the MPEM... it's not intermittent. SO... since it's working... I'm going to go out on a limb, and say it's fine. BUT... since you had a bunch of water in the box... I would say to pull every plug... clean all the connections... and put them back together so there is no potential issues.

Next... your CDI is part of your ignition coil. YES... it can be going bad, and can't keep up with the higher RPM's. BUT... since you had the MAG apart... I would go back in there, and make sure there aren't any wires rubbing, and grounding.

Finally... since you have an early boat... the MPEM control is relatively simple. It controls the kill and rev-limit by grounding the wire between the ignition coil, and the MAG coil behind the flywheel. SO... a quick way to eliminate where the problem is... is to disconnect that wire. On the Schematic, it says its Black/Red/Green. But I don't think it's a double trace. I'm guessing it's just Black with a red stripe.

SO... if you pull that wire off the MPEM... and you still have an issue... it's either the MAG or ignition coil. (And the MAG coil is easy to check) If the problem goes away... it's the MPEM.


Oh... that wire is your "Kill" wire. SO... you may want to hook up a long wire so you can actually shut off the engine as the key won't do it. Just touch it to a ground. but be careful... that's relatively high voltage when the engine is running. The other way to shut it down is to pull the choke. That's safer, but will make it hard to restart.

Thanks for the help!!

unfortunately it is now seemingly like the CDI portion of the MPEM is busted... which is giving me all sorts of sporatic issues, which I'm seeing as the fuel guage is periodically working.

Problem is, the mpem is 278000571 which is a super super rare part... honestly hard to find ANYWHERE and Bombardier doesn't even have one.

Any suggestions and maybe its just worth sending the mpem out to get a conversion??

 

[mikidymac]

I think @Minnetonka4me was offering conversions that use the PWC MPEM's for the boats.

 

[r3cc0s]

I think @Minnetonka4me was offering conversions that use the PWC MPEM's for the boats.

so I found a mechanic in town who has done the conversion and is converting this weird MPEM into a CDI, which is good to help me future proof this boat

The compression is low at 135/132 so its due for a rebuild, but I want it out in the water.

The funny thing left is an exhaust leak on the tuned pipe, which nobody... NOBODY can seem to source one of those brass rings that is then clamped between.

 

[mikidymac]

Compression is still ok but not perfect. Rebuild isn't necessary until about 120 psi.

Contact Westside Powersports Seadoo, I am sure he has the "Copper" ring for the pipe.

 

[r3cc0s]

Compression is still ok but not perfect. Rebuild isn't necessary until about 120 psi.

Contact Westside Powersports Seadoo, I am sure he has the "Copper" ring for the pipe.

seems like the specific part is 274000152

but this can't be the only boat/motor with the same sized ring on the tuned pipe... I'm sure other part #'s should work right?

I'll give them a call

 

[mikidymac]

That ring was only used on that pipe for your boat and the Seadoo HX PWC. It isn't that common and discontinued. Westside should have them.

 

[r3cc0s]

That ring was only used on that pipe for your boat and the Seadoo HX PWC. It isn't that common and discontinued. Westside should have them.

Thanks for the heads up and yes he only had a couple left and I managed to snag one. In the interim, my mechanic took the existing ring, flattened it, trimmed of anywhere it was bent (was bent when my old mechanic installed it) and put a bead of sealer in and so far its holding up.

So the "conversion" worked well, with the exception that the fuel gauge isn't reading, and I'm bringing the mechanic to look at it. (blower, bildge pump, lights all work)

No more beeping!

Only thing is... its not pissing again off the tow hook.... Sigh... this is like the 3rd time this happend.

Funny thing is, this time, the engine isn't getting hot, just slightly warm on the head and the manifold that I can leave my hand on easily.

I think my old mechanic, as he was reasealing the pump from replacing the coin oil, went a bit liberal with the silicone ...

any tricks again for this? last time I had to replace MOST of my hoses and exhaust system with the old mech. (I do have a flush attachement)

 

[r3cc0s]

Update: Wasn't able to bring it back to the same mechanic, but found the only other guy who is 4 minutes over from my place, who used to work with that mechanic.

The conversion is working well, but the fuel gauge isnt' reading... and there is proper resistance (reading) coming from the gas tank sending unit

In case, I found a used fuel gauge from ebay to see if this solves the problem.

Ends up the pisser got clogged only from the cylinder head to the pisser, so he has to pull the pipe and clean it out. Otherwise the engine/exhaust was in fact flushing just fine.

**Any good tricks on keeping this clean or preventing this from happening?

Also got the new scupper and the ring in.

I think I'll attempt the scupper, but I may just get my mechanic to do the tuned pipe ring, as my old old mechanic had busted the old one when he had installed it before.

 

[r3cc0s]

Update - took the boat out two times for a good couple days of bombing around and fishing

I installed the scupper but haven't installed the copper ring.

So far, I look and am not seeing any smoke or sweating coming from the tuned pipe where they are attached by the clamp and am not seeing any leaks.

That said... everything seems to be good and runs well, but "sometimes" it doesn't or take a long time to get into its powerband....

like it "bogs" when the motor has ran for a while, until it hits its powerband and then I can get on plane. Its fine when the motor has some rest time or is reasonably cool (like the first half an hour)

If I turn on the bildge fan, or open the rear hood, and fresh air gets in, it seems to be much more responsive...

is there a chance there is just not enough air, a leak OR is the compression just not enough on the motor that may be causing these symptoms?

 

[r3cc0s]

?

 

[mikidymac]

Exhaust leak.