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2014 Scarab215HO rough idle fixed - I think

John P Jones

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Year
2014
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HO Impulse
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2014 Scarab 215HO - Engines were not running well when I attempted the Spring opening. Changed the plugs, oil and filter, flush and fill of the antifreeze. Cranked up the engines - very rough. CanDoo Pro scanner showed multiple misfires on both engines. Pulled the plugs again and activated them with the scanner - I had 2 bad coil packs. Replaced them and checked the spark out again - good spark (though something funky with the starboard engine cylinder #2 - will talk that soon). With spark - and plugs put back in - still running very rough. I pulled the fuel rail - found out that activating the fuel injectors via the CanDoo Pro doesn't exactly work - so I hung little bottles off the injectors and cranked the engines. I got spray, but it looked horrible. Removed the injectors and cleaned them using a DIY method I found on YouTube. Worked great. Port engine - runs fantastic now - no more faults - everything is cleared. Starboard engine is running a whole lot better - sounds like the port engine - but the CanDoo is still picking up a misfire on cylinder #2 - even though no check engine light and it's running smoother.
Now for the goofy stuff - and I hope someone can help with this:
When I initially activated the plugs via the CanDoo scanner, cylinder#2 would fire, then I'd hear a high pitch squeal (electrical, not mechanical) and the CanDoo scanner would lock up - I'd have to close out the software and reopen it. This happened consistently with Starboard cylinder#2 ONLY. But still no check engine light.
Any ideas on WHY cylinder 2 on starboard engine would do this?
 

Winerocks

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Often funny things like this are due to bad engine ground(s). I suggest taking some time and checking the condition of the ground cables on your starboard engine. If there isn’t a good ground, your spark plugs won’t spark properly and your coils will not be very happy.
 
Last edited:

John P Jones

Jet Boat Addict
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2014
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HO Impulse
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Often funny things like this are due to bad engine ground(s). I suggest taking some time and checking the condition of the ground cables on your starboard engine. If there isn’t a good ground, your spark plugs won’t spark properly and your coils will not be very unhappy.
Thanks, I'll take a look. Hoping its something simple like that.
 

John P Jones

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Swapped plugs, swapped coils, the problem follows the cylinder - I even swapped the fuel injectors.
The issue stays with that one cylinder.
What worries me - the spark comes directly from the ECM. Wiring diagram shows the coils going right to the ECM.
Gonna try swapping the ECM's tomorrow. If it moves from port engine to starboard engine, I won't be happy, but will need to find a replacement ECM for my 2014 Scarab215. Does anyone know where I would be able to find one? Finding parts these days has been nothing short of completely frustrating.
 

Winerocks

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From what I can see the ECM is the same as for Seadoo. It is a BRP part; not Scarab.
 

John P Jones

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Interesting. Would you happen to know where to get one?
 

Winerocks

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Interesting. Would you happen to know where to get one?
Looks like Torx Racing has stock ECU’s. Should be able to order from a Seadoo dealership or service shop. Somewhere on this forum is a link to the BRP website that identifies part numbers based on your HIN. Might be able to get it on Amazon.
 

John P Jones

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Update - I checked out the one cylinder that was misfiring again - pulled the fuel injector and ran it through a clean cycle, again. After which, I thought it was a little leaky. Put it back in for a trial run - came up as misfire again. I went to a shop that deals with Rotax motors for land machines and got an exact replacement. Whalah, the cylinder is no longer misfiring. I thought I was finally in the clear - BUT - now cylinder 1 is flagging as misfiring.
:( I give up...
Wondering if some of this is rogue flagging - a false positive. The check engine light no longer comes on and things sound really good no.
I think I'm gonna put it in the water and give it an in-water test run.
Since cylinder 2 is no longer flagging, I'm thinking I dodged the bullet of swapping out the ECM.

Any ideas as to why things seem to shift from one cylinder to another? A cylinder that wasn't flagging before?
 
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