No Spark?!?

[aspaziani]

Hey guys heres the background, last year i took a pretty hard fall after jumping a wake and ended up having to replace my drive shaft and pto flywheel since they were striped out. i just got it all back together (finally) and now i have no spark. Everything worked fine when it left the water but after changing the shaft and pto i have nothing. i have 26K resistance at the plugs with caps on, and im getting power to the coil, tested by removing white wire and cranking. Battery and plugs are brand new, so any suggestions?

PS. Could this have anything to do with the position of the magneto? I had turned the engine manually while removing the flywheel but im not sure if they need to be aligned in anyway?

More info after testing:
i get about .13V between white wire from coil and ground when ski is off and it drops to about .2 when cranking (meter set to 20V)

took off white wire and tried for spark..nothing..so i think that means mpem is good?

 

[Dr Honda]

Hi,

well... the 97 is kind of strange. I was trying to get an answer from a guy a few days ago about his coil. On some of the 720 engine ski's... the CDI is built into the coil, and the MPEM grounds it to kill the engine, and to control top RPM's. BUT... on your ski... I think you have a regular coil, and the CDI is built into the MPEM.

But do this... open your rear electrical box, and look at the coil. Please let me know if it says CDI on it's label.

 

[aspaziani]

Thank you for the response!

the coil does not say "CDI" the part# is 278001130. it seems to me that its either a coil issue or a timing issue. Im leaning more towards timing since i recently replaced the shaft and before that everything worked fine. What i don't know is if the shaft position is off would that cause no spark at all? According to the manual in order to fix the timing i would need to get the tool to measure the piston position and adjust the magneto position accordingly. Like i said i tested the coil as best i could but if you have any other tests i can perform please let me know. Thank you.

 

[brandon32689]

What kinda ski is it? Can't see your Sig or anything since I'm on my phone but did you notice if your trigger looked good. Mines went out in both my 96xp.

 

[aspaziani]

i have the front cover off but i cant really get a good look at the trigger because of the angle, and i didn't want to unscrew it from the housing since i wasn't sure how critical the position was, although the book says its not adjustable. Is there a way to test it with the multimeter? My ski is a 1997 GSI with the 718 engine. Thanks

 

[Dr Honda]

You don't have a "Trigger" coil. You have an HV generator coil that feeds a reverse pulse CDI system. On most of the 720's... the CDI is built into the coil, but yours is built into the MPEM.

Why do you think it's a "timing" issue? If there is no spark... the problem is somewhere else. Check the resistance in the HV coil... and the resistance across the ignition coil. If both of them check out... your MPEM may have gone bad.

 

[aspaziani]

I was only going off what the manual says, it states that the trigger coil makes continuity with the magneto and then sends the "fire" signal to the coil, if i understand correctly, and this i believe is a small round attachment on the outside of the front cover to the engine, which has a 4 prong connector with yel, yel-blk, blk, and blk-red wires. Does the HV coil do the same thing? and how would i test the ohms on that? i did test the ohms on the ignition coil, i have 26K at the wires with caps on and i have about 1.1 across the top terminals where the black and white wires connect to the spade connectors. I only thought timing was an issue because it worked when i brought it out last season and the shaft is the only thing i changed, but i didn't know if that would cause no spark at all, i would assume it would just run rough since the timing was off but would still spark, but i wasn't sure.

So if you could let me know how to test the HV coil ill be glad to report back, and let me know if you think the readings on my ignition coil are good, i think the wire readings are but i'm not sure on the posts.

Thank you
(sorry that's so long)

 

[Dr Honda]

The 800 engine has a trigger coil, your engine does not. Trigger coils, or Hall effect devices are used on DC-CDI units. You have an HV-CDI.

Just check across the blk-blk/red wires, and you should be seeing 0.05 to 0.6 Ohms. (the yellow wires are the charging coils)

 

[aspaziani]

Ok i just tested the HV coil and got nothing between the black and black-red terminals. so could this be a sensor or magneto issue? and do you know of a way to test either part? perhaps if i get a reading from the yellow charging wires that would indicate the magnetos are generating current and still good?

 

[Dr Honda]

You need to pull the flywheel from the engine. It sounds like your HV coil is bad. That normally means physical damage.

 

[aspaziani]

OK i will pull the flywheel this weekend, maybe this was caused when i screwed the tool into the front of the engine to keep it from turning while i unthreaded the PTO flywheel to replace it. But the bolts i used where only 1.5" at max and i only threaded them in .25" to .5". But i will see if they scraped against anything when i pull it. Thank you for your help.