No Spark - 90 Merc Sport Jet

[silly34]

I've read and read and read posts trying to wrap my head around this and honestly the answers are there but I'm aggravated and am just missing it. I think I have the new stator, what I see is red underneath the flywheel cover but I haven't taken the cover off yet.

I was going to test some wires tonight but it has gotten late and started storming. I was able to unplug the yellow/black wire from switch box and still no spark. Mind you I've taken the top plug out with it connected (and grounded) and turned the motor over.. no spark that I could see. I also unplugged 2 yellow wires from voltage regulator and no spark.

I've read posts about the ignition switch could be bad but I dunno. I should point out that I had to replace the starter the other day as it burned out after trying to start this thing. No prolonged starts just numerous attempted starts.

Attached are pictures for everyones viewing pleasure. They are not of the greatest quality..again dark out with hurricane winds blowing.

Figures this would happen when I have a buyer wanting to come look at it in the morning....

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

"red stator has green/white and white/green wires running to a rectifier"

Yup... I have this. Hope it isn't dead though.

B.

 

[aksor]

Re: No Spark - 90 Merc Sport Jet

It could be a number of things just went trough this myself. My first issue was a loose flywheel magnet I JB welded it back it run for 50 minutes in the water before my trigger assembly failed, replaced trigger it still no spark, scraped the black gunk out of the CDI (black box with lots of wires) very carefully not to damage the board to find that the trigger took out the semiconductor switches SCR's, it now works. I've got so desperate to get it going after being ripped off by an internet ahole for $272 for a new cdi (It's in Paypals hands now).

I noticed that you have the old voltage regulator and the clear epoxy looks dark I bet you that it's burned, this can also destroy your stator. The reason for it going bad is because the red stator is an upgrade and it provides 16 amp max charge to the battery instead of 9 amp. Whenever red stator replacement is made the voltage regulator should be replaced with a 16 amp unit.

first thing check the magnets under the flywheel for loose or broken magnets (common). if you find a broken magnet you will need to find someone on the forum who has some spares (venxxxx) or time to buy flywheel. Broken magnets cannot be reused!!! they become two magnets once broken.

you also need to do some measurements:

get an ohm meter and measure the resistance between the green/white and white/green wires it should be between 600 to 700 ohms it depends on ambient temp, if it checks out then measure the resistance from the trigger common white/black to brown, white/black to white, white/black to purple it should be between 800-1200 ohms.

If that checks out check to make sure you get no voltage on the black/yellow wire in any ignition switch position by measuring for voltage between engine ground and the black/yellow wire while you have someone turn the key to different positions.

Any voltage on the kill wire will destroy your CDI module

BTW I sure hope you have a garden hose hookup made for it if starting it in the driveway or u will cause more damage to your ride plate

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

I noticed that you have the old voltage regulator and the clear epoxy looks dark I bet you that it's burned, this can also destroy your stator. The reason for it going bad is because the red stator is an upgrade and it provides 16 amp max charge to the battery instead of 9 amp. Whenever red stator replacement is made the voltage regulator should be replaced with a 16 amp unit.

Ok, thanks! Now to find one affordable.

first thing check the magnets under the flywheel for loose or broken magnets (common). if you find a broken magnet you will need to find someone on the forum who has some spares (venxxxx) or time to buy flywheel. Broken magnets cannot be reused!!! they become two magnets once broken.

Haven't had a chance to do this just yet..today.. will shortly


you also need to do some measurements:

get an ohm meter and measure the resistance between the green/white and white/green wires it should be between 600 to 700 ohms it depends on ambient temp,


And I got a reading of 685, on to the next test once rain stops......

more characters per forum before it will let me post this.....

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

measure the resistance from the trigger common white/black to brown, white/black to white, white/black to purple it should be between 800-1200 ohms.

Ok my wires aren't the same color. I have a white/black from switch box to a brown/black, then a white from switch box to brown, i have a purplish maybe pink looking wire from switch box connecting to maybe a black wire or dark gray. I tried connecting the meter to them but don't get any readings

If that checks out check to make sure you get no voltage on the black/yellow wire in any ignition switch position by measuring for voltage between engine ground and the black/yellow wire while you have someone turn the key to different positions.

No voltage indicated

maybe this pic will help, oh and I have a candy bar looking thing too that has a blue wire and white/green, green/white wires out of it..

 

[emoney]

Re: No Spark - 90 Merc Sport Jet

I'm not the guy that even should be weighing in, but.......Have you checked the kill switch to make sure there's not an issue there 1st?

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

If that is the yellow/black wire..then yes and it doesn't show any voltage.

B.

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

I'll be yanking the flywheel cover off once it stops raining... hopefully I can find those wires for the trigger

B.

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

Ok guys.. got the flywheel cover off and had to laugh at myself. The wires are the correct color they just had a bit of grim and discoloration. My meter only has a setting for 2k OHMS so this is what it showed..

Purple: 1.280
Brown: 1.289
White: 1.278

think the range was 800-1200, am I too far off that mark?

B.

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

Oh, found a related thread (kend301) to the OHMS being 800-1400 for trigger.

B.

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

Wifey is bringing home a puller...rented it from the parts store. YaY for the wife! Will have magnets checked tonight. If that checks out then I reckon I need a switch box or is there anything else I can test?

B.

 

[aksor]

Re: No Spark - 90 Merc Sport Jet

Did you check the coils?

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

How? Learning as I'm going. Magnets are OK. Ordered the proper regulator and a switch box tonight.

B.

 

[aksor]

Re: No Spark - 90 Merc Sport Jet

Here is a link to the manual on ignition testing and timing, http://motorka.org/doc/mercury/service_manual/jet/SJ90_120_95xr_125xr_831996r1/sec2a.pdf i f the link dont work pm me.

 

[silly34]

Re: No Spark - 90 Merc Sport Jet

Ok guys.. new switch box and rectifier... and all is GOOD!! Every turn of the key and she fires right up. Anyone interested in buying a boat?

B.

 

[aksor]

Re: No Spark - 90 Merc Sport Jet

At least use it for the summer then sell it in the spring