1988 90hp no spark.

[AEROCOOK]

Hi all.
Im helping a friend fix up a boat with a 1988 Merc 90hp 3 cyl motor that has been in storage for 2 years. The motor was properly winterized by a marina in the fall of 2008 and was in good working order at that time but now there is no spark. We have checked for obvious things like disconnected wires and made sure the lanyard switch was in the proper position but it still has no spark. Im wondering if you folks have any ideas or advice on troubleshooting?

 

[Faztbullet]

Re: 1988 90hp no spark.

Sounds like the stator has took a dump which is common on the 87-89 year models. Download the CDI troubleshooting manual and check your ignition system....

 

[AEROCOOK]

Re: 1988 90hp no spark.

Sounds like the stator has took a dump which is common on the 87-89 year models. Download the CDI troubleshooting manual and check your ignition system....

Could the stator fail while in storage? As mentioned, the motor was running well when it was put into storage.
Also, where can I download the CDI troubleshooting manual from?

 

[Faztbullet]

Re: 1988 90hp no spark.

Yes and link below:


http://www.cdielectronics.com/downloads/troubleshooting guide/Mercury 3 Cylinder.pdf

 

[AEROCOOK]

Re: 1988 90hp no spark.

Thanks for the link Faztbullet. I started at the top of the diagnostic sheet in the "No spark on any cylinder" section and quickly determined that the stop circuit was not at fault, I then tested the rectifier and determined that it was good. I know that the engine was cranking fast enough to provide a good spark, so the cranking RPMs could not be the problem either. All electrical connections were tight and clean so I ruled out that and moved on to step 5 and thats where I found a potential problem... The motor has a black stator and glued in magnets on the flywheel and when I checked resistance between the blue wire and ground I got a reading of 570, spec is 500 to 600 so that was good but when I checked the red wire I got a reading of 111 when spec is 28 to 32. I'm not an electronics wizard by any means, so I dont quite know how to interpret the numbers. Does that reading of 111 ohms mean that the stator is shot?