Mystery engine. Pics attached. no spark

[5thcorps]

Hello everybody. My first post. I am a 20 year dodge jeep mechanic and electrical specialist who was tasked with getting this boat engine running. My problem is I don't know exactly what it is.

There are what I believe to be mercury logos on various small parts like freeze plugs but all signs point to it being a Johnson from what a friend has told me. Any thoughts? It has no spark. If I could figure out what the engine is then possibly someone could point me to where I could find the manual for diagnosing the electronics. It is a v4 I'm pretty sure and big enough to be around 100hp I'm thinking. Any help in identifying and finding the manual on this thing is GREATLY appreciated.

 

[racerone]

It is a JOHNSON of 110 /115 hp rating.-----Late 1980's model is my guess.-----The M you see is the OMC logo.---Nothing to do with Mercury motors at all.---------Post picture of the cowling if it is original graphics.

 

[5thcorps]

Cowling has been completely stripped and repainted. no markings left

 

[5thcorps]

Any idea where a service manual or electrical diagnostic info could be found?

 

[5thcorps]

were these 2 or 4 stroke?

 

[racerone]

Do you see a timing belt anywhere ?-----------------No these are a 2 stroke motor.--------Originally came with oil injection.---------It is up to you to determine if oil injection is still in service.---------Many were bypassed in favour of 50:1 premix.---------Running that motor on straight gas will be expensive !

 

[jbcurt00]

were these 2stroke

Yep

 

[5thcorps]

Do you see a timing belt anywhere ?-----------------No these are a 2 stroke motor.-

I have never worked on an outboard motor in my life. I never assume anything that I've never touched

 

[Vic.S]

Any idea where a service manual or electrical diagnostic info could be found?

OEM manual should be available from Ken Cook Co.at https://www.outboardbooks.com/index.cfm but you need to ID it first. No ID plate on the transom clamp bracket ?
The model number may be on a welch plug on the powerhead somewhere.

I think it will be covered by one of the ( Seloc) manuals at http://boatinfo.no/lib/library.html

See also the troubleshooting guide on the CDI electronics website http://www.cdielectronics.com/support/

Also much useful info on the Engine FAQs board http://forums.iboats.com/forum/engine-repair-and-maintenance/engine-frequently-asked-questions-faq