650 Mercury "No Spark"

[sal850]

Hi,

I have a 650 mercury ob 73'.... hasn't been started in over 2yrs ... comp checked out @ 125 in all 3 cyl's. but I've got no spark at all! So I have a book on it Selco for that yr & hp but it saids it has "points" I called an outboard dealer they tell me it has a electronic Ign. Ser#3662309 Now I also notice running across the front of the starter their is what appears to be a condencer looking thing wired to the wht/blk on the switch box that has bear wire. He tells me that a safety switch and if I disconnect it I should get spark, but to no avail. Can someone help me out here with a step by step process in tracking down the problem. Thx

 

[jimpnl]

Re: 650 Mercury "No Spark"

It sounds like you have bad coils, I do not know how to check if they are but I do know if you take the Pull start top off, the coils are under that section. I have a 73 mercury 7.5 and that is where mine are. Hopefully this helps some, sorry I can not give anymore details, your book should be able to tell you more. I would search on the site for problem solving coils for 650 merc as a starting point. You can also go on youtube and search. I know it sounds crazy but that is where I saw a video on how to change out my water pump.

 

[crappiejig]

Re: 650 Mercury "No Spark"

Disregard the previous post regarding the coil info,it is incorrect.See this troubleshooting guide from rapair,for your specific motor(had one myself).
http://www.cdielectronics.com/downloads/troubleshooting guide/Mercury 3 Cylinder - 332-4796.pdf
You will need a dva meter for some of the checks,I have a spare switchbox if it comes to that,PM me next week if you need it. Scott

 

[sal850]

Re: 650 Mercury "No Spark"

Thanks for the direction Scott. I'll try it next week.