1975 OMC 140hp 4 cylinder engine no spark !!! Won't Start

[dave33222]

Ok so here the deal I have a ignition problem. I have a nice blue spark off the coil lead wire to the cap but no spark off first spark plug when I pulled it. So I figured its probably a bad cap or rotor so I replaced those along with the plugs and new wires. After that still no spark off first plug. What else could it be? Is it something to do with the points under the cap? Any help would be appreciated, thanks.

 

[Bondo]

Re: 1975 OMC 140hp 4 cylinder engine no spark !!! Won't Start

Is it something to do with the points under the cap?

Ayuh,... Most likely, Yes...
Do they get power,..??
Did you set the gap,..??
Are they Shiney clean,..??
How's the Dwell,..??

 

[Don S]

Re: 1975 OMC 140hp 4 cylinder engine no spark !!! Won't Start

Check the bushings on the distributor shaft. Side to side, and probably only in one spot. Too much movement and the points won't open and close.

 

[dave33222]

Re: 1975 OMC 140hp 4 cylinder engine no spark !!! Won't Start

They are getting power because when they close when i turn the rotor by hand they spark some. but when i set the gap and crank the engine they open and close really fast and there is no spark when the points close.

Im so lost there is spark coming off the coil lead wire and into the cap. the cap and rotor plugs and wire are all new. But there is no spark at the first plug. What could it be?

 

[superbenk]

Re: 1975 OMC 140hp 4 cylinder engine no spark !!! Won't Start

Had that problem early on as well. Replaced points & condenser and it fixed the problem. Seems that's a simple next step that's not very expensive.