OMC Ignition Points

[RC]

Motor is 1986 OMC 4.3l.

In the 7 years I've had this boat it has always run like a champ. Only one other time was it running rough and a change of plugs fixed that. Last time out boat was running really rough. Figured it was time for a bit of a tune up. Replaced the plugs, wires, points, rotor, condensor. I ordered the tune up kit from iboats for the points. When finished boat wouldn't start. Did everything but turnover. After trying a few things that didn't work, I decided to put the old points back in. (at least 7 years old!) Engine fired right up. I didn't realize that wrong points would make a difference between starting and not starting. After seeing the old points I really want to replace them but not sure where to go.

Thoughts?

 

[boatguya1]

Re: OMC Ignition Points

Are the new points Physically the same as the old? If so make sure that nothing that should not be grounded is when you have the new points installed. You are setting the dwell/gap aren't you? The points are basically just a switch to ground that opens and closes for the wire from the coil. You must check/reset the timeing when you install/adjust points.

Some points have a seperate spring piece that must be installed to give them the tension against the shaft they need.

James

 

[Gary H NC]

Re: OMC Ignition Points

Napa Auto parts...Part number 18-5303
Thats if you have the Prestolite distributer..(should be)

Take the old points with you...

 

[Fishermark]

Re: OMC Ignition Points

Some points have a seperate spring piece that must be installed to give them the tension against the shaft they need.

That's where I would put my money - check to make sure you didn't leave the spring out. (Don't think of a spiral spring, it is simply a piece of spring steel). Here's a pic:

 

[RC]

Re: OMC Ignition Points

The new points did look just like that picture and yes I made sure that separate piece was in properly. The points did look physically the same and I adjusted the gap according to my manual. I do have issues adjusting the timing due to the marks no longer visible, i've been using a dwell meter to help with that. How can I figure out what type of distributor I have. There don't appear to be any names or numbers on it that I can see.

Thanks for the help so far.

 

[boatguya1]

Re: OMC Ignition Points

As far as I know there is no way to check the timing with a dwell meter. Adjusting the dwell is a more precise way to adjust the gap on the points.

Changing the dwell/gap will change the timing.

James

 

[Gary H NC]

Re: OMC Ignition Points

If it has the screw down cap (2 screws) then its a Prestolite...
My other boat was a 86 Cobra 4.3,Original Prestolite Dist...

 

[MikDee]

Re: OMC Ignition Points

This reminds me of the time about 10yrs ago, when a guy I knew (not too mechanical) at the marina was trying to do a tune up on his OMC engine. He had just put new points in, and it was running like carp! The marina mechanics, who weren't all that good, had given up, & walked away. He asked me for help, and I walked over, and asked what was wrong? He mentioned what he did, and then held up the little copper spring strip, and said "What's This?" and "Where does it go?" I hopped into the boat, explained how it works, (increasing spring pressure on the points) and put it in for him, he started the boat back up, and then it ran great. He was quite thankful, and relieved, I was glad that I could help, but amazed at the fact that the marina mechanics didn't have a clue