Vintage 9.5: Can you set points with a timing light?

[guy48065]

I haven't been able to find a clear answer to this question. Almost all webpages, YouTubes and forum posts just show how to set point gap to spec but I've found a couple that mention using a timing light & the timing marks on the flywheel to verify or fine-tune each point adjustment. None have shown how.

As a young man my first couple cars had point ignition. You could get the engine running by setting the gap to spec but if you wanted GOOD performance you needed a timing light. On these small outboards there's no adjustable distributor--the only way to adjust timing is by adjusting point gap.
What's the procedure?

 

[Chris1956]

You can use an ohmmeter to set the points. You want them to open at the same time relatively to each other.
I do not know if a timing light would be an improvement, on those magneto systems..

 

[brodmann]

Timing light is not used for adjusting points. Feeler gauge is the only tool needed to adjust points. Clean them up good with emery board or fine sandpaper and set the gap. Not rocket science. A timing light is used to make sure the points are opening "firing" at the optimal point in the rotation/piston location of the motor. Link and sync is the most important procedure to get the most out of your motor. Set the point gap, and follow procedures in the manual for your motor to make sure the carburetor/carburetors (if you have more than one) are opening at the right time and that the ignition timing is according to specifications.

 

[kbait]

Timing fixture and continuity tester will get you spot-on. .020 at widest gap will be very close to right-on. Make sure armature plate has no lateral play as it makes for erratic point opening timing.. good luck!

 

[Crosbyman]

 

[guy48065]

There are timing marks on the flywheel that are useless for adjusting the points, which are hidden underneath. Why are these marks there if there's no way to adjust timing?

(I'm being devil's advocate here--the point gap DOES affect timing)

Is it more important that the points be set to some number .020, .019, whatever... Or that the spark occurs at the correct point in the piston travel?

 

[Crosbyman]

don't make it more complicated.... Remove the FW and just set points at .020 on the hight point of the cam lobe or get the pointy tool ..works great

just... openning at the mark is more critical than the gap itself

 

[Chris1956]

Remember, the spark plugs fire just as the points open. You want them to open, just as the timing marks align.

Some motors have a "window" in the flywheel, allowing point adjustment with flywheel on. If you do not have such a window, pull the flywheel, set the points with a feeler gauge and then temporarily install the flywheel, without tightening the nut and use the ohmmeter and timing marks to detect when the points open.

 

[racerone]

Those timing marks are NOT USELESS at all.----Just need to take a few minutes to learn how to do this elegantly simple work.

 

[guy48065]

Those timing marks are NOT USELESS at all.----Just need to take a few minutes to learn how to do this elegantly simple work.

Can I assume from your handle that you might be a little more interested in peak performance, rather than "set it & forget it"?
There's no way feeler gauges are going to get you closer than +/- 5° of rotation. Hell that TOP spot on the points cam alone is about 10° wide.

The problem is I can't find any clear info in order to "learn how". I've only run across a couple YouTubes that hint that it's very useful to know that ACTUAL ignition point.
But I certainly understand that most people don't want to go to the trouble of removing the flywheel over & over in a "trial & error" approach to nailing the timing.

Or is there a way to do it without the repetition and trial & error?

 

[racerone]

You can use a timing fixture.----Timing fixture is a dummy flywheel.-----In fact you set the flywheel in place with timing mark between the lines.----Lift flywheel off and set point to OPEN with a meter.----Repeat for other set of points.----Job is done.

 

[Crosbyman]

"Give us the tools and we will do the job" ...Winston Churchill.

get yourself the timing fixture or use the video method and you will be 100% accurate till the points and rub block wear down.

 

[guy48065]

You can use a timing fixture.----Timing fixture is a dummy flywheel.-----In fact you set the flywheel in place with timing mark between the lines.----Lift flywheel off and set point to OPEN with a meter.----Repeat for other set of points.----Job is done.

So the "pointy tool method" to gap the points.
I agree that will get you the best mechanical approximation of correct timing.
I guess if one wants to fine-tune from there the only choice is trial & error.
Now I have a better understanding why nobody bothers to go beyond approximate timing.

 

[racerone]

I started using those timing fixtures over 50 years ago as a teenager !!----It is simple.----Today I find it just as easy to use the actual flywheel to set the points accurately !-----And you can use a timing light pointed at those 2 vertical lines to check your work.

 

[Crosbyman]

So the "pointy tool method" to gap the points.
I agree that will get you the best mechanical approximation of correct timing.
I guess if one wants to fine-tune from there the only choice is trial & error.
Now I have a better understanding why nobody bothers to go beyond approximate timing.

why do you refer to the timing fixture as only able to provide approximate timing when it will do exactly what a timing light will do which is to fire the plug dead center between the timing marks. are we splitting hairs ??

 

[OptsyEagle]

I have used the multimeter method of determining proper timing, many times, where I find the exact moment the point opens, and then align the flywheel and confirm the timing marks are good. When I am done I will also check the point gap. In every single instance the point gap was at the 0.020" mark when my points were set correctly. Now I don't waste my time. I set the points at 0.020" and it is done.

 

[guy48065]

... are we splitting hairs ??

A little.
I'm a metrologist by trade. Calibrations. Accurate measurements using first principles is what I do every day. The point gap sets your ignition timing but it's a very crude process and the way most people do it doesn't involve the timing marks at all. That's what I meant by "approximation". The "pointy tool" improves it greatly by referencing the point opening directly to the timing marks. You can do the same with the flywheel attached by running a wire from the points screw thru the bottom of the plate & out to a continuity light or meter--but then you can't adjust the points unless you have a year/version with access holes in the FW.

A timing light can tell you directly and precisely when the spark fires, referenced to the timing marks, without special jigs or running wires. But there's still no way to conveniently adjust the points without removing the flywheel...probably numerous times as you sneak up on the final setting.

I was hoping I was missing a shortcut to get to the end goal.

 

[racerone]

You are overthinking !----In my opinion it is elegantly simple using the flywheel.----Line up the marks.----Lift off the flywheel.----Set points to open with meter.----Repeat for the second cylinder.----Job is done !!----Accurate and simple.

 

[Crosbyman]

millions of these outbards get timed this way... .020 widest gap at the high point of the lobe.... or using a buzzer, modified flashlight light bulb, a piezo buzzer whatever incl .a VOM !

your motor magneto falls in this categoty.. just time it has instructed numerous times and go fishing,.

 

[Yellercat]

I haven't been able to find a clear answer to this question. Almost all webpages, YouTubes and forum posts just show how to set point gap to spec but I've found a couple that mention using a timing light & the timing marks on the flywheel to verify or fine-tune each point adjustment. None have shown how.

As a young man my first couple cars had point ignition. You could get the engine running by setting the gap to spec but if you wanted GOOD performance you needed a timing light. On these small outboards there's no adjustable distributor--the only way to adjust timing is by adjusting point gap.
What's the procedure?

Nope