1966 18 hp Fastwin - Points Adjustment

[Grantspec]

Ok, so I know this topic has been covered a hundred times over. But I have a question that I have not seen answered.

I adjusted my points via this instruction. - 3 HP Evinrude Lightwin Ignition System Tune-Up 1952-1967

I adjusted so the points opened when the mark on the flywheel is directly in between the two lines on the magneto plate as the instruction suggests. When I checked the points with the feeler gauge after adjusting they had a way larger gap then .020, probably .040 or so.

Also, when I check with a timing light the mark on the flywheel is falling right in between the two marks.

The points are brand new as well.

Everything I have read has indicated that the gap should be .020". Any thoughts? It seems to me that the large gap would effect the dwell time. But I am confused because the timing seems ok and the engine seems to be running ok (after I got the float installed right side up :facepalm.

 

[kbait]

Re: 1966 18 hp Fastwin - Points Adjustment

If you checked w/timing light, then points are opening exactly when they should.. .02 point gap will work, but you have fine-tuned from there by setting to pointset opening, so point gap is bound to be different. Don't know if .04 would be a normal difference.. but if they're both firing at the right time, it must be correct.

 

[cajuncook1]

Re: 1966 18 hp Fastwin - Points Adjustment

When you use a feeler gauge to set timing with the points the manual and the flywheel state to set them at 0.020 inches. With this method you will get the motor's ignition time pretty darn close and the engine will run fine. When you use a timing fixture or the flywheel's marking along with the ignition plate timing marker, you are using a precise method of timing. When you use this method it sets the points to open at the right time to allow the voltage from the coil's secondary windings to travel to the spark plugs and fire just at point where the piston reaches TDC. This allows for exact 180 degree firing, so you get much better idling and running.

When using the timing fixture and the marker on the mag plate or flywheel marker and mag plate marker the measuring of the gap is off the table. The distance of the gap is irrelevant, because it is the exact time the points have no continuity(not touching) that allow for more precise timing and better spark.


Here is a video of using a timing fixture to set timing instead of the feeler gauge. (There is nothing wrong with using the feeler gauge method, because it works just fine.)

Please click on the you tube link below.


Setting ignition timing with a timing fixture on Evinrude, Gale and Johnson motors - YouTube


Cheers!!

David T.

 

[Grantspec]

Re: 1966 18 hp Fastwin - Points Adjustment

I had just read that the correct timing should be within .005" of the .020" setting.

.040" just seems so far out of tolerance. But I guess the timing light doesn't lie.

 

[racerone]

Re: 1966 18 hp Fastwin - Points Adjustment

You said ---" probably 0.040" or so " ----What is the actual measurement ???-------The coils are firing at the correct time.-------This dwell time is more important on a 12 volt system and not so much on this magneto.

 

[Grantspec]

Re: 1966 18 hp Fastwin - Points Adjustment

I'll double check the actual gap with my feeler guage this evening. I need one of those nifty timing fixtures so I don't have to take the flywheel on and off!

Also, cajuncook1, thank you for making the videos! Your carb rebuild video was how I found my float to be upside down.