Timing question ... a dumb one

[Dave Irish]

Why is my rotor ending up at 6 o clock after I trip the mag during the timing process?

[Glen]

Hi,
The first few years of Cub operator's manuals tell how to time the magneto to the engine.
About the 1st thing is to turn the engine to number 1 cylinder TDC. Did you do that.
Below is a pic of how the magneto drive should be turned when the engine is at number 1 TDC.

[Dave Irish]

Yes, I had just replaced the points and installed the rotor. Install the mag. And when I turn the motor two turns back to tdc and pull the mag away from the engine to trip it the rotor is bass akwards ....

[Glen]

Did you align the timing marks on the rotor and it's drive gear, and grease the gears, below is a pic of the marks.

[Dave Irish]

Yes I was in there a couple times to day

[Glen]

Below is a page from the 1949 Cub operator's manual telling how to time the magneto to the engine.
If the timing gears in the engine are assembled right, so the drive is in the right position, you may be making a mistake somewhere.

http://farmallcub.com/rudi_cub/www.clea ... age-32.jpg

Paragraph 5 says to turn the engine 1 full turn, after putting the magneto on the engine.

You didn't say if you tried to see if the engine runs.

I haven't had a magneto lately, maybe one of the magneto experts will comment.

[Bill V in Md]

Have you checked to make sure the timings marks line up on both the governor gear and the idler gear line up?

[Jim Becker]

Depending on the exact procedure you use, the rotor ending up at 6/7 o'clock may be correct.

[Eugene]

Depending on the exact procedure you use, the rotor ending up at 6/7 o'clock may be correct.

Yup. Could be the #4 cylinder is on the compression stroke -- tractor will start and run just fine. Cylinders #1 and #4 are on/have opposite strokes, either compression or exhaust, when the mark reaches the pointer.

Dang, I said that I wasn't going to post any more this month.

[Dave Irish]

Update . She is timed I have replaced everything from the points to the plugs, adjusted valves.. I spray carb cleaning up the intake manifold and still no fire?

[Glen]

Hi,
You could test the spark, and see if it has a good spark.
The spark should be blue, and jump about 1/4", from a spark plug wire end, to a bare place on the engine.
A yellow spark is weak, and needs improving. People on here have said the engine may not run with a yellow spark.

There is an insulation in the side of the magneto, at the post on the side of it. If it is cracked, it can short, and the engine won't run.
Tightening the nut at the end of the point spring too much can break the insulation, especially if it is the original from years ago.

TM Tractor has a new insulation, below is their listing, you can look at the pics.

http://www.tmtractor.com/new/el/957fp.htm

Just trying to give you suggestions as to what could be wrong with it.
If you replaced the condenser, and there is no spark, the new condenser could be defective.
Put the old condenser in and try it, if it worked before.

Some points may have a clear coating on the surfaces, it keeps power from going through them, and needs to be removed so the engine will run.
I'm not sure if any Cub points now have that, I think someone in the past on here said points he put in his Cub had it, and he had to remove the coating.