Farmall Cub

I'm pretty sure that I put everything back correctly. Lined up the punch mark with the needle on the front. Looked in the spark plug hole to verify TDC. Adjusted the distributor for the electronic ignition to line up #1 with the rotor. She fires up quick and runs all the way through the RPM band very well.

But I can't get enough power to run the PTO and the C-2 belly mower. Would the engine run at all if #1 was sparking with the exhaust/intake valve is open?

I think my problem may lie elsewhere, but timing is so easy to adjust. And I can't get a good reading with my timing light. It isn't even close at 0 degrees, but flip the light down to 180 degrees and it reads almost perfect with the dimple mark. The light did tell me my engine was getting to 1800 RPM.

I'm going to check the valve lash this week. I doubt they've ever been adjusted. Anybody else know of any places that I could be losing power? I've been reading these timing threads with interest, but I may be barking up the wrong tree.

I've also checked the mower. Everything spins free and quiet. I also did a compression test during re-assembly. Readings were from 105 to 120 psi wet.

If you were 180 off the tractor would not run. I won't get into electronic ignition because everyone knows my opinion.

180 degrees off would indicate that you are taking the timing light reading off of either #3 or #2 spark plug cable.
Engine runs, lack of power, timing light 180 degrees off, ='s, two of the spark plug cables are attached to the wrong plug.

Cecil wrote: I won't get into electronic ignition because everyone knows my opinion.

Not me. I'd be interested in your opinion. My apologies in advance if this is a can of worms.

How's it sound?

If it sounds like a Harley Davidson or old JD 2-cylinder, you have two wires crossed.

If it sounds like a sewing machine, you're hitting on all four.

Definitely a sewing machine. I would be taking more drastic measures than "adjustments" if she didn't sound so good.

Maybe I'll try and get a video tomorrow.

And I definitely had the light on #1 wire. I checked that about 5 times because I was repeatedly convinced that I must have the wrong wire.

Since you state that you are positive you are taking the reading off the spark plug cable leading to the number 1 cylinder. And then, if your initial description of the timing light indications being 180 degrees off and the tractor still runs then.

Eugene wrote:180 degrees off would indicate that you are taking the timing light reading off of either #3 or #2 spark plug cable.
Engine runs, lack of power, timing light 180 degrees off, ='s, two of the spark plug cables are attached to the wrong plug.

One thing I didn't think to add yesterday, is that trying to time a Cub using a timing light is a waste of time. You time them by ear.

Matt Kirsch wrote:One thing I didn't think to add yesterday, is that trying to time a Cub using a timing light is a waste of time. You time them by ear.

I understand this theory IF the cub does not have a 16 degree timing mark. I don't understand the theory if it does.
Please share because later model cub manuals walks you through it using a timing light. (later models have points & two timing marks)

While I haven't had to do it with either of the three Cubs in my stable, I can tell you that my '51 M ran...not awful, but not great when I initially timed it to the mark. Loosen that clamp and twist that distributor ever so slightly till it just sounds smooth...my "M" will idle at around 350rpm, smooth as silk. The ol' girl just has too much wear in the timing gears to be right on the money by the light...

outdoors4evr wrote:

Matt Kirsch wrote:One thing I didn't think to add yesterday, is that trying to time a Cub using a timing light is a waste of time. You time them by ear.

I understand this theory IF the cub does not have a 16 degree timing mark. I don't understand the theory if it does.
Please share because later model cub manuals walks you through it using a timing light. (later models have points & two timing marks)

I'm not understanding this either. I've literally timed dozens upon dozens of Cubs (I own more than 12 myself!), never mind the other types and sizes of tractors I've laid my hands on, and I've never thought of a timing light being a "waste of time", quite the opposite. Even on a Mag I still like to use one to confirm the automatic advance.
I understand the idea that there are folks that don't like a timing light, don't own a timing light, or prefer to hit the sweet spot by ear. But that hardy means that using a timing light is a waste of one's time and effort, especially for those that are new to tractors and old engines in general.

Timing by ear My ear is different than yours

I had low power until I read to set Idle speed low when timing and reset afterwards. light and dwell meters work well for me. Not sure what to make of your 180 out. somethings not right

Sorry the video is crooked. I'll turn the camera next time. Make sure your sound is on.

http://youtu.be/2dzhS0j8PW4

The link doesn't work