Timing help

Sun Oct 20, 2013 9:11 am

Can someone tell me the proper way to time a cub with a distributor? I put a timing light on my cub yesterday and the timing mark on the crank pulley was about .5 - .75 inches past the pointer (clockwise). It's my understanding that cubs are supposed to be set at TDC. I'm wondering if this might be the root of my problems instead of the carburetor. Can the distributor be loosened and turned like a car distributor or does it have to be removed and reinserted in the correct position? I can only find instructions for mag ignitions.

Re: Timing help

Sun Oct 20, 2013 9:57 am

Just loosen the clamps on the front and rear of the distributor. The rear one may be missing and read here.


Re: Timing help

Sun Oct 20, 2013 10:08 am

Since engine is running and you have a timing light.

Mark (chalk) the TDC notch on the pulley, 2nd notch to pass the pointer if the pulley has two notches.

Yes, distributor can be loosened and turned just like an automobile. Note, there is a 2nd bolt and clamp on the back side of the distributor, next to engine block. Loosen but do not remove the bolt next to the engine block.

Start engine, loosen front bolt, gently rotate the distributor - just a smidgen - try clock wise first. Check timing at low engine idle. TDC mark should line up with the pointer.

If engine is hard starting, it helps to have an assistant (3rd hand) to pull the starter rod to crank engine while you turn the distributor.

Re: Timing help

Sun Oct 20, 2013 1:33 pm

If your crank pulley only has one mark it was originally on a tractor with a magneto. that mark is the TDC mark. If you have a timing light that has an adjustable advance you can set it at 16 degrees to time. If not, put a mark on the pulley approx. 21.5/32 before the mark and time to that with engine running.

Re: Timing help

Sun Oct 20, 2013 7:12 pm

It has two marks on it. I haven't tried to time it yet. I was finishing up some other stuff today.

I will admit the carburetor adjustments are really irritating. I bought a brass fitting and some clear hose to check the bowl level and thought it was too high. I had gas seeping around the metering rod and around the plug on the bottom of the bowl. So I used a piece of heavy paper and cut a notch one inch wide and 1 3/8" deep to set the float. I haven't tried to start it since then, but I hope it works out. I will more than likely tinker with the timing and test the carb tomorrow.

Re: Timing help

Sun Oct 20, 2013 9:24 pm

Well, I couldn't wait until tomorrow. I went out in the garage and made a makeshift gas tank from a Lucas 80-90 bottle and plumbed it in with my trusty clear fuel line I bought this morning. I started it up and set the timing to the second mark (clockwise) guessing at around 4-500 RPMs. It runs like a top now. All the black smoke is gone, and no drips from the carb. It still has an occasional puff of blue smoke when I gag the throttle, but I am hoping after some running time it will go away too. I reattached the air cleaner and governor linkage then let it run for about 15 minutes until it ran out of gas. I don't even have to choke it to start it anymore. :D

I did notice some water leaks. I replaced every water gasket on it when I reassembled it. Should I have used some type of dressing? I just assembled it with dry gaskets.

I'd like to thank everyone again for all their help. I truly appreciate it.

Re: Timing help

Mon Oct 21, 2013 11:20 am

Jason_Coffey wrote:I did notice some water leaks. I replaced every water gasket on it when I reassembled it. Should I have used some type of dressing?
I use a non hardening gasket cement on hose connections if the metal stem is corrosion pitted.

On flat mating I just scrape off the old gasket from both surfaces. Sometimes I have to use sand paper to remove small pieces of the old gasket. Check for flatness, then assemble with out gasket cement.

But, sometimes a gasket sealer is called for.