Cub Timing Problems

Sun Mar 24, 2013 7:52 pm

Cub has a mag. It runs perfect only, cylinder 1 is 4 on the dist. cylinder 2 is 1 on the dist. Cylinder 3 is 3 on the dist. Cylinder 4 is 2 on the dist. What is going on?? I have pulled the dist/ mag out 1000 times. Wires have to be crossed for it to run as good as it does.

Re: Cub Timing Problems

Sun Mar 24, 2013 9:47 pm

Have you checked to see if the rotor is timed correctly? There are two raised marks on the gears that must lined up. Hope this helps. Welcome to the forum!!
Bill

Re: Cub Timing Problems

Sun Mar 24, 2013 9:54 pm

Yes. The mark on the small gear is aligned to the mark on the rotor gear.

Re: Cub Timing Problems

Sun Mar 24, 2013 10:14 pm

I have 8 different sketches trying to figure out the presented firing order. Firing order is 1, 3, 4, 2 with number 1 cylinder plug wire at the 12 o'clock position on the distributor. Running clock wise from the operators seat.

Operator's manual for your tractor, free down load, manuals at top of this page, has pictures of the correct magneto spark plug wire locations.

Should your spark plug wires not be in the correct location - and yet the tractor runs great - you have two choices. Either leave things alone or retime the rotor location within the magneto's distributor.

Re: Cub Timing Problems

Sun Mar 24, 2013 10:20 pm

apprentice wrote:Yes. The mark on the small gear is aligned to the mark on the rotor gear.
Remove magneto, back up drive lug 180 degrees, reinstall. Then reinstall the plug wires in the correct location - static time engine.
Last edited by Eugene on Sun Mar 24, 2013 10:20 pm, edited 1 time in total.

Re: Cub Timing Problems

Sun Mar 24, 2013 10:20 pm

The governor timing maybe incorrect. Check out this thread.
viewtopic.php?f=1&t=63072&p=515656&hilit=govenor+timing#p515656

Re: Cub Timing Problems

Sun Mar 24, 2013 10:35 pm

If i remove the mag and mannuelly turn the drive prongs backwards 180 degrees the rotor then will be facing 180 out. Do i have to unbolt the rotor and rotate it 180? Then the marks on the rotor gear wont match up to the little drive gear. i believe there supposed to.

Re: Cub Timing Problems

Mon Mar 25, 2013 5:14 am

To fix it properly:

align cylinder 1 (closest to radiator) to TDC
remove mag, check that governor drive lugs are at app. 2 and 8 o'clock; if not, remove governor and correct
insure rotor and pinion are aligned (you state this is so, be sure)
install mag with rotor pointing as close as possible to #1
static time the engine

There are posts on here about correcting the governor (with pictures of correct), and static timing, if needed.

Re: Cub Timing Problems

Mon Mar 25, 2013 6:49 am

Engine is at tdc of compression stroke. Rotor strait up and down. Both gears alligne d. Engine starts butthere is no throttle. Swap the #2 wire with #1 wireawireand everything is fine.

Re: Cub Timing Problems

Mon Mar 25, 2013 9:36 am

apprentice wrote:Engine is at tdc of compression stroke. Rotor strait up and down. Both gears alligne d. Engine starts butthere is no throttle. Swap the #2 wire with #1 wire and everything is fine.


Therein lies the problem: Rotor should be around 1 to 2 o'clock when at TDC on Compression Stroke. Timing is of if # 3 plug fires properly in the #1 tower.

Check out How To Understand Firing Order

Re: Cub Timing Problems

Mon Mar 25, 2013 11:16 am

So I need to pull the mag. Rotate the. Drive lugs until rotor is at. One or two o'clock and make sure the marks are aligned on the two plastic gears. Is this what you are saying?

Re: Cub Timing Problems

Mon Mar 25, 2013 12:00 pm

apprentice wrote:So I need to pull the mag


Sort of. To fix it properly, you need to pull both the mag and the governor. Then reinstall the governor, so the slot on the back of the governor drive gear is at 2 and 8. As Rick suggested, do a search on the forum for one of the threads on reinstalling the governor. There are dots on the gears that need to be lined up. Then reinstall the mag and static time the mag.

Here's the page from the service manual that describes it, but there are threads that have actual pictures that are even better.
Image

Re: Cub Timing Problems

Mon Mar 25, 2013 12:23 pm

The governor notches are at 2 & 8 wh en at tdc. Thhat has always been ok. When. I roll the engine over and stop it at tdc of comp. Stroke the rotor is pointing around 1 & 2 o'clock. This is why im confused. It will start and run but. Better if I swap #1 & #2 around.

Re: Cub Timing Problems

Mon Mar 25, 2013 1:49 pm

Engine runs - good - things are not to far off.

Roll engine over to #1 cylinder TDC. Then static time the magneto. Check rotor location - should point straight up to the #1 spark plug tower location on distributor cap. Check to see that the spark plug wires from the distributor cap are going to correct spark plug.

Re: Cub Timing Problems

Mon Mar 25, 2013 2:20 pm

Eugene. This is where my problem is. At tdc on #1 the rotor is point ing to number one .plug spot .wires have to ve swapped from #1 & #2cylinders to run correct . Why???