Won't start anymore...

[spray004]

Well got to work on the Cub again this weekend. I rebuilt the carb & replaced the coil. The first time I worked on it (bout a month ago), the tractor ran for 20 min and shut off. It would crank up, run for a bit and shut back off. So I was thinking the coil was bad. Well now the tractor won't start at all. I got a regular 6V coil from O'Reillys ($13). I pull a plug and checked for spark and got none. I pulled the cap as well. The rotor is new, the points are new (new looking, last tune up could have been years ago but this tractor has been parked for a couple of years), the condensor is new looking as well. I didn't have a multimeter to test anything. The tractor did crank up for about 10 seconds, but it went dead and never would start. Any ideas? Also I plan on trouble shooting it next time. Any steps on how to trace the problem to the source? I'm thinking it has to be somewhere in the distributor.

[beaconlight]

Welcome Spray to the forum. The most common reason for the cutting out is a loose connection either hot side or ground. Another one is carbon on the inside of the dist cap. A bad condenser could do it too. Points could cause it too, but sometimes yes and sometimes no tends to rule them out. A coil could cause it too. A bad carbon pick up in the top of the Dist cap to the rotor could cause your problem too. Some exotic and rare things could too, such as bad distributor drive. Try the cheap ones first. If you don't have a multi meter you could check all your connections to make sure all of them are tight and clean. No rust or corrosion. You can use a lamp in place of a multi meter on the low voltage side.
Look at this link
http://www.farmallcub.com/HLChauvin.htm
There are three sections on won't start.
Bill

[George Willer]

More common than electrical problems are fuel flow problems. The tractors run cheap, but are hard to start. Pull the plug on the bottom of the carburetor and look for good SUSTAINED flow.

[beaconlight]

I know what you are saying George and it is more common but I was addressing the fact he said no spark. If he was in a northern clime I would have mentioned ice in the carb or fuel line.

Bill

[cowboy]

Hi Spray

Just because it looks new doesn't mean that its clean or good. Clean the distrubuter out with starting fluid or contact cleaner do not use carb cleaner that will leave a little film on everything. and I would file the points. I was working on a lawn tractor had a little spark lost it got it back lost it tried three different coils on it and it was just a little oil on the points that I couldn't see.

[George Willer]

I know what you are saying George and it is more common but I was addressing the fact he said no spark. If he was in a northern clime I would have mentioned ice in the carb or fuel line.

Bill

Bill,

Of course you're right. It was an oversight on my part. I didn't read carefully enough. Sorry.

[spray004]

I'll have dad file the points one weekend (I live 2hr away). How can I test the condensor and coil? The plugs aren't fouled, although I'll be replacing them anyhow. Also how many Ohms are tolerable for the plug wires?

[beaconlight]

I don't even think of testing condensors. They are so cheap it doesn't pay besides if that is not the problem you have one for next time. The plug wires should be the old fashioned copper type. Therefor except for bad corrosion at the connectors you should not have a problem there. I use my old telephone contact burnisher on the contacts. Cowboy covered what I was trying to say much better than I did. about cleaning the Dist cap. They are shinny hard black when new and turn grey and sort of sandy feeling when exposed to the elements for a while. Quite frankly I replace the points and condensor when I have no spark. I even burnish new points because of the possibility of an oily film. If that works I am home free. If that doesn't work I change the cap and maybe the rotor. When doing the points I check and clean the cap. You can set the points, rotate the engine till the points are making then open and close the points and you should see a spark. If the coil has a good primary winding. I have seen the brass end rot off the end of the rotor. It happened on my neighbors C twice in the past 20 years. If I have done all this and no spark it time for a coil change.
I mention it last but before I do all of the above I check for good electricity both hot and ground. You can do it with a light bulb if no multi meter. If you get the small spark when you manually open and close the points, you know the low voltage is good. The vibration of running or the heat of running for a while can cause condensors or coils swing good and bad.
George mentioning gas is not any thing to apologize for. Once you have spark that is needed. These 50 year old fuel tanks we all have shed all kinds of debris. I have cleaned mine finally. At one time every time I hit a bump the engine would cut out. If I pulled the choke out I could keep it running. 3 or 4 bumps later it would run ok again. After reading on the forum about draining and filtering the fuel till clear, I did it and no more problem.

Bill

[Eugene]

Home owner grade multimeters can be purchased very cheaply, $10.00 range, at your local hardware, automotive, or electrical supply store.

Multimeters of this quality work well for automotive (DC) and home (AC) electrical checks. They are not designed to check high amperage levels.

Biggest caution with a multimeter is to not have the leads connected to anything when changing ranges. For the novice, purchase the inexpensive multimeter. A mistake will burn out the fuse. You can purchase another multimeter for slightly more then the cost of the fuse.

Eugene