Won't start

bigtiller · Sep 21, 2007

I have a JD 3020 gas that became hard to start today. It will not fire now when trying to start but if I spray ether into the carburetor it will start right up. My first guess would be a week coil. any body have an idea what to do to get it going again?

After getting it running with ether, it sounds smooth. The points, rotor and distributor cap look fine but it was to dark to check the deual or point gap.

TedLaRue · Sep 22, 2007

You may be right about the weak spark from a weak coil, but there could be a variety of other causes.

I don't think the dwell angle/point gap is a problem. The dwell angle is the number of degrees that the cam shaft (or distributor shaft) rotates when the points are closed. At low RPM (like when you're cranking the engine to start it), the points are closed long enough to charge the coil even if the dwell is off a bit.

The dwell/point gap also affects the timing, but with normal wear it will ****** the timing which normally makes an engine start more easily.

You say it runs ok after starting it with ether. Check the choke. It may be stuck open (no choking the air so you don't get the rich fuel mixture needed to start the engine).

You can check for weak spark by pulling the coil wire off the center of the distributor cap, sticking your finger up in the cap on the end of the wire, leaning on the frame of the machine and having someone crank the engine. The strength of the spark is indicated by the quality of the expletive you use.

Alternatively, you could pull a spark plug, reattach the spark plug wire, lay it on the engine block so that it is grounded, and then observe the spark as someone cranks the engine. A strong spark will have a blue snap. The spark itself is hard to see unless the plug is shaded.

zzvyb6 · Sep 22, 2007

You seem focused on spark/electrical. Have you checked for a vacuum leak, a clogged fuel filter and water in the carb bowl? Crank rpm and idle rpm are so different that fuel systems can be inoperative at low crank rpm. If you roll start it by parking on a hill and releasng the clutch at a moderate speed, will it fire right up? If so, look for a fuel or vacuum problem.