B starting problems

Some times I pull the starter leaver and she fires straight away, most of the time I I have to turn her over and over again. I’ll drive a couple of hundred yards she’ll cut out then doesn’t like to start. The previous owner fitted new manifold and carb, plugs and leads. He could start it easily with the crank I could never get it started that way. I have tried checking the timing and it seems ok. Any ideas would be appreciated. Thanks

First off, welcome to the forum.

My first though is a fuel problem. If your tractor has a sediment bowl on the tank, take the bowl off and check that the screen isn't plugged. Then with the bowl off, open the valve to verify you have a good flow.

if you can hand crank start a tractor, and the electric starter is hard to start... it can be the impulse in the magneto. Hand crank starts at ZERO rpm so the motor fires at TDC and easily starts... SPIN the motor, especially with 12v and if the impulse throw out weights do not GRAB, then the motor fires at the FIRE mark or 30 degrees before top dead center.. VERY HARD to start at that point... You may need some work done on the impulse / spring / weights / small springs on the weights inside the Mag front end..

Edited by steve(ill) - 31 Aug 2024 at 7:39am

Thanks for the advice, I’ll order a 6v battery. What Ah is best ?

It is correct that a 12v battery spins the starter faster and is probably a little harder on the starter nose and ring gear.. That being said, there are TENS OF THOUSANDS of old tractors now running 12v batteries in them without problems. Many of the "bad ring gears" and such were from WORN OUT 50 year old tractors before the 12v battery was installed. I have 6 tractors with 12v batteries and all run great. YES, they do spin faster and YES, you have to have a GOOD MAG and GOOD IMPULSE to get ANY TRACTOR to start. My main tractor starts in 1-2 revolutions of the engine...has had a 12v battery for 20 years.... starts just as it would when you did a manual crank start... really dont have time to "get up to high rpm" with the 12v starter.

Edited by steve(ill) - 01 Sep 2024 at 8:20am

So I’ve got a 6v battery, bearing in mind I have no other electrics fitted, dynamo etc, should I still have a positive earth or doesn’t it matter?

So I’ve put a 6 volt battery on, when the switch on the starter is pressed I get a lot of sparks and smoke from the switch, and the starter barely turns the engine. I bought a new switch, and that does the same. The contact on the starter seems very worn. Can that be changed ?

Unfortunately there isn’t any repairers near me. The starter cost the equivalent of $650 USD here in the UK. I new it was a risk but didn’t really have another option