Rotavator won't start

Habbakuk

When I pull the starter lead, sometimes I get the odd hint of ignition but it doesn't start up. When I do pull the starter lead, smoke does come out of the exhaust. I suppose this msut mean that the fuel is being burned but not correctly. Any advice?

PS The fuel is fresh and mixed at the correct ration of 25:1 for a two stroke engine.

Thanks.

spacey2012

Check the plug gap, they open themselves up with use.

pogg000

New sparkplug?

GlynD

Either take the spark-plug out, clean it and reset the gap or buy a new spark-plug and set the gap correctly. If you don't have a feeler gauge then take the plug to a local garage and they'll set the gap for you.

That might not be why the machine isn't starting but it's the most logical and easy place to start. Also, make sure the fuel filter is clean.

Habbakuk

Somebody here is telling me that it's the plug lead since it does have bare wire in some area and there is not cap fitting onto the plug. But I've now but tape over the bare part and since it's combusting a little, the the connection must be there. So it's likely to be the plug? Any thoughts?

JohnB47

Here's a thought.

Take the spark plug out and make sure it is relatively clean and that the gap is correct. Give it a good wipe to make sure it is free from fuel - perhaps leave it to dry out for a couple of hours indoors first, just to be safe. Then put it in the oven and heat at about 130 degrees for about ten or fifteen minutes. Wrap it in foil if you're worried about smell.

Then, wearing suitable gloves or using a dry cloth, put it immediately back in the machine and try starting it. If it works, run it for a good time 'til it's nice and warm.

I used that trick to get my Mazda 323 estate going back in the eighties when the temperature was sub zero for a few weeks. It was probably the battery that was a bit clapped out but heating the plugs made the engine start up immediately.

Habbakuk

I'll be back now. I've got what the spark plug type should be which is a NGK B6H. I'm going to check what's on the machine.

GlynD

JohnB47 wrote: »

Here's a thought.

Take the spark plug out and make sure it is relatively clean and that the gap is correct. Give it a good wipe to make sure it is free from fuel - perhaps leave it to dry out for a couple of hours indoors first, just to be safe. Then put it in the oven and heat at about 130 degrees for about ten or fifteen minutes. Wrap it in foil if you're worried about smell.

Then, wearing suitable gloves or using a dry cloth, put it immediately back in the machine and try starting it. If it works, run it for a good time 'til it's nice and warm.

I used that trick to get my Mazda 323 estate going back in the eighties when the temperature was sub zero for a few weeks. It was probably the battery that was a bit clapped out but heating the plugs made the engine start up immediately.

That's a superb trick. I'd forgotten about it but you're absolutely right - it works a treat, even in sub zero temperatures. I think we've all been there in the 70's and 80's. The old "I had a car like that once" syndrome. :cool:

Habbakuk wrote: »

Somebody here is telling me that it's the plug lead since it does have bare wire in some area and there is not cap fitting onto the plug. But I've now but tape over the bare part and since it's combusting a little, the the connection must be there. So it's likely to be the plug? Any thoughts?

Changing the plug lead to a good insulated one with a plug cap won't do any harm. I presume this is your own machine? If it's a hire I wouldn't be spending any of my own money on it at all.

Stooby2

Have you emptied the carburettor of fuel? If there was any left in there it will have gone off as well and will need draining and refilling with fresh fuel as well as the tank.

Habbakuk

Habbakuk wrote: »

I'll be back now. I've got what the spark plug type should be which is a NGK B6H. I'm going to check what's on the machine.

Just went down to see it and the above plug is specified in the manual. However, on the machine at the moment, is a plug B4-LM. Is there anyway of telling is this is fine?

Draining the carb seems to be a biggish job. I had a look for the drain just a minute ago but couldn't find it but it's getting dark and there wasn't very good light. Thanks for all suggestions so far.

Habbakuk

Does anybody know if the B4-LM and the NGK B6H and interchangeable?