I would verify that you have a good connection between the spark plug threads and ground when testing for spark. If just laying the spark plug on top of the cylinder head fins there may be enough corrosion on the surface of the fins so that spark would appear to be intermittent and / or weak. In some parts of the world where someone is situated near salt water (England near the coast comes to mind) the corrosion might even become bad enough that the cylinder head may have some resistance between it and the actual engine block resulting in a poor connection to complete the secondary ignition coil circuit. Could check for resistance between the spark plug threads in the head and the block - should be zero. Another possibility might be that the surface of the points contacts are becoming coated with an insulating substance - engine oil seeping into the points area from a leak? A broken wire internally providing an intermittent connection also is another possibility. If this is a magneto system and a switch grounds out the points to shut the engine off the switch could be intermittent and partially shorting the primary ignition circuit to ground in the on position. Just some things that come to mind that you may not have checked - it could also be that one of the new components is defective. Hope this helps.
Howard 350 fitted with a Kohler 8 Hp motor ...
Problem is when engine was cleaned up and reassembled it started on third pull great , ran for about 5 minutes and stopped not to go again . NO SPARK Cleaned everything up again but still no go (spark ). Fitted new coil ,points ,condensor and had the magnets recharged , put things back together just temporary and hay presto good spark (spun fly with battery drill ) so tightened Flywheel and remade all connections proper and permanent guess what NO SPARK .
Went and had cup of tea , returned spun the wheel again and hey presto we had SPARK again BUT you could see it ( spark ) getting weaker , weaker till there was none again , I can’t seem to get back .Can somebody help .Specs of engine are -: model K181T , serial no 11074181. , spec no 30449D , thanks all ,Mike. .
Went and had cup of tea , returned spun the wheel again and hey presto we had SPARK again BUT you could see it ( spark ) getting weaker , weaker till there was none again , I can’t seem to get back .Can somebody help .Specs of engine are -: model K181T , serial no 11074181. , spec no 30449D , thanks all ,Mike. .
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Thanks for your suggestions, I have polished,cleaned ,and ground all earthing points for a good contact , use a jumper wire for earthing the spark plug , it has got me stumped , This is a magneto system and no kill switch is employed at this point , thanks Mike .
Could disconnect the wire(s) connected to the points and then check for resistance from where the wire(s) connect on the points to ground (earth) - reading on ohmmeter should be infinite with points open and zero with points closed. An intermittent (partially shorted) condenser can sometimes create the problem you are describing as well. I am wondering if something in the points set or connected to the primary winding circuit is allowing a partial path to ground and not allowing the primary circuit to function properly all the time?Thanks for your suggestions, I have polished,cleaned ,and ground all earthing points for a good contact , use a jumper wire for earthing the spark plug , it has got me stumped , This is a magneto system and no kill switch is employed at this point , thanks Mike .
We have tried changing points and condensers and coil still to no avail ,I was wondering if I packed the magnets to bring closer to the yoke on the coil if that would help. Of course it is a under Flywheel setup which should be spot on . On checking the points with a meter on opening and closing the come up ok .Considering getting a new coil and condensor and starting again . I’m really running out of ideas ,thanks Mike .
About the only other thing I can think of is that the plunger is not opening / closing the points consistently - perhaps hanging up a bit at times?? Would think if it was the spacing between the coil and flywheel the problem should be consistent unless there is up and down movement in the crankshaft resulting in the spacing between the coil and the magnets changing.We have tried changing points and condensers and coil still to no avail ,I was wondering if I packed the magnets to bring closer to the yoke on the coil if that would help. Of course it is a under Flywheel setup which should be spot on . On checking the points with a meter on opening and closing the come up ok .Considering getting a new coil and condensor and starting again . I’m really running out of ideas ,thanks Mike .
We checked out everything mentioned, all ok . Kept coming back to the coil so ordered a new one , we feel sure the new coil that was fitted was a bum one , worked some of the time . Thanks for your help and suggestions , Mike .
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