Had a problem with the pole saw chain stopping
when put up to cut something. Lost the plastic retaining
inset that stops the drive rod from slipping out of the
shaft a few months back, and therefore assumed it was
something connected with this. So examined all the gear
cogs and tested their turning capabilities while restraining the
drive rod with pliers. Came to the conclusion that they must be
jumping apart because of the lack of this component.
Got a new one, but this didn't work, took it apart again and greased
the cogs, tried again, flippin chain on backwards... lol but confident that
it felt better, turned chain around, - back to square one.
Took it all apart and removed the bar, cleaned the dirt away and found
cog that drove the chain, discovered that this had a circular hollow centre
but the drive shaft was an symetrical longated oval shape...
(not sure of the correct name lol ) Thought at first that the circular shape
in the centre of the chain cog had been etched out by friction, but it was too
uniform and there were no left metal filings. Realised that this shape enabled
a certain amount of give/slip in an emergency thereby reducing any damage.
Then looked at all the spring washers surrounding this cog and realised that
these had to be pushing down fairly firmly to stop this cog slipping.
Tightened the screw in the middle of the washers and tattaaa it worked.
Made a mental note - next time flippin well ask about the problem on LJN :)
Ive had the same sort of problem on my castle strimmer had it 8 years, then all of a sudden the engine would rev but not the head, took it apart no visual problems all intact, fitted it back together still would work got frustrated with so i banged the head on the ground while reving the engine, all of a sudden it works, two minutes later it stopped found it to be a metal clip that is crimped round the flexi shaft was slightly worn and was moving about 2-4mm and that was simply the problem.