Okay, I know people are going to say rubbish, dangerous nasty cheap...
But I have had my £70 special for a few years now, it came with an alledgely decent bar and chain 'oregan' but I have my doubts any.
Cutting wood today merrily, fitted a new oregan bar and chain last week and it has greatly improved performance until it just stopped dead, engine
just died away.
Started taking it apart, when pulling over lots of air spurting out the carb, thinking hole in piston stripped it down and found the fault, sticking
piston rings.
The piston has little pegs stopping the rings from circiulating around the piston in use, never seen this before but found the culprit as it looks
like when they install the piston rings they crimp the piston to hold them in place before assembling, the piston rings were stuck at 3 & 9
o'clock and the piston has maybe 10thou deep 1/8" wide even crush lines.
All very odd, anyway cleaned the grooves up so the rings fit correctly, still unable to rotate and its running again.
Has anyone else seen anything like this?
Cheers Mark
I'm presuming that the chain saw is 2 Stroke? If so the rings need to be pinned to stop rotation, if not the rings will catch on the ports and
snap= seize solid/wreck the bore etc, if it's a 4 stroke sod knows.
Shooter
I agree , normal with two strokes .
60cc two stroke, it's crimping the rings to the piston that seems really odd.
As said, normal on a 2 stroke.
By crimping do you mean like a circlip style fitment? The rings should float but not rotate.
I have all sorts of cheap Chinese tools, screwfix specials, Aldi deals etc. Love them, I would buy most of my titan tools again if they broke.
And I have a Stihl chainsaw. I always say to people 'the minute you disrespect a angle grinder it' ll take a finger, the minute you
disrespect a chainsaw it will take your leg'
Too scary, you can't even buy Stihl saws online. The dealers vet you (or should) on purchasing to see if your responsible enough.
quote:
Originally posted by bi22le
As said, normal on a 2 stroke.
By crimping do you mean like a circlip style fitment? The rings should float but not rotate.
Are you sure the engine hasn't 'eaten' something, and that's done the damage to the piston at tdc before getting out of the
exhaust port.
Ian
Exhaust port is out the front, inlet from the back, the piston has been pressed at 3 o'clock and 9 o'clock, same width, same depth and has
been machine generated, it must have been the tooling that inserts the piston clamping it to hard I guess.
Never the less, it still fires up and runs cleanly now although on borrowed time.
The piston is made of remarkably soft material, quality it is not.