2 cycle compression ......
 

On 3/26/2012 8:45 PM, Steve B wrote:
I have a 21cc hedge trimmer. A Craftsman. It hasn't run for a while, but
the guy swore it was running when put up.

I put new gas in it, and checked the obvious. It needed a new on/off
switch. It has spark. I can't get it to pop, even with shooting a little
gas into the carb, or on the sponge air cleaner.

When I pull the start rope, there isn't very much "POP" at all. I mean
resistance that would come from good compression, or from firing and
igniting the gas/air mixture.

Just how much "POP" should be present, even if you have the switch off, and
aren't trying to start it, but just basically see how much compression it
has? I call "POP" that instantaneous resistance on the pull rope where it
would hit TDC, or fire with a spark. Does two strokes not have the "POP"
that four strokes have because of their different configuration?

Tomorrow, I'll pull the carb and see if there's anything obvious there. The
primer bulb worked, no leakage, and filled up, presumably feeding gas to the
carb.

Steve

Last year in August, I bought a little used but older Stihl chainsaw
from the local Habitat for Humanity Thrift Store. It ran good. It was
very dirty and needed a cosmetic cleaning job. Seemed to have good
compression. And, it was only $50. I used it once in December and it
started and ran great. This year, I tried to start it and nothing.
Well, ok, there was an occasional pop, but few and far between. I
checked the plug and it was wet. Dried it off and tried and tried and
nothing. Emptied the gas and put in clean gas/oil. Stihl nothing :) I
then put in a quick squirt of starting fluid in the plug hole,
reinstalled the plug and tried again. After maybe 10 pulls, it started
without the choke (only on or off) and full open throttle. It seems ok
now. I used it the next day. The 1st time it took about 6 or 8 pulls
before it started. After that, only one pull. BTW, I think this thing
had the original chain, apparently never sharpened and still very sharp.
Of course I can't tell for sure, but it everything points in that
direction. So it must have been owned by someone who just used it a few
times, spending most of it's life on the shelf with all the oily sawdust
just left there.

2 cycle compression ......
 

Ether in the spark hole dries the oil out of the cylinder wall. Can result
in piston locking up, or worse, thrown piston rod. Happened to me.

My Dad's generator didn't start. During a power cut, of course. A "helpful"
neighbor sprayed ether in the spark hole. Locked up the piston. Dad went and
bought another generator.

Dad gave me the broken generator. I freed the piston, and negelected to
reoil the cylinder bore. The motor started, ran half a second, and threw a
piston rod. Turned a $500 generator into a $75 ebay sale "as it". I was
disappointed.

Ether in the spark hole, at your own risk.

Christopher A. Young
Learn more about Jesus
www.lds.org
..

"Art Todesco" wrote in message
...
checked the plug and it was wet. Dried it off and tried and tried and
nothing. Emptied the gas and put in clean gas/oil. Stihl nothing :) I
then put in a quick squirt of starting fluid in the plug hole,
reinstalled the plug and tried again. After maybe 10 pulls, it started
without the choke (only on or off) and full open throttle. It seems ok

2 cycle compression ......
 

On 3/27/2012 9:52 AM, Stormin Mormon wrote:
Ether in the spark hole dries the oil out of the cylinder wall. Can result
in piston locking up, or worse, thrown piston rod. Happened to me.

My Dad's generator didn't start. During a power cut, of course. A "helpful"
neighbor sprayed ether in the spark hole. Locked up the piston. Dad went and
bought another generator.

Dad gave me the broken generator. I freed the piston, and negelected to
reoil the cylinder bore. The motor started, ran half a second, and threw a
piston rod. Turned a $500 generator into a $75 ebay sale "as it". I was
disappointed.

Ether in the spark hole, at your own risk.

Christopher A. Young
Learn more about Jesus
www.lds.org
.

"Art wrote in message
...
checked the plug and it was wet. Dried it off and tried and tried and
nothing. Emptied the gas and put in clean gas/oil. Stihl nothing :) I
then put in a quick squirt of starting fluid in the plug hole,
reinstalled the plug and tried again. After maybe 10 pulls, it started
without the choke (only on or off) and full open throttle. It seems ok

Not to say that it won't dry out oil in the cylinder wall, I don't know,
but .... I've used ether in most of my small engines at one time or another
and haven't any problems.