On Mar 26, 6:32*pm, "Steve B" wrote:
"Tony Hwang" wrote in message

...







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

Hi,
Take a look at the spark plug. To check a compression I remove plug and
plug the hole tight with chewed paper ball. When you pull the cord, it
should pop out. Is choke working? Try new spark plug or heat it on the
range heater and make it dry. Hope you did not mix in too much oil.

Plug is absolutely new and dry. *Even when I shoot some gas into the carb
opening with a syringe. *Even with shooting a small amount of gas into the
plug hole, reinstalling plug, and pulling cord. *I suspect I need to take it
off tomorrow and see what's up.

I got an edger going today, a 3.5 hp Briggs, but it doesn't run very well,
and the thing will only run with both jets at about 3/4 turn open. *Can't
get it to run up to very high rpm by adjusting the jets. *Took off the
diaphragm cover, but just the cover. *There was sand. *I didn't have a
replacement diaphragm, and that one was on there pretty tight, so chose to
just leave it alone, thinking it might run. *Obviously, I need to get a carb
rebuild kit and go through it. *First, though, I'll take a razor knife and
see if I can get the diaphragm/gasket off, and clean behind it, then reuse
it.

With these little carbs, just a little bit of junk will make a big
difference. *They're like working on watches.

Steve

Could be it was straight gased, pull the exhaust and check for scoring
on hthe pison/jug.

Harry K