PDA

View Full Version : OT: small 2 stroke doesn't run



CompositeEngr
04-18-2006, 11:49 AM
unless I keep it on half choke. Seems to run OK on half choke. The throttle response is a little slow. Even after running for 20 minutes on half choke, opening the choke causes it to die.

This is a newer weedeater. It started this at the end of last year (its first season, and then only was used 5 or 6 times).
Don't buy the cheap homelite.

What would be the cause of not wanting to run with the choke open? What would be the worst that would happen if I keep running it with the choke half closed?

DICKEYBIRD
04-18-2006, 12:05 PM
Since it's so new, it's probably not the normal high-time problems like loose carb or crankcase bolts (air leaks) or worn out crank seals. Have you tried opening up the main mixture needle a half-turn or so? Could also be a piece of trash in the carb, most likely at the diaphragm needle/seat or the main needle.

topct
04-18-2006, 12:10 PM
It sounds like the carb is plugged somewhere. It will need to be cleaned out. Or did someone try to adjust it?

I might check the carb mounting bolts. If they are loose it will cause the engine to go lean also.

As far as running with the choke on, it can't be running very good that way and will foul out the plug.

This kind of problem is common and the brand doesn't matter. I've worked on the high priced ones, those and the leaf blowers and chain saws all can suffer the same problem.

skeeter
04-18-2006, 12:36 PM
I believe as the others stated, the engine is running too lean.

The present day units, weed wackers, blowers, etc., are all being built to run as lean as possible.

I have a new leaf blower that runs too lean. I took the carb and cut some slots in the heads off the mixture screws, so that I could adjust the mixture. The thing came without any slots,on these needles, so very hard to move or adjust.

Opening the hi-speed needle helped mine run much better.

One other thing that might present a problem is that a dirtdobber has plugged the exhaust.

vmil3
04-18-2006, 01:34 PM
Check you fuel line in the tank, these newer ones fail, they split at the filter causing the carb to suck air, like running lean. Also check or replace the fuel filter as mixed gas tends to plug it up.
Doug

lynnl
04-18-2006, 01:44 PM
As I was reading the reponses I was having the same thought Skeeter mentioned - dirt dauber mischief.

Those little bastards have plugged up the exhausts in my weedeaters several times. First time it happened, I didn't find the problem until I'd completely disassembled the whole thing. But the next time it didn't run right I knew what to look for.

Finally I wised up and starting storing it with a plastic bag wrapped around the powerhead.

Fasttrack
04-18-2006, 07:20 PM
Along with everything else i would check the fuel line, as Vmil3 mentioned. The newer weed wackers and etc have some cheap fuel line that seems to dry out if not always submerged in fuel. I do alot of small engine work for neighbors and etc - i've had three weedeater brand weed wackers that had varying degrees of fuel line distengration. One had completely busted apart, the fuel filter and a bunch of pieces of fuel line were sitting at the bottom adn the machine was only three years old!! The owner did say it sat for about a year with no fuel in the tank which is, in my opinion, what caused the fuel line to bust up like that.

motorworks
04-18-2006, 10:23 PM
"This is a newer weedeater.... only was used 5 or 6 times."

That's about as good as it gets from a weedeater.
When I did small engines in my shop, we would NOT take weed eaters in for service.
Next time buy a Shindaiwa, you can put it in your will!!

wierdscience
04-18-2006, 10:53 PM
It might be constipated,check the spark aresstor screen on the muffler and see if it isn't clogged up with carbon and goo.

IOWOLF
04-19-2006, 05:00 AM
It might be constipated,check the spark aresstor screen on the muffler and see if it isn't clogged up with carbon and goo.

I have seen this on my own string weed whackers . Take the muffler off get it to run if it runs fine then soak the muffler in a solvent for a while to get rid of the gunk in it. This is coused by not getting the muffler hot enough, you got to run those things wide open to keep them from gumming up.
Even if this is not the problem it is good advice.;)

speedy
04-19-2006, 08:34 AM
Blocked/obstructed fuel vent?

Ken

CompositeEngr
04-19-2006, 03:52 PM
so, being a redneck mekanik...
after checking all the stuff mentioned above, I half-choked it and ran it with the throttle wide open for a little bit.
It runs a lot better now, with the choke off. It starts a little hard.

I'll have to look into the carb a little more before I go taking it apart