Two stroke engine...leaf blower help
 

I've got a Stihl leaf blower that runs like crap. The dealer says it's fine...but it isn't. Coming off idle to spin up the throttle it'll bog down and frequently stall. When I do get it running it'll often run low on power. I've replaced the plug and fuel filter...no joy. Any ideas gang?

TIA

Sounds lean. Maybe restricted carb jet. Could also be a weak ignition coil.

Most likely the carb is partially plugged up. Since the introduction of ethanol in gasoline I've had constant problems keeping 2 cycle engines running. Carbs gummed up, fuel lines disintegrating, etc. Using fuel stabilizer helps and I try to keep fresh gas in them. Just last week I had to take apart and clean out the carb on my Honda push mower - very hard to start and no power. Running perfect now.

As Jack suggested, probably gummed up from our wonderful gasoline. I found that I had to run all my 2 stroke engines at least weekly and that included weed eaters, giant R/C race cars, edger skate board and any others or they would never run right. I finally would drain and flush the ones not used such as the trimmers and that cured the problem. I found that in a couple cases the fuel lines actually collapsed from gasoline chemicals and there would be no flow so I'd replace them.

I had the same problem with my Stihl. The only thing that will solve it is to install a new carb. You can purchase a carb kit but, you will never get it to run correctly with the kits because there is a real thin plastic sheet that I believe is part of the reed operation and they never work. I am currently on my 3rd new carb as if you leave the crappy gas sit in them for too long you will have problems. Also the carbs are cheap as they are made in Asia and are junky. Also, you should state the model you have as there are many and many are different.

I couldn't help it. every time someone says leaf blower I think of this pic http://forums.pelicanparts.com/uploa...1416174171.jpg

Does it have a small plastic/rubber fuel primer? If it does check it to see if it's cracked. It will suck air if it is cracked and cause the engine to run lean.

Definitely running lean on low speed circuit. Check for adequate fuel delivery first (as said above) then try this trick. With air filter off, full throttle and RPM's quickly cover the throat of the carb with your palm until it almost quits. It may take a few repeat attempts but it works frequently enough and takes little effort. By doing this it creates an incredible suction on the fuel jets and emulsion tube and will sometimes pull the debris / gum through.

If this does not work, locate the low speed mixture adjustment screw (it should have one) turn the screw clockwise and count the number of turn until lightly seated. Remember this number. Now screw counter-clockwise until the screw / spring comes out. Take an aerosol can of carb cleaner / gum cutter, attach the little red spray tube and spray liberally into the hole where the screw was. Then blow through it lightly with shop air. Re-insert the screw and spring turning clock-wise until it seats. Then remembering the amount of turns prior, go counter clock-wise. This should do it. If not you'll need to remove the carb assy, disassemble to clean.

I keep a stock of those, plus gas lines, etc. for all the 2 stroke stuff.

I also blow compressed air at low volume through the carbs when they run rough. Next week is my big winterize the equipment weekend.

I have also moved to electric blowers for most of the barn work. The new battery powered stuff is incredible. I only have one gas powered blower now.

Thanks guys. this gives me lots to work with.

And of course, be sure your fuel/oil mixture is correct....and spend a few extra bucks to only mix with non-ethanol gas. My Stihl chainsaw and blower are the same if I'm not careful mixing the gas.

Also, check the carbon build-up in the exhaust port & muffler.
Scrape w/wooden stick, etc.
I usually take out that muffler screen and leave it out.

As already stated these carbs always get gummed up. I found that if I use Start your Engines additive it usually clears the problem up. You can get it at the parts store easiest way to go and as I said it works 99% of the time.
http://www.lowes.com/pd_386609-74483-21205_0__?productId=3624074

does this have a walbro carb with a low speed mixture screw?

Easy rick...lets sick him on the easy stuff before we start fiddling with mixtures ;)

+1

take out the spark arrestor.

Good advise Don. I recently bought a like new John Deere weedeater at a garage sale for $10 thinking the typical fuel issues......After a bit of fussing, I removed the screen over the exhaust port (spark arrestor).......Runs like new...

check the muffler for blockage.

i had a john deer that was sluggish when new. i ran it like that for a long time. even tried adjusting the carb but they had these plastic things on there that limited the adjustment. well those had to go. it was running waaay too rich. it also gummed up the muffler. cleaned it, leaned it and it runs like a scalded dog. had it for 10-15 yrs now.

this crappy gas has not been good for it.

"this crappy gas has not been good for it."
~~~~~~~~~~~
For sure!
Also, when done with the rig, pour all gas/mixture out then run it dry.
When I had my service business, I'd buy 20 -30 tank fuel lines and filters.
We changed them annually (around Christmas when work was slow) - also, a new in-tank fuel filter at the tank end of the fuel hose.
'Had to give the good employees something to do.
This gas would turn those fuel lines to mush eventually - they'd either collapse or incur holes.
Preventive maintenance to avoid work-stoppage in the field.
.
One more: keep the carb butterfly shaft clean of micro-junk. We just shot them with carb cleaner now/then.
The dust (micro-junk) will eventually wear on that shaft and it'll suck air.
Cleaning filter goes w/o saying.
.
Happy Smokin'. ;)
.
PS One year I cut the toe off old white socks then slid them over a few of the carbs, poked a hole for the throttle cable, then saturated the sock with WD-40.
They stayed remarkably clean.

Ok required reading.

http://wem.walbro.com/distributors/servicemanuals/WTseries.pdf

Walbro is very open with their tech info.