I have the Bolens BL100 with less than 3 hrs use, 2 yrs old, very light trimming needs. EVERY SINCE I BOUGHT IT, I can almost never run it without it on half-choke (start in 1, move to 2 to run). If I move it to 3 (after a minute or two), when I pull the trigger to accelerate the motor, it wants to die unless I "goose" the throttle. Yet when in position 2, while it won't quit, it seems to sputter a bit. Its acted this way since I bought it. I should have returned it, but it was purchased two seasons ago, so I'm out of luck there. Does this sound like an improperly set carb? The only setting documented is the "idle speed" screw. I was thinking it might be running a bit too "rich" or "lean" and there would be a screw to adjust that. Does anyone have experience with this problem and have a solution short of taking it to an "authorized service center"? I can't see spending more than half again on this unit for a single service call.

Rob, May 2008

I love finding solutions like this. Hacks awed the aluminum, backed the screw out 3/4 turn and now runs great. Thanks y'all.

Paul, October 2014

thanks for the hacksaw tip,paid $30 for it at a yard sale, wasn t gonna put any money into it,cheaper than to buy a new one,it runs now, not perfect but runs

ed, July 2014

Thanks for the tip. Ran a hacksaw over the aluminum shroud and adjustment screw. Now I can run in regular position and not half choke. Runs better than ever now, thanks!

David, June 2014

Just did the adjustment and my trimmer runs better than ever! I've tried everything I could think of with no success, this works like a charm!

Thank you guys for posting this!!

Jeff, March 2014

Hint for adjusting those H/L screws: a crimp on wire splice (the larger one-blue) will fit snugly on the recessed screws (the wierd shape half round with flat side) and allow you to adjust them as needed. You can also use other crimp on wire splice fittings (any for 10 guage stranded wire works well) you may have to try different sizes and see what works best. I keep a variety in my tool box for just this purpose.

Poppa J, September 2013

Had the same problems with my Bl100 which had run well for about 4 yrs. The primer bulb was slow to reinflate and when I could get it started, the trimmer would die after about 2 minutes of run time.

Replaced the primer bulb and fuel lines but bulb was still a bit slow to reinflate and the trimmer continued to die after few minutes run time.

Disassembled the carb and found what I thought might be the problem. The tiny spring-loaded hinge that is attached to the fuel inlet needle valve was gummed up with fuel residue and was slowing the lifting of the needle valve and in turn the inflation of the primer bulb each time it was depressed. Cleaning and reinstalling the little hinge assembly solved that problem but the engine stalling issue remained.

As a last resort I completely diassembled the carburetor and carefully cleaned all the components of the unit with a good quality carb cleaner solvent. I also used a high pressure air nozzle to blow out all passageways in the carb body from both directions wherever possible. Before reassembling the unit I also placed the carb body in a small container filled with the solvent and let it soak for approx 24 hours. Following this I used the high pressure air nozzle and blew out all of the internal passageways once again and then completed the reassembly. This seemed to solve all the problems and the trimmer now runs normally with no anaomalies.

alexk, August 2013

Incredible!!! Used the saw to groove the screws and made the adjustments. Works perfect now. Great feed!! Thanks for your help.

Gmccann, June 2013

I just tried this solution and it worked like a champ! Just Andy Jordan said -runs like a chainsaw on steroids!

I did find out that there are a special set of screwdrivers that are needed for adjusting these 2 Cycle engines. Search "2 cycle engine carb screwdriver" and they will come up. I think it is pretty crappy that they make it so you have to get special screwdriver or take it in to have the Mixture adjusted...

Andrew, June 2012

HOORAY...COULDN'T FIGURE THIS DANG THING OUT...REPLACED filter and primer bulb....found the advice about hacksawing the slot...took 3/4 counterclockkwise turn..but now mine is running like a pro chainsaw on steroids..GRRRRRRRRRR...I will probably be able to take out the oak trees i want cut down...HA....funny that they dont leave the slot...and tell you in their manual to start backing out the screw 1/4 turn at a time until it runs...WHY ???...because they want you to decide that it would be easier to just get a new one...I wonder how many " free weed trimmers " repair shops end up with....
hooray for the person that posted it....if you are ever in Bowling Green, KY..I owe you a couple beers....make it 3.....

ANDY JORDAN, April 2012

I had the same stalling problem with my Bolens BL100 and followed the instructions of sawing a slot with a hacksaw down the aluminum fins into the top of the screw. Then backed it off about 1/2 turn with slotted screwdriver. Works great now!

Bob, October 2011

Hey, Happy Bolens Owner, thanks for the tip about hacksawing that aluminum shroud around the adjustment screw!

I was at a yard sale this morning and saw this trimmer for only $1 because the guy said it didn't run right. I'd been wanting to mess around with gas trimmers for a while so I bought it. I was having this same problem with it idling fine but not wanting to accelerate at all. I knew I needed to adjust that screw but couldn't figure out how to get to it. I followed your advice and just sawed a slot down to the top of the screw then sawed a couple more passes to make a slot in the top of the screw. I ended up having to back the screw out about 3/4 of a turn to get it running properly but now it runs great.

A $1 trimmer that's nearly new, runs great, and the guy even gave me a spool of the string to go with it!

Phil, July 2010

If you were to remove the back cover to expose the carb, there is a single screw on top with an unusual shaped head. As it turns out, just a few drags of a hacksaw will cut through the aluminum around the screw and score the top. Just a few touches with a dremel cut-off wheel make a nice groove in the unusual screw. Then about 1/4 turn counterclockwise makes the Bolens 100 run very well. I guess the original owner of mine did this.

Happy Bolens owner, August 2009

The mixture is EPA-mandated WAY too lean. I have the same problem on my BL150. The choke being half-on is a cr*ppy way around this problem. I have been trying (without success) to get the thick metal plug off of the mixture screw access. This thing would purr like a kitten if I could only adjust the fuel mixture.
Please email me at telcompro2 (at) AOL if you have figured out how to remove this access plug!

Frank, July 2009

mine flat out doesn't work...i'm researching a probably cause...cant find where to get any parts on it, although i believe that a new coil would be needed, because i'm not getting a spark, i tried jumping (eliminating) the kill switch, as i always choke mine to kill the motor anyways, but reading more and more it may be better to throw it in the trash and start fresh.

Gabe, May 2009

I have had the exact same problem. I don't know if it is the idle screw or not, but either way, it came out of the box that way. Take it back!

JC, April 2009

I have the exact same problem. I have never been able to run it in the 3rd position and now it is stalling even when it is in 2. I came inside with my yard half trimmed because I am so irritated with this trimmer. I am going to buy a new one tomorrow since the problem has only worsened since its purchase two years ago.

Samantha, July 2008

Thanks for the reply. I turned the idle screw higher, and it helps a bit when trying to accelerate the motor from idle. Not perfect, as I'm sure the carb needs adjustment (probably a little too rich as it seems to prefer half choked).

My mistake was not taking it back right away when I purchased it. I thought the engine was new and probably needed to break in a bit. Well, even though it has a 2 yr "warranty", I was curtly told it does not cover "tune ups" and therefore they would need to replace the carburator and cost is $130. Since the trimmer only cost $70, he said just throw it away and buy a new one. He said he would not work on the carb because of government would fine him $50,000. This was the local "repair facility" that the Bolens website directed me to.

I was told if I had taken the unit in within 30 days of purchase, it would have been replaced. He didn't say whether it would have been a repaired model or new.

So much for a "2 yr warranty" since the fact it always stalls when trying to accelate is a "tune up" problem even though it came out of the box that way.

So I'm writing this to help others. If you get one that is not perfect, take it back immediately. Don't think the engine just needs to get broken in or it will smooth out after a few tries. TAKE IT BACK RIGHT AWAY.

Thanks for the help.

Rob, May 2008

I think the idle mixture is too lean - try undoing the idle screw a 1/4 turn at a time to see if the condition improves.

John, May 2008