Won't start.
Problem is sheared flywheel dog. Poor design by MTD/Bolens makes consumer purchase a $30 flywheel rather than a $0.25 key to fix. They designed a key(dog) into the aluminum flywheel rather than cutting a keyway into it.

L.P., March 2007

Throw it in the garbage and go buy an Echo. These weed eaters suck! Horrible design through and through. I think MTD needs to get their shit together. I will never be purchasing another mtd product.....EVER! Salvaging the good motor and selling it to an rc car hobbyist to put in their model car. Lol complete waste of money, MTD.

Paul, November 2013

Same problem here. Has spark, fuel and good compression. Disassmbled case and found timing about 130 degrees off. Removed flywheel and found broken key on the flywheel.

p, July 2012

i've never started a weedeater before and thr instructions are half there missing 1-8 it's a bolens mtd bl100 17"cut 31cc

christina, September 2010

I had the same problem. Wouldn't start even though it had spark and fuel and compression. Turned out that the flywheel key had sheared. Spent $30 for a new flywheel and back and running good.

Neil, October 2009

I have a bolens bl 100 trimmer. I caught the string in the electrical line to my malibu lights. Since, have not been able to start it. Everytime, i pull the rope the head turns at the same time.

Does this mean that I have to replace clutch or something else?

Help!

Debbie, May 2009

the bigest pile of cr*p i have bought i bought there mower and weed wacker and they both broke after using them 4 times

pissed off customer, February 2009

Bolens BL100, Had the same problem. Changed fuel, plug, carb (from an older model that was working), Coil assy. and primer bulb from same Working unit. Not a pop to be had but much cussing and about six hours work. Put a screw driver into the plug hole and slowly turned the shaft to determine top dead center and checked the flywheel magnet location-they were about 180deg. from the coil. Not good. Pulled the fly wheel off; not easy when the shaft just turns inside the fly wheel and the nut won't come loose. I took the muffler off and put a piece of fairly hard wood into the exhaust port above the piston to stop the shaft from turning and got the nut off. The molded in "key" on the fly wheel that is suposed engage the slot in the shaft was flattened and not engaging the slot. It did not look like it was sheared off; it was flattened and spread out to both sides. I think it happened during assembly. When the flywheel was put on, the key did not hit the slot but the operater drove the shaft nut home with an air wrench.
I very carefully Filed a 1/8th in. wide slot centerd on the key location about 1/16th in. deep; Filed a 1/8th thick key and put it togethr the old fashioned way. Not too hard to do if your half nuts.
Three pushes to the primer; second pull on choke; it fired and ran;Scared the #*&+ out of me after nothing happening for three days off and on.
Good luck

Philip johnson, April 2007