For the most part I love my Lawnboy Duraforce, but it has started this really obnoxious squeeking when I let off the throttle handle and the blade brake engages. Is this a concern, or is there a solution for this?? I do not like a lot of noise like this on my motorized machinery, it makes me nervous that there is some other issue involved.
Lawnboy blade brake
- Thread starter lobo11
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That's the nature of the beast. I have two of them, and they both do it. I know some people have this tendency to ease off the bail when they stop it, but you're better off just letting go of it. I had to school my aunt on doing this, as the brake was trying to stop the flywheel while the engine was still running. It's a crude design, and the brake engages slighly before the switch kills the spark. With the power the DF engine has, it'll just pull harder against the brake band.
I'm afraid this is something you're just going to have to live with. I have yet to see a brake band fail on a DF even with the horrific noise they make when you shut them off.
I'm afraid this is something you're just going to have to live with. I have yet to see a brake band fail on a DF even with the horrific noise they make when you shut them off.
Thanks. I was sure there were other DF users out there, but I was starting to wonder.
I've owned and worked on Lawn-Boys since I was old enough to pull one over with my own strength. The DF engine is an engineering marvel, IMHO. 6.5 HP (and gobs of torque!!) out of an engine that's only one cubic inch larger than the 4 HP F-series that it replaced, and it's cleaner running and uses less fuel too!
I'm still somewhat partial to the old D-400 and D-600 engines on the '60s and '70s machines, but for everyday use, the DuraForce can't be beat.
The M-series Lawn-Boy from back in the early 90s was quite the machine in its day...Piston ported engine with optional oil injection, a first on a walk-behind mower, and many other advanced features. Problem was it didn't look or sound like a "real" Lawn-Boy. It was heavy and cumbersome, and extremely expensive to fix. I had one, and traded it on my 10525 with the DuraForce engine. Best move I ever made. I actually made money on that deal, getting $120 more than I paid for the M21ZMR on trade!
The V-series engine that came out just before the DF was another odd duck. I have two of them sitting in the back shop doing nothing right now. I have no idea what I'm going to do with them...They were rescued off the curb on garbage day, so the price was right! I've never even tried to start either one, so I don't know what I'm in for once I tear into them.
I'm still somewhat partial to the old D-400 and D-600 engines on the '60s and '70s machines, but for everyday use, the DuraForce can't be beat.
The M-series Lawn-Boy from back in the early 90s was quite the machine in its day...Piston ported engine with optional oil injection, a first on a walk-behind mower, and many other advanced features. Problem was it didn't look or sound like a "real" Lawn-Boy. It was heavy and cumbersome, and extremely expensive to fix. I had one, and traded it on my 10525 with the DuraForce engine. Best move I ever made. I actually made money on that deal, getting $120 more than I paid for the M21ZMR on trade!
The V-series engine that came out just before the DF was another odd duck. I have two of them sitting in the back shop doing nothing right now. I have no idea what I'm going to do with them...They were rescued off the curb on garbage day, so the price was right! I've never even tried to start either one, so I don't know what I'm in for once I tear into them.
Not sure about the Lawnboy...but on my Snapper I tape the safety bar up and shut it off by using a screwdriver to short the spark and stop the engine.
They put retarded dead man's bars on the handlebars so that if you lose your grip it shuts down the mower and brakes the engine.
I guess they feel peeps are not smart enough to mow without them anymore. To me keeping the bar depressed against the handlebar is a royal PITA.
On my Duraforce I can ease the brake bail up until the ignition cuts the spark and the engine coasts to a stop without the brake activating. I'm with GT on the Duraforce being the best engine that Lawn Boy ever built, gobs of power and torque and they will burbble like the lawn boys of the past if you rejet them.
Al, I use a small spring clamp to keep the bail depressed so I don't have to hold on to it. Others use a short piece of PVC pipe that they have cut a slot in to pass the bail then rotate it to lock it down.
I use Mobil 1 Racing 2T oil at 32 to 1 with 87 octane gas and stabil to keep it fresh.
Al, I use a small spring clamp to keep the bail depressed so I don't have to hold on to it. Others use a short piece of PVC pipe that they have cut a slot in to pass the bail then rotate it to lock it down.
I use Mobil 1 Racing 2T oil at 32 to 1 with 87 octane gas and stabil to keep it fresh.
Thanks guys.
I guess that they trust us a little more with mowers down here, as I've never heard or seen of such a thing.
(Until recently, you could buy "utility" mowers with a removable section of casing that allowed you to ringbark trees...well get close to edges).
I guess that they trust us a little more with mowers down here, as I've never heard or seen of such a thing.
(Until recently, you could buy "utility" mowers with a removable section of casing that allowed you to ringbark trees...well get close to edges).
I like the PVC idea.
mtgrs737-Thanks for the tip on the ease-up, it worked like a charm.
I've always just lifted the saftey handle enough to cut spark to prevent wear on the brake. Not sure if blade brake wear is really much of issue, but I want to this mower to last as long as I do. I could never go back to a pansy 4-stroke.
I tried adjusting the DuraForce kill switch to kill the spark before the blade brake engaged, but there's not a whole lot of adjustment there. Best I could do is get the brake to engage at exactly the same time as the spark gets killed. I tried going further, but it wouldn't give me spark when the bail was pulled back. Maybe with a little more dinking around with it, I could get it just right, but it does not bother me...I've never had a blade brake problem with one of these, or any L-B for that matter.
Some folks say that the upward presure on the bottom of the flywheel/fan might over time cause wear on the tapered mounting area of the crankshaft/flywheel. Personaly I just coast it down to a stop before I let the brake touch the flywheel. I've seen mowers with the brake pad area cut off so that it cannot brake at all, seems a bit extreme to me though. I've never heard of a flywheel worn out because of the brake.
On the V-series engines (the predecessor to the DuraForce), the blade brake puts enough pressure on the main bearings that the crankshaft makes an audible "clunk" when the bail is compressed against the handle releasing the brake pressure! There's got to be at least 1/8" of end play on the crankshafts on these engines, but it doesn't seem to bother them. More than one person has commented about this, so I'm going to consider it normal. Both my V-series mowers do it, and they still run like Swiss watches.
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