Dura Force Block Damage...salvageable?

[ltbnkc]

Picked up a damaged 10252 Dura Force, crank had been bent and eventually broke in half at the cam lobe. Tore it apart and found some grooving in the block above the retaining ring. Doesn't appear to be affecting the bearing or have gotten into the piston wall, but there are a couple of burrs that will need to be filed off. I have sourced a crankshaft for it and would like to salvage as much of the motor as I can. Anybody have an opinion on whether I can get any more life out of this block? Parts probably will set me back $60, whereas I have found somebody selling unused shortblock assemblies for $115 shipped. I realize there are more cost effective, shorter paths to getting a mower, but I am trying to keep this one out of the landfill and would like to reuse as much of the original as possible. This is my first Lawn Boy and I must admit, the 2 stroke bug is a contagious one! Thanks for the help.

 

[mechanic mark]

Take your time weighing options, your decision, let us know what goes, thanks. Where would my money be best spent, invested, is it worth the gamble? If you think it is, go for it.

 

[jp1961]

Whew, tough call. Take your time before spending any more money on it like Mechanic Mark said. DuraForce Lawn-Boys are pretty easy to come across on Craigslist (at least in Michigan), it might make more sense (cents,,,lol) to buy another one.

Jeff

 

[motoman]

Do penetrant inspection for cracks. Magnaflux iron/steel. Zyglo black light the aluminum. Otherwise you are guessing. You cannot do a good enough visual after the damage done. The mag should be available locally. You can buy kits for the Zyglo or perhaps aircraft engine shop which could really be expensive. IMO

 

[Phototone]

You could just source another salvage mower with a unbent crankshaft for much less than $100. Many times people discard these mowers for what are actually trivial reasons, such as a bad ignition coil (a known failure point on DuraForce), or they left it out in the weather and the reeds rusted, thus not sealing, or the carb is full of crud. Simple fixes, and the basic block and piston and crankshaft are usually OK.

 

[d_sharier]

If you have already made the decision that you are going to repair this mower my advice would be to buy and install a NOS shortblock. Aside from any unseen damage resulting from the catastrophic failure, heat and friction have already started to take its toll on the cylinder walls. (evident in the pictures) There is something to be said about taking a step back and looking at a finished project. That "warm and fuzzy feeling" is why most of us do this. I imagine that is why you are this far into your DuraForce. In all reality, even after buying a NOS shortblock and the other ancillary parts you need, the total investment will still be less than buying a new mower. As long as you don't count your time anyway! LOL. Most of us gave up on vested time long ago!! LOL

Here is how this plays out in my head: Motoman is right about how to appropriately check the integrity of the cylinder/block. The problem is that unless you are planning to do a ton of these, the initial investment outweighs the benefit. Especially when considering the cost of a new shortblock. Now when the time comes that those blocks are added to the NLA list, the story may change. That being said, lets say you do a visual inspection and decide to use it. Clean it up, rebuild it with a new crank, conn rod, etc. ect. etc.. Get it all squared away, pull the cord and realize very quickly that something was missed, Back to square one- out time and money. OR.... get it back together, pull the cord and it fires up and runs great. For the next few mows anyway, because it low on compression from age and use. In a week or two you may be at square one again, needing a rebuild. Or... It works great for the next 20 years. All of those are possible. For myself, I like to remove any and all possible "what ifs" from the equation. I know that buying a new shortblock puts me in a far better standing from the start. New parts SHOULD give the desired results. That "warm and fuzzy feeling" turns into "rage and frustration" very quickly when I finish a project and realize I should have listen to that little voice in my head telling me not to cut corners.

Lastly, if you plan on keeping this mower, then a new shortblock will give you the satisfaction of completing a repair. It will also leaving you with a mower that should give you years of reliable service. (as long as you maintain it properly and swallow the fact that these mowers like new ignition coils, crank seals, and carb needles)

Thats just my opinon- take what you like and leave the rest

Let us know how it turns out. Don't be afraid to ask questions too! There is a ton of information out there and many of us are willing to share it, so just ask. Good luck and have fun!!!

 

[motoman]

I'll just add that magnaflux is widely used and not so expensive ( I think). The aluminum crack checking "could" be done at home . Couple years back I did find a kit that included degreaser, dye and developer. Once prepared the part is placed under a "black lite." I think this is ultra violet. We just bought a little Chinese flashlite with ultra violet to look for cat pee on our rug-$20. I think the Zyglo kit was about $35-$50 a few years ago. But good used or new piece parts are a better bet, and what if your parts fail crack test?

 

[lewb]

With out question if you are going to try and run same mower get a short block, will be money ahead. I did this with a 10547, now I have the best mower I have ever owned.

 

[ltbnkc]

I appreciate the feedback on my short block quandary. I was on the fence like several of you. I also see the folly in trying to nurse broken parts back to life, only to be let down when it breaks again. However, I looked at this mower as a learning experience, having never torn a small engine apart.(My old MTD Lawn Machine, a hand me down from my father in law when I bought my first house, gave me 13 years, with the only wrench ever applied to it being a carb cleaning one season, and the thing still mowed when I sat it on the curb the day I moved out!) Right now pennies are a touch tight and I already had too much money sunk into this thing, having made a costly mistake not looking it over closely enough when I bought it. I'm pretty sure the shaft was bent then. Like I said, this thing was a learning experience. Colleges aren't the only places to pay for an education! I decided to be a cheap bast@rd, and see if I could get some life out of the old crank case. I sourced a $22 crankshaft on FleaBay and bought a new needle bearing and oil seals as well. Put her back together and she runs well, for now! I had to clean the carburetor 3 times, after the first 2 attempts yielded in a stalling issue. It's amazing how these little carburetors stay functioning in the filthy environment we subject them too. I just knew the first time I had it clean enough, but young grasshopper learns slowly and neglects to remove all 3 jets and blast them out.....oh and blast out the primer tube for good measure! I would like to get a little use out of this thing before it craps out again, but if it does, so be it...I have enjoyed the learning and will tear it down again and put it back together...next time a little faster.....I have been away from lawn mowing for a couple of years and really hated to get back into it, but this little Lawn Boy journey has been fun and I really enjoy the enthusiastic community of Lawn Boy owners out there trying to keep the 2 strokes alive. I'm already watching craigslist for my parts donor machine.....Lawn Boys are like puppies, hard to not take em home!

 

[reynoldston]

You are doing this for a learning experience. If you took a coarse at a school what would it cost you. So even if you spent a couple of hundred dollars that isn't that much. Parts are $$$ and its nothing to spend that kind of money in a repair job to do the job right. I can see your very first lesson is buying parts and what it cost. I hope you the best of luck on this. :thumbsup: