The crank is supported by large ball-bearings. I doubt if it has too much clearance although it's not impossible. All ball/roller-bearing engines must have clearance.
Oil film under air cleaner: meaningless unless it continues to build up while running. Usually it only means fuel leaked into the carb and ran out of the filter.

Crankshaft seals: the engine won't run well enough to cut grass if one or both seals do not hold crankcase compression. A 2-cycle is 'self-supercharging' which is how it manages to run. The seals must hold against vacuum when the piston goes up, drawing air/fuel/oil through the reed valve, then against compression as the piston comes down, compressing the mixture against the closed reed valve, forcing it into the cylinder.

Sounds to me like you just need to use the mower and perform the usual maintenance. When pulling the starter cord you'll hear a clanking sound, too, which is also normal. The key here is the mower works. For $75, I would just use it as long as possible.

izzat so? It is normal for Lawnboy engines to have that much "slop" on the bottom bearing? It seemed to me that the shaft just above the blade was coated in oil as well, and the belt and drive pulley. I don't mind running this for awhile in this condition ( if it is a condition at all), but I don't want to hasten its demise. I don't mind rebuilding it, if it is cost effective. Or it is better to rebuild a "classic" Lawnboy rather than a late production Toro restrike?

Rick

Where you stop in the rebuilding process is up to you. You'll have to assess the condition of the cylinder which is key because if it's scored bad just get a short block. Yes, you can replace the bottom bearing and no it should not have any obvious side play at all in that lower bearing. Replace the crank seals while you're at it. To me if the cylinder is good it would be worth it to replace the lower crank bearing, piston, rings, and seals.

Okay, new information provided - oil on crankshaft. Indicates lower seal leaking. Since it still runs, it may be related to the oil on the deck. If the inlet valve in the carb lets too much fuel in, particularly with the engine off, the raw fuel/oil can get out at the lower seal (and back through the carb). You'll have to raise the engine to see if the lower seal has popped out. The seals on the Duraforce were designed to prevent this but it's not unheard-of. You may have to take the carb off and clean it, possibly adjusting/replacing the float and needle and seat.
On the crank play, if you're getting .05" at the end of the blade, I wouldn't be too concerned. If I saw this on a 4-cycle with sleeve bearings it would be a problem. Every LB I've ever seen had vertical and side play in the crank.
With a cold engine, will it start without choke or primer? Does it smoke excessively when warmed up? These indicate it's running on too much fuel.

My 10323 when I grab the blade is tight with no play and it should as it is still fairly new.My 1973 has definite play, lower seal, but still runs and starts good.It's a good idea to install a gas shut- off valve because of the cork float in the carb. and the fact that if you tip the mower on it's right side it will flood saturating the air filter with gas and making quite a mess.

saxman & rday

I'll give her a pull tonite without priming and see if it will start. It seemed to me that it did not smoke once it warmed up. As for the crank play, it's way more than .050 at the end of the blade- that's what my brain calculates it to be at the bearing 10.5" away. I may be in this eventually for a short block, which I have seen for less now, like $175, but I'd like to try it a la carte, if I can.

Can I tell if the crank is bent if there is play in the bearing? Are the bearings so specialized that I can't find them from a bearing house?

I just wouldn't put that kind of money in a heavily-used mower. It might run like it is for years. Try to get a better one next time - they're out there.

Thanks Saxman.

I think I will just run it as is the rest of the year and then take it apart and see if I can just get that lower bearing and seals. I'll know what to look for next time. Meanwhile, I have 3 semi-functional mowers....

I don't think the price of a shortblock ($175) is that much. When you are done you basically have a new mower, IMO. There's really not all that much more to wear out on one of these, is there?

Rick

There's really not all that much more to wear out on one of these, is there?
Famous last words...If your going to put that much into rebuilding you could just hold out til the end of the year, sell all 3 and take the $175 plus what ever you make on the other 3 and buy a new one...

FYI if you are still running this mower, I went to a bearing supply house near me, bought the bearings for 8.00 a piece, and pressed them onto the shaft using the case as a rough guide. It did make the crankshaft a bit tighter but not much. I doubt that bearing has as much play as you think it does. A full duraforce rebuild at $100 is tough but it can be done!

Kyle

Hawk - I'm listening. Can you give us some info on those bearings? Mfg and #? I've never seen the bearings listed as a part seperate from the "crank assembly". I think Toro want's to line their pockets by selling another "assembly".
Thanks.

The guy at the bearing house measured the bearing with a caliper and had 2 in stock. Open your yellow pages, and stop by some of these places with the bearing off of the crank shaft, they should be able to help. Also you may want to use a feeler gauge to measure the space between the bearing and the crank, given that it does not get pressed flat or all the way down,

You can also do as I did and use the case to help you press it on in the correct position.

Mine works great and saved me a ton of money let us know how it turns out.

Kyle

Ball bearing crankshaft bearings are common sizes. I have always bought bearings for 2-cycle crankshafts at bearing stores. Even Japanese 2 cycle motorcycle engines use common size ball bearings on the crankshafts.

I'll give the bearing house a whirl this Spring when I start my next project, the 10324. Thanks!

first of all there should be NO movement when you grab the crank anyone that say's different should take up collecting stamps because they have no idea what they are taking about.as far as the dura force engine when you have the engine off of the mower deck take out the crank seal on the blade side off and see what kind of movement you have if you see the inner race of the crank bearing move then the problem is the bearing spun in the case and now you have play the older LB had a tab on the bearings to keep them from moving the duraforce does not.i worked on about six so far and everyone of them spun the bearing.