BOB-CAT by Ransomes, self propelled!

[combatcarl]

:drink:So about a week ago, I saw what appeared to be a mower with a cast aluminum deck, pop up on Craigslist, just south of me. Ad stated it may have a bad head gasket, but ran, and pushed itself, and was otherwise complete. I called, left a message, and then missed his call back. It ended up working out, as I went and picked it up today, and it appears to run and mow just fine. The neatest part is the sticker of where it was bought, business is long gone, but the mower has lived in this area its whole life, and was maintained very well, excepting some surface rust obscuring the engine model/type/code line. STICKER PIC AT BOTTOM.
Without further ado, I present:

It's a keeper, I'm afraid, to The Boss's chagrin, but will prove useful, so I don't feel bad. I had never seen one with a cast aluminum deck, nor could I find any information about them on the interwebs. The only two I could find were both posted/owned by same guy, and he really didn't know much either. Now to give it a full tune-up, and eventually paint! Any body here pick out any identifying features chime in! I couldn't find a model no. on it anywhere, but full daylight inspection may help with that. ENJOY!!!:drink:

 

[combatcarl]

So with some light and a rag, cleaned off a couple stickers, revealing that it is a model M21-4SPZ. B&S 4horse, needs a little carb cleanup, and my phone wouldn't catch it right, but appears to have a "third main bearing" underneath, extra support for blade strikes, etc. I'm glad it self propelled, it weighs about 90+lbs. s

 

[combatcarl]

So it looks much better now, all washed up, needs a blade, and the hub for it, too. Found some, but not under bob-cat results, searched "sensation 21" ",and found a bunch of shared parts...weird. Time for a carb tune/adjustment, but can't find any info. Anyone know where I can find adjustment directions for a b&s 395957 carb? Or am I stuck buying a new one? This one works just fine, only idles at 3/4 throttle, though, revs up and runs fine, otherwise. Got to hammer back and weld up a rock ding in the deck, too!

 

[combatcarl]

Never mind! Found it! Spent all afternoon on my phone, hunting through every carb rebuild search I ever did, and lucked out!
Disassembly, Cleaning and Repair of Briggs and Stratton Tank-mounted Vacu-jet Automatic Choke All-temperature Carburetor - Vertical Crankshaft Engine
I'll let y'all know if this helps, it should, they cover about every carb out there.

 

[combatcarl]

So haven't done much, except clean her up, and oil change & spark plug. Runs better every time, but should do a carb refresh soon. Needs a blade and hub as soon as possible, still haven't gotten that far yet. Heckuva machine, tho.

 

[TheCaffeinatedOne]

Look familiar? I'm about to tear into this old warrior - everything is there, but can anyone tell me more about the dual shaft Briggs motors? This has a horizontal power take off shaft just above the deck, coming out of the aluminum crankcase, that powers the drive contraption. I've never seen this before and would like to know what I'm getting into before I break it...

I think this was from the late 1970s - perhaps early 80s. It belonged to my late father in law, who was as crusty and frugal as they come, but who also knew his industrial equipment. He would opt for simple, unadorned and high quality every time.

 

[combatcarl]

On the blower shroud, just above the spark plug should be a string of numbers, right below a Model/Type/Code. That'll give you what your engine is, and start you on track for parts. That's an *** kicker of a mower. I love mine. Heavy, but nice. http://outdoorpowerinfo.com/repairs/briggs_stratton_carburetor_cleaning_repair.asp
That'll more than likely have your carb rebuild for ya. Most engine parts are very available thru eBay or other engine cannibalism. I've yet to see if my local bob cat dealer has any drive or deck related parts.

 

[combatcarl]

Oh, and seeing as how it doesn't have a dead-man safety on it, it's at least 82 or earlier. The first four places in the code section of serial is the last two digits of year, and two digit month of engine manufacture, respectively.

 

[TheCaffeinatedOne]

Thanks!!

That'll get me started...

I'm inclined to rebuild rather than replace if I can do it sensibly - I expect this motor is as beefy as B&S made and worth the effort.

 

[combatcarl]

How she sits now...

And hard at work. New blade time already.