OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Question On Scott Bonnar Cylinder Mowers Hi I'm Restoring Scott Bonnar Lawn King

I don't understand what this metal rod is. Can you post a picture of it please? I can't even find a clutch housing - the whole clutch is in the open air, and rotates with the output shaft. Of course the clutch has to be removed from the crankshaft extension (what Briggs & Stratton call the "Power Take Off", and I call the output shaft) before the timing cover can be slid down the shaft and removed. Do you mean how do you remove the clutch from the engine's output shaft?

im talking about the metal rod in these pictures, the timimg cover wont slide off the shaft, is there some sort of locking pin holding it on

The only thing I can see that the timing cover has to slide over is the output shaft: you've removed the clutch. The output shaft is the seven-eighths inch diameter shaft with a keyway, sticking a couple of inches out of the timing cover.
Your 60102 has a dipstick, where mine has a level plug (mine's ten years older than yours). You may need to remove the dipstick to remove the timing cover. I don't recall there being any dowel on the timing cover - if there were, you'd need to slide it very straight and square for the first quarter of an inch, to slide it off the dowel. I also may be missing something here - I've never dismantled that part of mine, and the overhaul manual treats it as trivially easy, just saying 'remove the crankcase cover' every time it comes up. What are the symptoms of it not coming off? Will it rotate around the output shaft?

i will have to have another go at getting this cover of, very likely the seals have seized around the shaft if it is a trivial removal.

also theres no dipstick, its a screw in plug and the engine was built in 1974

First, can you rotate the cover, and if so, does the crankshaft rotate when you do? If so, the crankshaft is frozen to the seal or the cover. Was the engine capable of rotating before you started dismantling the mower?
Second, you gave the engine manufacturing code earlier, so I knew it was 1974. My similar engine (60102) was made in 1963. That engine model has been around a while.

circlip behind crankshart seal? regards steve...

I have attached a blow-up of the seal area on this SB. There is something on the crankshaft that could be a circlip on the picture. The reason I didn't think it was one was that I looked at that part of my own 60102 and it looks like a complete circle: I can't see the break that there has be in a circlip. However I admit I can't see mine very well, because there is a blade plate cover of about 15" diameter right up against it.
So, is there a circlip on the crankshaft, adjacent to that seal? If you aren't sure, can we have a couple of closeups please (like the one attached but showing more detail, and showing all the way around the circumference).

im pretty sure that its a complete circle, but ill clean it up a bit and take some close ups, soak it in CRC and hope for the best

The equivalent feature on my older 60102 looks to have a square cross section instead of round. What we need to know is whether the seal lip sits below it, on the smaller diameter of the outside of the shaft. If so, it seems like there is no way the cover can come off without removing it. Surely there is an expanded picture of the thing in the parts list, or someone has experience of pulling timing covers off 60102 engines? If we know it is sitting in a circlip groove in the shaft and it has to come off, we can find a way. However what we don't want to do, is damage the seal but end up not getting it apart.

Hi Tezza, You said in one of your early posts that it was running OK, why are you pulling the engine apart?
Have you got an Illustrated parts list for it?

it runs sort of ok, but since im restoring the rest of the mower the engine gets a good seeing to as well. got my subscription to the parts list monday, need to wait until the paypal funds clear.

Ok i got the cover off, was a simple matter int the end, soaked the seal in CRC and scrubed around it with a tooth brush then slowly jiggled it off the shaft. Only thing left to do on the engine is to polish up the valve and the port. then back to gether, hopefully this weekend ill be mowing a cricket pitch in the back yard

So there was probably a ring of hardened crud in front of the seal, and the rubber part of the seal might have gone hard as well. You will need to clean that area of the crankshaft carefully before you reassemble it. Use of abrasives is problematic, since any grit that gets into the crankcase or is left on the shaft will cause rapid wear. Look for a tiny wear-groove in the crankshaft where the seal lip has been running against it. If the groove is significant, you will need to install the new seal in a slightly different position, so it runs on an unworn part of the shaft.

grumpy,

I would be suggesting that he replace the seal anyway because of the crap on the shaft. Nothing worse than putting it back together and it leaks, better to be safe than sorry.

Bruce, that was just my lousy way of expressing the point. Of course, the old seal was leaking and must be replaced. I suspect it leaked because the dirt that formed that hard ring, found its way under the seal lip. Then it ate the lip, and part of the shaft as well. Seals that wear out due to dirt usually erode the shaft, in my experience. My usual solution is to position the new seal inward or outward slightly, so the lip of the new seal is not running in the groove in the shaft worn by the old seal. In this case there is a step in the shaft right in the crucial area, so there might or might not be enough room to move the seal. The only real alternative, if there is a groove worn in the shaft and you can't move the seal, is to replace the crankshaft.

Hi Grumpy,or mate,you could do what I did, scrap the old Briggs and stick a Honda on it!! Ha Ha

Deejay, I don't think 60102 engines or new parts for them are difficult to get. I'm not even sure they've stopped making the engine itself. As long as tezza98 is intending to do a restoration, not a rescusitation-and-tidy-up, I personally think it needs to end up with a 60102 on it (preferably one as nice as mine, which seems to have run very few hours.) I'm not saying the Honda isn't at least as good an engine, and more modern as well, but it wouldn't be original. I never really approved of the popular practice of putting Chevrolet V8s into XJS Jaguars in place of that appalling Jaguar V12, either. Yes, the Chevvy was a much better engine and made it a much better car, but it ended up a mongrel.

Hi grumpy, it was all tongue-in-cheek mate, I know Tezza is restoring it to its former glory.
But for me, it was a different story, my Briggs was causing me many headaches due to its unreliability, I had spent heaps of hard earned $$$ to try and rectify its probs.
I use the machine regularly, so a Honda was the answer and I've never looked back....Sometimes you have to sacrifice originality for functionality.

the seal is in pretty good condition - looks brand new actually. and I the polished up the shaft with some 2000 grit wet and dry so its smooth as a babys bum.

If it does leak then ill replace the seal np.

Not gonna put a new engine on it unless this one decided to pack it in and then as long os the cylinder block isnt destroyed id buy new parts for it.

The only real issue that i have with the engine is the carby, its a real bitch at the moment, so i gotta give it a good cleanup.

the only other issue i have is the location of the fuel tank relative to the muffler, i think that the tank heats up too much causing vapour lock which may be one of the reasons its stalls after 20 odd minutes. If it continues to do this once i put it back to gether, ill try to modify the muffler to move it completlty away from the tank itself.

First, if you don't have a wear-groove in your crankshaft where the seal lip has been contacting it, that is great. Inspecting an oil seal for wear involves quite high magnification photographs, looking just at the corner of the lip that touches the shaft. I feel confident that yours is worn. The only other common cause of oil seals leaking past the lip is misalignment: either the crankshaft being off-center in the seal, or the crankshaft running out of true. (Of course seals can also leak around the outside, due to a damaged housing bore or seal exterior).
I doubt the heat transfer from muffler to fuel tank will cause vapour lock, unless it is extremely hot - which in turn seems uncommon in Tasmania. Rather than modify your engine, I think you'll get a better result from finding what is wrong with it. Most likely there is a fault in carburetor, ignition, or valve or piston-ring sealing. While you have the engine apart you should attend to all four.