old, 3.5 hp Briggs Stratton lawnmower remove flywheel?

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  #1  
Old 03-07-08, 01:24 PM
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old, 3.5 hp Briggs Stratton lawnmower remove flywheel?

I've got an old lawnmower, vertical shaft, B&S 3.5hp engine that won't start, no spark. Been a while since used, but fuel was drained entirely before storing.

I've got the cover off, shroud, recoil start, etc., but there's still the ratcheting mechanism on top of the flywheel. Isn't there something, a nut or bolt that holds the flywheel on/tight, or can I just put my puller on the ratcheting thing and pull the flywheel off?

I'm new at this, but mechanically inclined, so the more detail the better.

Thanks!
 
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  #2  
Old 03-07-08, 02:08 PM
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Copy down the model, type and code imprinted just above the plug on the top shroud.
Enter model and type at following site to download pdf IPL for engine.
https://www.briggsandstratton.com/ma...nav3&subMenu=3
You can see the starter clutch assy. Pull off the square stock and remove balls, the next part the balls rested in has to be unscrewed. If you're real careful it can be tapped off, but there is a special that should be used.
 
  #3  
Old 03-07-08, 02:41 PM
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I always used to just use a pipe wrench to loosen the clutch (without disassembling it!) You put the pipe wrench on the lower part of the clutch (around the part that has the 4 holes tapped in it) because it is like the nut that holds the flywheel down. Once it has been removed, you'll put the puller on the flywheel and pull it off. Usually you can tighten the puller snug and give it a light rap with a hammer and it will pop the flywheel off. A mower that's been left to the elements might be a little more difficult to work on.

I'm guessing you probably just need new points and condenser. Might also be a sheared flywheel key. Been a few years since I worked on those old engines.
 
  #4  
Old 03-07-08, 02:58 PM
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Ok, got the manual, very helpful, thanks.

I don't see any tapped holes in the clutch, but I could put a pipe wrench down on the casting under the round part.

Is it right hand thread, so turn counter clockwise to loosen?

Hmm, no way to attach the photo I just took. Try this link, I'm new at sharing photos via photobucket.

http://s265.photobucket.com/albums/i...ower%20engine/
 
  #5  
Old 03-07-08, 03:26 PM
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The trick is to remove the part with the 3 ears on it w/o breaking off any of the ears. It unscrews CCW. Remove the little cover plate, the square thing and the balls first. I've got both the tools needed. one to hold flywheel steady and the other that fits over the 3 ears to unscrew.
Posting all the model, type and code nums will be helpful.
 
  #6  
Old 03-07-08, 03:29 PM
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looks like yours has only 2 nubs with tapped holes. I usually put the pipe wrench around those nubs where the 2 holes are, (unfortunately I never had any of the fancy tools) and tried to be very careful not to crush or bend them. I can't recall ever having broken one off before. They usually turn off fairly easily... counterclockwise, if I recall correctly.

Be sure the spark plug is disconnected as you do this.
 
  #7  
Old 03-07-08, 04:19 PM
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Model
92502

Type
0865-01

Code
74052429

Does the above tell how old this really is?
 
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Old 03-07-08, 04:26 PM
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92000's are probably from the 1970's. They're the kind I used to work on when I was a bit younger.
 
  #9  
Old 03-07-08, 04:27 PM
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that ratchet thing is part of the rope starter. don't strip it when taking it off or you won't be able to start the mower.
 
  #10  
Old 03-07-08, 05:27 PM
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Originally Posted by rernst View Post
Model
92502

Type
0865-01

Code
74052429

Does the above tell how old this really is?
The 1st 2 digits of the code is yr, then mmdd, of assy.
It will have points and condenser.
 
  #11  
Old 03-07-08, 05:46 PM
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ah, interesting, 1974, wow, over 30 years old and still running.

Thanks all, I got the ratchet mechanism off using the pipe wrench suggestion, worked great. the seal or cover for the ratchet mechanism came off, so I saved all the parts for re-assembly. Should there be any type of lube in there, or just clean the "nut" out carefully and put the ball bearings back in correct place? I found it very interesting how it was made/works.

It'd be neat if there was an adapter for a drill that would fit the top of the ratcheting mechanism (like the female part on the rope pull part, but not plastic), so you could just use a drill to start the engine.

now to find my puller and get the flywheel off, maybe tomorrow. Looks like it's threaded for a standard pulley puller.

I've heard there's a generic electronic replacement for the points for about $10-11. Can I purchase that somewhere local (I'm in San Diego, CA), or do I get it via the internet? Is there just one type, and is there a specific name I should be looking for? obviously I don't want to spend a bunch on something this old.
 
  #12  
Old 03-07-08, 07:56 PM
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If it were mine, I'd forget about pulling the flywheel and just clip the points wire off and install a newer coil. The newer coils have electronic ignition and don't require flywheel removal. It's a bolt on and go type thing. Stop at any small engine shop and ask for a good used coil for a 3 horse classic briggs, and you should be able to pick one up for 10-15 bucks. A used one should be fine...they rarely fail.
 
  #13  
Old 03-07-08, 08:36 PM
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I guess I like to make things work if they're not actually dead. If the coil is actually bad (is there a way to check it?), I'll go with the electronic replacement. How does the timing get set up right with that? It just works?

I have the manual from the reference before:

http://www.briggsandstratton.com/pdf...0%5CMS5422.pdf

but I don't see any way to identify the part number for the coil itself. I was assuming (yes, I know what that means... that the armature with plug wire and coil came as one part, is that NOT correct, you just replace the coil on the armature itself? (assuming I didn't go with an electronic replacement).
 
  #14  
Old 03-07-08, 08:56 PM
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I doubt your coil is bad. It's the points that give trouble. The new coil eliminates the need for the points, so you can just clip the wire off and leave them alone. The coil, armature, and wire are all one unit. You just install the new one and go...no timing involved. It uses the signal from the magnet on the flywheel to time the spark. Put a business card (or .010" brass feeler guage) between the armature legs and the magnet on the flywheel and tighten the mounting screws, attatch the kill wire to the terminal on the coil, and put the shroud back on the engine and start it up. That's all there is to it.
 
  #15  
Old 03-11-08, 11:47 AM
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Hmmmm, I thought the holes next to the crankshaft top were threaded for a standard type puller with bolts that thread in. But apparently not.

So... how does the "real" tool to remove the flywheel work, does it clamp on the outside of the flywheel? I have a 3 hook puller I could use, but I didn't want to risk cracking the flywheel itself doing it that way.

Or could I thread the holes with a tap and then pull it?

I don't want to become a small engine mechanic, so don't want to buy a specialized tool for this if possible.

Thanks for suggestions.

Rich
 
  #16  
Old 03-11-08, 11:52 AM
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Hmmm, I just looked up the puller via google and it's only $5, but it just looks like a threaded long nut, not sure how to even use it, is it simple but I'm just missing the idea?
 
  #17  
Old 03-11-08, 11:59 AM
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ah, got it off. Maybe it was the soaking with liquid wrench type stuff I have, but I found a note on another site that just said put a prybar underneath and whack with a hammer. I whacked a couple time at one spot, rotated the flywheel 1/3, 2 more, rotate 1/3 and second whack and it popped right off!

Now, what's the point gap _supposed_ to be? Apparently it's almost always .020.
 
  #18  
Old 03-11-08, 01:05 PM
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Cleaned the points, reassembled everything, and it started on the 3rd pull (a bit of starter fluid probably helped... and kept running, and it's running great again.

Thanks everyone, and this website!
 
  #19  
Old 03-12-08, 12:10 AM
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Great! Glad you got it going.
 
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