Know about Briggs and Stratton engines?

[e9999]

I just got a B&S 5hp engine (model 135232, type 0036 01, code 9504122D) with a pressure washer from a neighbor who said it's busted and was throwing it away.
Figured I could have some fun taking it apart and maybe trying to fix it. Sure enough, as far as I can tell after taking most of it apart (fun!), the only thing wrong with it seems to be the busted key between the starter and the crankshaft, which had the effect of locking everything up, strangely enough. Combustion chamber wasn't even bad at all. So it should be an easy fix probably if I can find or make a key. (Interestingly, it seems that is was an aluminum key that indeed sheared. Probably intended as a weak point?)

Anyway, a spring got loose while I was scrubbing it and I want to make sure I put it back correctly so the engine doesn't try to go 50,000 rpm on me.

Picture the rod that comes down from the throttle to the area near where the governor lever is coming off the crankcase. At the end of this rod there is a lever with a spring on it. That's the one that came off. Looking at it, I'm guessing that the spring should be connected to the governor linkage (rod going up to the carb). What I think that does is that when the throttle is all the way on, there is a strong tension on the governor linkage, but not when the throttle is off.

Here are a couple of pics. The first one is showing the spring in tension when the throttle is max. The bigger rod is coming down from the throttle. The thinner one is on the governor. The top of the spring in the pic is where it was unattached and where I decided I should probably put it on the gov lever. Second is with the throttle off and the spring is compressed with the U end protruding over the governor lever. Does that look like I set it up properly?

 

[Michael Hanson]

Looks right to me. I would wonder why the key broke? Mike

 

[e9999]

Looks right to me. I would wonder why the key broke? Mike

may have had a flaw? It looks like it sheared at a diagonal, probably matching the "cone" shape of the crankshaft. The starter cover also lost a couple of crimped nuts, probably from the guy pulling too hard after the thing locked up. It's pretty odd it did lock up, though. Maybe a bit of key got into the clutch. When I picked it up I thought that the piston or rod had exploded, everything was locked tight with no give. I did take the crankcase cover and cylinder head off and the moving assembly seems to be fine, I can rotate it easily.

Are the rewind keys aluminum originally on these things?

Oh oh... I'm seeing in some parts listing on the web that the crankcase cover gasket comes in various thicknesses. I just put some Loctite make-a-gasket cuz I busted the ole gasket. Is this really critical? Crankcase bearing play and what not?

 

[Koffer]

are you talking about the flywheel key?
They are made to shear off if the motor stops too quickly like with a lawn mower hitting a stump , more or less keeps the rotating mass of the flywheel from doing more damage. It will also happen if the nut gets loose on the flywheel to crank .
Any mower shop should have the key in stock for around a buck or so .
I started out on small engines, picked many a lawn mower from the trash when doing my paper route (back when kids did that sort of thing) and brought it back to life
Its sort of fun to tinker with them still as parts are cheap and simple to work on .

 

[e9999]

are you talking about the flywheel key?
They are made to shear off if the motor stops too quickly like with a lawn mower hitting a stump , more or less keeps the rotating mass of the flywheel from doing more damage. It will also happen if the nut gets loose on the flywheel to crank .
Any mower shop should have the key in stock for around a buck or so .
I started out on small engines, picked many a lawn mower from the trash when doing my paper route (back when kids did that sort of thing) and brought it back to life
Its sort of fun to tinker with them still as parts are cheap and simple to work on .

yes, the flywheel key. Are they all made of aluminum? I can't quite see what could have stopped the engine suddenly, though, as it's a pressure washer and the pump seems fine.

I need to look a bit into this crankcase gasket issue.

 

[D'Animal]

The crankshaft endplay is important.

All flywheel keys on the little B&S and Tecumseh engines are aluminum. Read Koffers post above since it is accurate.

 

[e9999]

found some keys at a Tractor Supply store easily enough. Supposedly works on all BS engines (shouldn't they have different sizes for small and big?)


So, I guess I should go with the same thickness as the original gasket then eh?

gotta look for a service manual. Any hidden ones on the web?

 

[e9999]

so, everybody else good on that spring too before I fire it up?