Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixable?

[greynold99]

Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixable?

Hi everyone,

I hit a stump with my mower, blade is bent on one side and I couldn't pull the starter rope afterwards. It felt like the pulley was binding on something and wouldn't turn, though I was able to pull it a short distance after working with the rope a while.

It has a Briggs & Stratton 500 Series engine/158 cc/5.00 ft. lbs Torque
Model # 10T502-1022-B2

I was hoping someone would know if these engines are repairable or just trash after hitting something. On an older Murray mower I have with a B&S 3.75 Engine, the driveshaft no longer had a shear-pin on the blade/shaft mount spindle. But, I haven't even had a chance to look at the Weedeater mower yet to pull the blade or check the shaft at the flywheel.
I remember on the older lawnmowers, there would be a shear pin with the blade and one mounted with the flywheel that you could replace (That's how long it's been since I had to replace one...)

Thanks for any insight/help you can provide.
greynold99

 

[silver1]

Re: Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixab

Hi everyone,

I hit a stump with my mower, blade is bent on one side and I couldn't pull the starter rope afterwards. It felt like the pulley was binding on something and wouldn't turn, though I was able to pull it a short distance after working with the rope a while.

It has a Briggs & Stratton 500 Series engine/158 cc/5.00 ft. lbs Torque
Model # 10T502-1022-B2

I was hoping someone would know if these engines are repairable or just trash after hitting something. On an older Murray mower I have with a B&S 3.75 Engine, the driveshaft no longer had a shear-pin on the blade/shaft mount spindle. But, I haven't even had a chance to look at the Weedeater mower yet to pull the blade or check the shaft at the flywheel.
I remember on the older lawnmowers, there would be a shear pin with the blade and one mounted with the flywheel that you could replace (That's how long it's been since I had to replace one...)

Thanks for any insight/help you can provide.
greynold99

It can be repaired, but at what cost? Remove the blade. remove the spark plug. See if you can get it to turn freely.
Then see if the crankshaft is bent as you turn it. It just would be better to replace it and recycle.

 

[greynold99]

Re: Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixab

Silver1,
Those were my thoughts as well... And basically it sounds as though B&S hasn't completely gone to the 'Throw away and buy new' philosophy.
Once I get a new blade I'll tear into it this weekend.
If only a shear-pin or two is needed, I'm hoping it's a easy fix.

My backup high-mower is a 25 year old 3.0 hp Murray mower (No priming bulb and no flywheel brake), that I mounted with Angle and Flat strap steel to mount the wheels 8" high.
Wife calls it my 'Frankenmower' because I've patched it with steel door hinges, JB Weld and that Plumbers epoxy over stainless steel screen to cover the holes and cracks in the frame.
I hated pulling that thing out, because the Weedeater mower is basically 3 priming pumps and one pull to start, but was surprised how easy it started after only 4 or 5 pulls and not having been used since last year.
It's also my steep bank mower/on a rope because it's so light compared with lawnmowers today.
Thanks,
greynold99

 

[Fish]

Re: Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixab

Don't buy a new blade until you see if it is fixable. With the plug out, and it won't turn freely, means that the shaft is bent up
in the bearing area of the engine, and will seize/and/or leak oil.
If the bend is below there, it can be repaired by someone with the proper press.

 

[silver1]

Re: Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixab

Silver1,
Those were my thoughts as well... And basically it sounds as though B&S hasn't completely gone to the 'Throw away and buy new' philosophy.
Once I get a new blade I'll tear into it this weekend.
If only a shear-pin or two is needed, I'm hoping it's a easy fix.

My backup high-mower is a 25 year old 3.0 hp Murray mower (No priming bulb and no flywheel brake), that I mounted with Angle and Flat strap steel to mount the wheels 8" high.
Wife calls it my 'Frankenmower' because I've patched it with steel door hinges, JB Weld and that Plumbers epoxy over stainless steel screen to cover the holes and cracks in the frame.
I hated pulling that thing out, because the Weedeater mower is basically 3 priming pumps and one pull to start, but was surprised how easy it started after only 4 or 5 pulls and not having been used since last year.
It's also my steep bank mower/on a rope because it's so light compared with lawnmowers today.
Thanks,
greynold99

The B&S don't have spear pins like a boat prop. It has keys. One is on the flywheel. If that has broken and the flywheel has moved, it will not start.
Good luck with the tear down.

 

[greynold99]

Re: Briggs&Stratton 500 Series/158cc/5.00 ft lbs Torque Hit stump, won't start; Fixab

Fish & Silver1,
I did the tear down this weekend and found that the flywheel key or shear pin had not even been 'sheared' and only had a dent in it from the shaft; but I decided to replace the key anyway. While doing so I checked for any oil leaks around the shaft and if the shaft presented any kind of 'wobble' - but didn't find anything that looked wrong.
Once done, the mower started right up when I got it put back together without a blade.
The big surprise was the next day when I picked up the new blade and the cost was $16.00. Last time I bought a blade, I think it cost about half that.

The only other thing I noticed was that the engine, once started, didn't seem to run at as high an rpm after starting and seemed on the verge of stalling until completely warmed up - which I did by gently toggling the lever mechanism below where the air filter is bolted on. I could gently pull on this lever to get the rpm higher and then, once the engine warmed up - it would run continuously on its own but at a slightly lower rpm than what I remembered.
(I could shut the engine off by toggling this lever in the opposite direction to the far position in that direction. It's kind of like an 'L' or 'V' lever with the spring attached to one of the ends of letter and central pivot point)

There's a small steel coil spring with a long/straight end that fastens onto this lever, that when I pull on it, actuates that lever and I could move it gently to get the engine to run at just a little higher rpm. I'm wondering if that spring got slightly deformed or stretched when I hit the stump and now needs a slight re-adjustment to get back to spec.

Thanks for your help,
greynold99

 

[greynold99]

New blade scrapping inside of mower deck, opposite the grass ejection port...

Well, one more hopefully minor issue...

When I put the new blade on and started the engine - one pull after 3 priming pumps; I immediately heard the blade banging on the inside of the mower deck.
Flipping it over, it looks like the frame got bent just little from the stump hit - the blade-height as I manually turn it appears to be something less than a 1/4" difference higher on that side where it's hitting.
And, I can see a little bit of daylight on the top-front where the engine mounts onto the deck that I don't see on the rear.
The engine is mounted with 2 bolts on the back and one on the front where it got bent.

Do you have any good ways to get the blade level again. I'm thinking of loosening the 2 rear engine bolts and tightening the front bolt to see if it can be brought down a bit. I suppose I could put a couple of steel washers on the two rear bolts to bring them in alignment with the front bolts misalignment.
I mean you could probably slip a piece of paper between the space but not much more.
Thanks,
greynold99