Oversize rings or not

[GBertolet]

I am working on a B&S 12H802 1767-E1 engine. It's from a Toro Personal Pace mower. It's using oil, along with low compression. The engine is torn down. The cylinder measures 1.682, and the piston is 1.672, both the old compression rings gap at .050. Being the cylinder is towards the upper end of tolerance, would it be advantageous to get .010 rings for this engine?

More bad news, I had to destroy the drive pulley, getting it off the crank. The setscrew was sandblasted, so there was nothing to grab with the hex wrench. It was very hard drilling, to get a bite for the easyout. Soaking in liquid wrench, and some acetylene torch, finally got it out. Even with the setscrew out, that pulley would not budge. It was rusted solidly in place. No room to get a gear puller behind it. I had the idea of sliding a piece of 1" pipe over the crank, then welding it fast to the pulley, then welding a 5/8" nut, to the other end of the pipe, and using a piece of 5/8" threaded rod, double nutted on the end to make my own puller. Still no good, even when heated with the torch. I finally gave up, slitting the pulley, down to the crank, lengthwise, with a dremel cutoff wheel, both top and bottom, cutting pieces of the belt flange off also, to get the puller behind it. More liquid wrench and torch, and it finally began to move. Eventually it came off. Add the cost of a new pulley to this job. They are not cheap for this mower.

 

[Steve]

I am working on a B&S 12H802 1767-E1 engine. It's from a Toro Personal Pace mower. It's using oil, along with low compression. The engine is torn down. The cylinder measures 1.682, and the piston is 1.672, both the old compression rings gap at .050. Being the cylinder is towards the upper end of tolerance, would it be advantageous to get .010 rings for this engine?

More bad news, I had to destroy the drive pulley, getting it off the crank. The setscrew was sandblasted, so there was nothing to grab with the hex wrench. It was very hard drilling, to get a bite for the easyout. Soaking in liquid wrench, and some acetylene torch, finally got it out. Even with the setscrew out, that pulley would not budge. It was rusted solidly in place. No room to get a gear puller behind it. I had the idea of sliding a piece of 1" pipe over the crank, then welding it fast to the pulley, then welding a 5/8" nut, to the other end of the pipe, and using a piece of 5/8" threaded rod, double nutted on the end to make my own puller. Still no good, even when heated with the torch. I finally gave up, slitting the pulley, down to the crank, lengthwise, with a dremel cutoff wheel, both top and bottom, cutting pieces of the belt flange off also, to get the puller behind it. More liquid wrench and torch, and it finally began to move. Eventually it came off. Add the cost of a new pulley to this job. They are not cheap for this mower.

As far as oversize rings in a not oversize bore, no, there is no advantage. If the bore is out of round then there is no advantage of new rings either. Low compression in a briggs is usually poor sealing of the valves or too tight of valve lash.

 

[Al Smith]

Measure the cylinder for ovality and taper .If it's off by much it will take a month of Sundays before the rings seat .It likely will in time but also at least lap the valves .You might be able to save it .

 

[Dub11]

Is this for a 20332 model?

I'd just throw one of these at it.
http://www.smallenginewarehouse.com/104M02-0012.html

Or move up to.

http://www.smallenginewarehouse.com/FJ180V-AM29M.html

And pulley.
https://www.ebay.com/i/132282171803...=1&pg=2386202&algv=DefaultOrganic&brand=Stens

 

[GBertolet]

Thanks, the valves were caked with oily carbon, which I cleaned up. My lapping suction cup tool is shot, so I will need a new one. The cylinder is within the larger side of allowable diameter specs, plus it is concentric. I have about .035 end play on the crank, which is a little too much. I found a 7/8" B&S crank thrust washer in ebay for $3, and ordered it. I don't know the thickness of these. If it is too thick, I will have to thin it down. According to the manual, my 12000 series engine require any washers to be on top of the crank, not bottom.

Anyhow, new std size rings, and gasket set is on the way. It was quite a chore to get the correct rings ordered. There are so many different numbers listed for this engine. I settled on #499425. The engine is a 6 hp, 12H802-1767-E1, code 99082456, on a Toro Personal Pace mower #20042. I ultimately used the Toro mower specs, to track down the B&S engine rings, using mower number and engine date code.

 

[Al Smith]

I might mention Small Engine Warehouse .It's about 60- 80 miles from me and the least expensive engines east of the Mississippi . If he's still alive a good old boy who hauled from Wartburg Tenn.owned it ,Roy Pagent .He know some of my wifes ' people .At any rate you've never seen so many engines ,pressure washers, pumps and anything with a small engine in your life .It was so many he had them stored on pallets under tarps because the buildings were full .

 

[legdelimber]

Don't forget to check if the blade retainer~ pulley is metric.
Looks like the replacement engines have 25mm crankshafts.
last time I was looking for a mower engine, I ran into the affordable ones would need new pulleys and blade retainers.
Back then, getting the metric tidbits $$ were the deal killers.

I found a closeout/new old stock mower at Walmart for less than buying all of the bits and swapping for the metric engine.
Self propelled model, so the pulley (and blade adapter) was already on it.
My Snapper deck never knew the difference between the Tecumseh and the Briggs.

Too bad the rear drive is in the way of mounting the engine with the cylinder to the rear.
My yard has a lot of twisting and slopes to navigate and it would make for an easier to maneuver mower.
I always mounted the cylinder rearward on any push mower.
But now my knees mandate a self propelled unit and the yard mandates a rear wheel drive, so a side mount cylinder is the best I can do.

 

[Al Smith]

Now another thing about good old Roy is he has connections .I got a dandy deal on a pressure washer because it was the last year they were allowed to use flat head engines .After that they had to be over head .He bought 500 of them and was selling them for a couple hundred under Lowes .Last I heard his son runs the business now .

 

[Dub11]

Don't forget to check if the blade retainer~ pulley is metric.
Looks like the replacement engines have 25mm crankshafts.
last time I was looking for a mower engine, I ran into the affordable ones would need new pulleys and blade retainers.
Back then, getting the metric tidbits $$ were the deal killers.

I found a closeout/new old stock mower at Walmart for less than buying all of the bits and swapping for the metric engine.
Self propelled model, so the pulley (and blade adapter) was already on it.
My Snapper deck never knew the difference between the Tecumseh and the Briggs.

Too bad the rear drive is in the way of mounting the engine with the cylinder to the rear.
My yard has a lot of twisting and slopes to navigate and it would make for an easier to maneuver mower.
I always mounted the cylinder rearward on any push mower.
But now my knees mandate a self propelled unit and the yard mandates a rear wheel drive, so a side mount cylinder is the best I can do.

So you're saying the spark plug should be facing you?

Now another thing about good old Roy is he has connections .I got a dandy deal on a pressure washer because it was the last year they were allowed to use flat head engines .After that they had to be over head .He bought 500 of them and was selling them for a couple hundred under Lowes .Last I heard his son runs the business now .

I have plans to buy a Kawasaki motor from the this winter or spring for a LB deck I have ready. They really have some of the best prices I've ever seen?

 

[Al Smith]

Kawasaki makes a good engine .Can't deny that .

 

[legdelimber]

Dub11, Yeah, I like the plug~cylinder to the rear when practical, for the weight distribution.
Now if you run a rear bagger with heavy damp/juicy grass, it may make the mower a little wheelie prone.
A front wheel drive will loose some traction too.

Sorry I didn't see your question until just now.
The log-off timer boots me out and I miss seeing new comments then.

 

[Dub11]

Dub11, Yeah, I like the plug~cylinder to the rear when practical, for the weight distribution.
Now if you run a rear bagger with heavy damp/juicy grass, it may make the mower a little wheelie prone.
A front wheel drive will loose some traction too.

Sorry I didn't see your question until just now.
The log-off timer boots me out and I miss seeing new comments then.

I'll give this a try on the next LB I come across.

 

[GBertolet]

The rings came today, and I am a little baffled. The top ring is chrome, and has a .010 gap, which is good. The middle ring is of standard material, and has a .040 gap. Should the middle ring have this much gap? Anyhow, the reassembly was uneventful, and it seems to run fine. Compression is much higher. Easily noticeable when starting. I have about $100 tied up in this rebuild. The biggest expense was, the new Toro rear drive wheels for $50.

 

[Al Smith]

If it runs okay I'd just call it a day .On engines that use chrome rings normally its just the top ring .