# Briggs Engine on a Craftsman Snow-blower



## Peasaint (Jan 1, 2016)

I've got a question on an older snow-blower I was given by a friend. The machine stopped working for him, would no longer turn over. in fact it appeared to be "jammed", as the crankshaft would only rotate around 60 degrees. 
When I received it, the engine, a "Briggs and Stratton" 21A414-0017 showed to have a severely scored/gouged cylinder, running along the radius of the cylinder. It's deep, at least .080 and along the front of the cylinder wall. Some signs of over-heating on the opposite radius, appearing as light "gloss". This is a "Kool-Bore Aluminum" engine as per the description on the "B&S" website. I've purchased a new engine on line (20M314-0136-F1 / 14.50) to replace the engine that failed. Again it's a aluminum engine cylinder block (Kool-Bore), a step down from the original H.P. from an 11.5 to around 9.5. I don't want the same thing to happen on my 'new' engine'. Has anyone an opinion as to what happened to the original engine? The piston and rings appeared to be fine, as was the crankshaft and cam, and the connector rod.
My friend is a Engineer and knows his stuff, but he can't explain the gouge in the cylinder as a radius. He stated the engine did over-heat, but it was shut off at that time. Here are the engine numbers from what I have, as well as the snow-blower model number.
"Craftsman": 11.5 HP Power Propelled 30" Two Stage
Model Number: 917.881151
Engine: "Briggs and Stratton" 21A414-0017 
From the "B&S" website: 21C214-0553-E1

Replacing with a pending 20M314-0136-F1

Anyone with any info, or ideas, ... please let me know. I'd hate to have a repeat of the same problem this and/or next season. Thanks in advance.


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## Bolens 1000 (Dec 23, 2015)

Only things that could have happened,

-Low/No oil

-Something came loose in the upper cylinder

-Engine was run too lean and seized up (Overheated)


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## Peasaint (Jan 1, 2016)

*Briggs Engine on Craftsman*

Hello Bolens 1000, thanks for your reply.

The engine was taken care of, ... I've no doubt. The fellow I got it from is very watchful, but something happened. His driveway is a long one, very steep and winding. It indeed perhaps over-heated on the accent up the driveway (not sure what he was trying to move as far as a snow-fall amount. That certainly would put a strain on the machine, ... but the gouge is severe, ... however the rings are okay as is the piston itself. I suspect something "moved", but the cylinder block on this machine is an all in one unit, as there are no parts that could be moved independently themselves within the 'engine block'. Thankfully, my area is all flat, though large, ... I've no sharp inclines to meet.

Thanks again for your reply, I really appreciate it. Have a safe night!


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## skutflut (Oct 16, 2015)

Peasaint said:


> Hello Bolens 1000, thanks for your reply.
> 
> The engine was taken care of, ... I've no doubt. The fellow I got it from is very watchful, but something happened. His driveway is a long one, very steep and winding. It indeed perhaps over-heated on the accent up the driveway (not sure what he was trying to move as far as a snow-fall amount. That certainly would put a strain on the machine, ... but the gouge is severe, ... however the rings are okay as is the piston itself. I suspect something "moved", but the cylinder block on this machine is an all in one unit, as there are no parts that could be moved independently themselves within the 'engine block'. Thankfully, my area is all flat, though large, ... I've no sharp inclines to meet.
> 
> Thanks again for your reply, I really appreciate it. Have a safe night!


Was this gouge above or below the piston travel area?
When you opened the engine, were there any bits and pieces of shrapnel laying in the bottom of the crank case? Were you able to rotate the engine with the sump off and see what was stopping it from going more than 60 degrees? 

Were both the wrist pin clips still installed on the piston, governor gear and associated parts all present and accounted for, compression release bits on the cam shaft, valve lifters still in one piece and present? If you removed the head, did you find a bent valve not closing and perhaps hitting the top of the piston? I remember one poster who mentioned that a screw from the throttle butterfly valve came out and found its way into the cylinder through the intake valve but it mainly damaged the top of the piston.


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## Peasaint (Jan 1, 2016)

No "shrapnel' of any kind was present. The piston and it's two rings were freed from the cylinder wall, 'gouged' occurred. That was the spot of the "freeze" on the crankcase (which was being dealt with by hand). It's a single stroke engine (one cylinder), and the two rings were fine as well as the piston itself, and the connector rod is in fine shape, as well as the rest of the internal 'metal' movable structures. About half way into the cylinder wall however, ... there was this gouge. It's deep as I stated, running from a 10 to 2 o'clock position within the cylinder wall. One would think it would be in the action of the piston, ... up and down. This isn't the case in this engine. The person I got it from states that it ran well over the winter of 2014, and into early 2015. he states "it ran fine in January (2015) but I left it out in early February during 1 to 1.5 weeks of very heavy rains, and sub freezing temps at night. When I went to start it in late February, ... it wouldn't crank over, and was getting jammed on something". He went on to replace belts, and other drive parts, but never got into the engine block itself, ... and hence, the parts he purchased never worked out. He offered it to me as an "if you can get it going, you can have it" sort of thing. His thought that rain and the freezing temps did a number on the engine, but that makes no sense to me, especially after the cylinder damage that was found on opening the engine itself. Drive shaft is fine (cam shaft?), piston looks in good shape, no obvious wear within the radius, ... as are the rings and the connector rods. Everything fits tight, ... just can't figure it out. Way too much cylinder damage from a simple over-heating issue. But the cylinder-block is a solid piece ($205 -220 to replace), when everything is secured, ... there is really nothing to go 'nutty' independent of the block. It's got 4 to 5 of us here that have seen it stumped. I simply don't want a repeat on the new engine I just purchased. Why make a cylinder out of aluminum to begin with? The block okay, ... but the cylinder itself should certainly have a steel or iron insert upon it's wall. Just my thoughts and opinion. But as I stated, ... I'm 61 years old, new here, and have never owned a snow-blower before this one. Thanks for any support or replies and thoughts, opinions and such.


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## Peasaint (Jan 1, 2016)

Skutflut, ... thanks for your time and contact. You bring up some really good points and questions. My good neighbor did the 'dissection' of this engine (30 year Air Force Reserve Mechanic), and I'm assuming all parts were there and accounted for. However, ... there is always that "maybe". From my perspective, one who only knows that if a engine won't start, ... it's "broken" somehow. My feeling is that there was a foreign body (also reffered to as "FOD" = "foreign object destruction" for those of us in the industry) that infiltrated the cylinder, perhaps a small stone, a loose screw? But how would it get that deep inside the engine? Thanks for your reply. As soon as the drive wheel is taken off, ... I'll be able to get some photos and will post them. The new engine should arrive on Thursday. I'll drain the small amount of 'testing' oil, refill with fresh as per the specs. I'll also follow some advice hat has been posted on adding a "fuel stabilizer" with a fresh fill of gas. From there I'll just keep my fingers crossed. Thanks so much for your time. I hope I can give you a better answer than the one I just posted in a month or so. Take care, stay warm, and thanks again.


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## Grunt (Nov 11, 2013)

If the throttle and choke plate screws are accounted for and currently reside where they belong, I would venture a guess of a carbon chunk dislodging and causing the unusual gouge, disintegrating and ejected through the exhaust valve. Although carbon causing cylinder scoring is more common in two cycle motors, it is a possibility in your engine. A friend of mine had a 10 hp Briggs which broke a piece off the piston skirt and gouged the cylinder on the lower two thirds of the bore. I will be interested in the actual cause, if found.


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## skutflut (Oct 16, 2015)

Peasaint said:


> No "shrapnel' of any kind was present. The piston and it's two rings were freed from the cylinder wall, 'gouged' occurred. That was the spot of the "freeze" on the crankcase (which was being dealt with by hand). It's a single stroke engine (one cylinder), and the two rings were fine as well as the piston itself, and the connector rod is in fine shape, as well as the rest of the internal 'metal' movable structures. About half way into the cylinder wall however, ... there was this gouge. It's deep as I stated, running from a 10 to 2 o'clock position within the cylinder wall. One would think it would be in the action of the piston, ... up and down. This isn't the case in this engine. The person I got it from states that it ran well over the winter of 2014, and into early 2015. he states "it ran fine in January (2015) but I left it out in early February during 1 to 1.5 weeks of very heavy rains, and sub freezing temps at night. When I went to start it in late February, ... it wouldn't crank over, and was getting jammed on something". He went on to replace belts, and other drive parts, but never got into the engine block itself, ... and hence, the parts he purchased never worked out. He offered it to me as an "if you can get it going, you can have it" sort of thing. His thought that rain and the freezing temps did a number on the engine, but that makes no sense to me, especially after the cylinder damage that was found on opening the engine itself. Drive shaft is fine (cam shaft?), piston looks in good shape, no obvious wear within the radius, ... as are the rings and the connector rods. Everything fits tight, ... just can't figure it out. Way too much cylinder damage from a simple over-heating issue. But the cylinder-block is a solid piece ($205 -220 to replace), when everything is secured, ... there is really nothing to go 'nutty' independent of the block. It's got 4 to 5 of us here that have seen it stumped. I simply don't want a repeat on the new engine I just purchased. Why make a cylinder out of aluminum to begin with? The block okay, ... but the cylinder itself should certainly have a steel or iron insert upon it's wall. Just my thoughts and opinion. But as I stated, ... I'm 61 years old, new here, and have never owned a snow-blower before this one. Thanks for any support or replies and thoughts, opinions and such.


I'm wondering if water got in the cylinder, and caused a line of rust from the piston ring to deposit on the cylinder wall, and maybe when the piston was broken loose from that rust, your gouge was created. Is the gouge the width of a piston ring? Were the rings showing rust, and did you notice any water in the oil when it was drained? 

Briggs does have a line of engines with cast iron liners for commercial applications. Aluminum is for pop cans and not cylinders, but everybody is making them because it makes them light, and cheaper and easy to machine and cheaper. Did I mention cheaper? 

Mine is similar to yours a 305CC B&S with aluminum bore, but it lives in a nice dry garage all year round. Only time it gets wet is when it snows.


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## Peasaint (Jan 1, 2016)

Hello Grunt, thanks for your thoughts. The machine ran fine (supposedly) on it's last starting, and duty. It WAS shut off, then kept outside during last February's rains and temperature extremes for perhaps 2 to 3 weeks. When attempting to use the machine again, it failed to turn over, and the shaft could only be rotated to a certain degree. There was some small amount of carbon found, but the piston itself was in decent shape, as were the rings. Water was found in the oil that was drained, and though hard to determine the exact amount, it's estimated to be almost an 1:1 ratio, quite a bit to have in the oil. You mentioned carbon, ... I'm wondering if "ice" could have been the culprit (forming between the piston and the cylinder wall). Either way, ... it shouldn't have been left outside in the rain, and then the oncoming freeze of the season. Thanks again for your thoughts. As soon as I can get to take photos, I'll post them. Not sure if we'll ever determine the problem.


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## Peasaint (Jan 1, 2016)

Skutflut, if you'll read my reply to "Grunt", ... you'll see that water was indeed found in the oil, and though some carbon was found inside the engine, not enough to be considered as a factor to cause the scoring gouge (perhaps 1/3 into the cylinder) that was noted. But as I stated to Grunt, water was indeed found in the oil. Although the piston head and rings appeared to be as clean as expected, .. I've starting to think perhaps it was a 'vapor lock' of sorts, in the cylinder, forming a large area of ice, gouging the cylinder upon the next attempted use. Then the ice simply melted, leaving no trace as to what caused the problem. Do you think it possible? Kind of like the old lady that beats her husband to death with a frozen leg of lamb, then when the inspector comes to ask questions, he's invited to dine with the widow, consuming the evidence. (an Alfred Hitchcock episode from long ago). Thanks for your reply, as we move along, I'll post.


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