Anyone here know a lot about smalll engines? (lawnmower)

[Linflas]

Here in Virginia we have been living in the monsoon season for the month of May which has caused my lawn to grow like crazy. It was getting so bad that we have had to start mowing while the grass is wet because it is getting so high. I was mowing my yard yesterday and managed to hit a large rock my wife has in one of her flower beds that was completely hidden by the grass. It stopped the mower and bent the blade. It is a Craftsman mower so I ran up to Sears and bought a new blade and put it on but when I started the mower it has a pronounced vibration that was not there before. Is it possible that the shaft itself could be bent? About the only other thing connected to the blade other than the shaft itself is a sleeve fitting that slides over the shaft with a half moon key. I can't imagine that I could have bent the crankshaft but I guess anything is possible.

 

[Eli]

/me raises hand

Yeah. Assuming the blade was already balanced, the crank is bent... that's exactly how it happens.

Just use it how it is. It will probably still last the season. If you tell me the model number on the engine, I might have a crankshaft for it. If it's a Briggs and Stratton, the model number will be found stamped on the flywheel shroud.

I, too, hit a big rock with the mower last week while mowing. I just went on mowing...

Unless it's really, really bad.. the engine could potentially last a while longer. The bearings are going to suffer. Since the lower main bearing sits in oil, eventually the wobble will wear the bearing, and cause the oil seal to fail.. at that point the engine is officially junk. But that could take a long time.. or it could not. Most likely, it will be fine.

Is it an older mower with a 3.5HP Briggs, or a newer one with a 5+HP engine?

 

[Linflas]

Briggs 6.5 IIRC. If I can get the rest of the summer out of it I will be happy since we have been discussing replacing it anyway. It does a horrible job of mulching and the propulsion is almost worthless.

 

[Eli]

Ah, probably won't have a crank for it, then.. But it's possible. Go ahead and throw the model# my way.

Yeah, I'll bet 10 bucks it will last the season.. Unless it's really unusually bad, it won't cause any immediate catastrophic failure. Maybe just make sure the blade is on nice and tight.

When you junk it, I'll pay shipping for the engine.

 

[Linflas]

I will check the model and PM it to you when I get home, thanks. So who makes a self propelled mower that can either bag or mulch? A neighbor of mine has a Honda that seems to do a great job but I know that all their mowers are belt driven until you get to the Masters series. I have now had 2 belt driven mowers and neither one of them has impressed me.

 

[Eli]

Honda makes excellent small (and large..)engines.. But unfortunately, hitting a large rock can kill any crankshaft.

We have an old Craftsman 20" self propelled mower with an old abused anemic 3.5HP Briggs. It's so powerless that I shortened the governor spring... so instead of cruising along at 2900RPM while mowing the lawn, it screams at almost 4000.

Running 20W-50 in it because the rod knock is quite bad with 30 weight.

I'm just waiting for it to throw it's rod at me... so I can put a different engine on it.