Here's a video of my 20+ year old lawn tractor starting up. https://youtu.be/sclnbQk0Z3s She's pretty loud. I can't tell if it's the muffler that's shot or the engine knocking. What do you all think?
Briggs and Stratton 15.5HP engine running loud
- Thread starter clippy
- Start date
I wouldn't worry about it ,,,,,,,its a Briggs . The last Briggs I had was a 1979 16hp in my previous garden tractor . It knocked for the last four years I had it . That old engine had almost 4000hrs on it . Ran great, smoked a little, knocked some too but was still the same when I sold it last year .
North Idaho Wolfman
Moderator
Staff member
Lifetime Member
Equipment
L3450DT-GST, Woods FEL, B7100 HSD, FEL, 60" SB, 743 Bobcat with V2203, and more
I wouldn't take it on any road trips! 
I'll have to post a video of my 1980's Simplicity with a 10HP Briggs, it smokes more than a Southern BBQ!
Can't get parts for the motor and can't get a rebuild kit either, so I have a 16hp Honda that's going to replace it.
I'll have to post a video of my 1980's Simplicity with a 10HP Briggs, it smokes more than a Southern BBQ!
Can't get parts for the motor and can't get a rebuild kit either, so I have a 16hp Honda that's going to replace it.
Change oil to 30w and run it.
Rebuild or replace, same money. Especially if you pay a shop to do it.
My mtd knocks too.
Bought a new one 3 years ago, dont regret it for a second.
Rebuild or replace, same money. Especially if you pay a shop to do it.
My mtd knocks too.
Bought a new one 3 years ago, dont regret it for a second.
Daren Todd
Well-known member
Lifetime Member
Equipment
Massey Ferguson 1825E, Kubota Z121S, Box blade, Rotary Cutter
My old roommate had an ancient briggs and stratton in a self propelled push mower. Never checked or changed the oil in it and smoked like a chimney seized it up one day doing the yard. I pulled the plug and started soaking the top of the piston with some hilco lube. After soaking for about 5 days morning and night, i took a wooden dowl and layed into the cylinder with the dowl and a bfh. Got it to free back up. Dumped the oil out of it. Put in straight lucas oil treatment instead. Filled it up with gas and gave the pull cord a yank. Darn thing fired up first pull after about a minute it quit smoking. Guy still uses the darn thing to do his yard I fixed it for him 15 years ago
seized it up one day doing the yard. I pulled the plug and started soaking the top of the piston with some hilco lube. After soaking for about 5 days morning and night, i took a wooden dowl and layed into the cylinder with the dowl and a bfh. Got it to free back up. Dumped the oil out of it. Put in straight lucas oil treatment instead. Filled it up with gas and gave the pull cord a yank. Darn thing fired up first pull after about a minute it quit smoking. Guy still uses the darn thing to do his yard I fixed it for him 15 years ago 
My dad used to work on lawnmowers and stuff when I was a kid....many many moons ago. The biggest problem with over half the ones he would work on that sounded as if they were knocking had carbon build-up on the pistons. He would always ask if they let it idle a lot and if so that was bad for them. They were meant to run wide open to keep the pistons clean and keep them cool as they were air cooled.
I would pull the spark plug and take a small light and look at the top of the piston and see if its caked with carbon. You can also check the play of the piston at top dead center if it is a loose rod or piston pin. Good luck on it.....
I would pull the spark plug and take a small light and look at the top of the piston and see if its caked with carbon. You can also check the play of the piston at top dead center if it is a loose rod or piston pin. Good luck on it.....
Thanks for the responses everyone. I kind of thought it was more knock than muffler. I don't really have the time (or skills for that matter) to dig into the engine. If it had been a muffler I probably could have (relatively easily) replaced it. I'll probably run the poor thing into the ground. It would be interesting to see how much life it has left.