125 engine
 

I was mowing my lawn to day and notice some smoke coming from left side of the engine then started losing power, make more smoke coming out of the breather under the carb and making kinda a knocking sound so I shut the engine down let it set a few minutes and started it back up to move it up close to the house from the end of the road . When I got close to the house it did the same thing what could be the problem ???

Scored a piston. It's toast.

If she runs, dump in more oil and gas and keep goin till it's completely shot.

The motors not toast you can salvage everything but the block or if your hand and wanna rebuild it go ahead or if a friend needs a 12hp give it to them they may wqnt to rebuild it, or send it to me instead of scrap lol

That is absolutely the worst advice I have ever heard. :bash2::bash2:
Don't do that, stop using it and salvage what parts you can. The parts for these motors don't grow on trees anymore. They are starting to get expensive.

When I said it was toast, I didn't mean you can't fix it.... I mean, it's done, wore out, burned up... however you want to say it. And no, the block shouldn't be junk. They can be bored.

Seems I'm sitting here waiting for a flippin train wreck or something:bash2::bash2:

From what you have said, it kinda sounds like your engine needs to be rebuilt. However, it is possible that something else is causing the problem, if you can you give us a little history on the engine (have you been using it all along, is it new to you, has it sat for a long time, when the oil was changed last). Perhaps someone here will be able to give you some constructive advice.

I have been using it all summer no problems .It had maybe 18 hours on the oil change hadn't burned a drop of oil , down half on the stick now I presume it was loss due to vapor, not smoke on the left side of the engine it was puffing a fair amount and then it lost power and made a racket and really puffed out of the breather . I shut it down waited a few minutes and started up again and drove it up from down at the end of the drive way ran up the rpms and started acting up again . This has been running real well I don't know what the problem is and I don't wanna be a darlelict and blow it up and cost more money than I need to

If your getting puffing or large amounts of smoke out the breather, then you are getting blow by around the piston. Maybe it got a little hot? ...... Maybe it just finally wore out. Either way, go ahead and take the motor out, pull the head, pull the pan. You will find some kind of cylinder damage. Scored piston, groove in the block..... It's not necessarily your fault. Seen lots of good running motors fail. Everything has its limit..... sounds like yours is there.

I was responding to what Sam asked for