LV195XA Piston Ring Job

[blues124]

My Toro 20071 mower locked up this summer and the blade wouldn't rotate. I turned the mower on its side and stepped on the blade, which forced it to move. After that it ran OK. I changed the oil and rebuilt the carb not too long after that and now it runs well. While I was doing that I took the valve cover off and saw that the cylinder was badly scarred. I'm not sure how that happened, since I'm good about changing the oil. I did buy it refurbished - perhaps something happened before I got it.

Anyway, now that the season is over, I am thinking about taking the motor apart, smoothing the cylinder walls and replacing the rings. I know I will need new rings, and a gasket set. Should I expect to replace the piston head as well, or is it likely I can smooth that out with my Dremel? I have another old mower motor I took apart for fun and have buffed out scars from the cylinder wall with the Dremel on that one, so I'm fairly confident I can do it on this one as well. Any other advice, or things I should buy to prepare for this? At worst I figure I can always buy a piston head if I get in there and it's in terrible shape.

Or, should I just leave it the heck alone since it's running well now? I'm just trying to extend the life of the mower, but I've never been one to settle for "if it ain't broke don't fix it".
Full details, the motors is a Tecumseh LV195XA, spec 362089E. The mower is a Toro 20071 made in 2007.

Thanks in advance!
-Steve

 

[reynoldston]

I am a thinking what you mean piston head is what I call a cylinder head? Don't know how you can remove the valve cover and see the cylinder walls? If the cylinder walls are scored a Dremel would be the last tool I would use.. A cylinder hone would be a much better tool. Now to do the job right have the cylinder reamed at a machine shop and buy the proper oversize piston and rings. Other then that just run it like it is.

 

[Rivets]

Like reynoldston says, run it until it dies as is. Sticking money into that engine would be a waste.

 

[blues124]

Yes, I meant cylinder head. I understand the Dremel would ruin the concentricity of the cylinder, so it makes sense not to do that. I do have a friend who could machine it for me, but it sounds like it might not be worth it.
I have changed the oil, but cant help wonder if there are chips trapped in the rings causing more damage. I could disassemble it all and just clean it up. Is it worth it, or just "let it ride?"
And, out of curiosity, is this engine a notoriously bad one, or why do you say that engine is not worth it?
Thanks for the help and advice. I do truly appreciate it.

 

[Rivets]

That engine is a good engine, but trying to rebuild it the way you are talking would be more expensive than the engine is worth. I have all the tools to rebuild an engine, plus can get new parts at cost and still wouldn't waste the time.

 

[reynoldston]

I would say just price out the parts and machine work. Then price out a engine if you can find one? Also just maybe you can find a good used block or engine on E-bay. I had a Briggs this early spring had a scored cylinder and all I did was put a new set of stock rings into it after I honed the cylinder wall. The customer has ran it all this pass summer and still running strong. Customer didn't want to spend much money. Your time and money so you have to be the judge of what you want.

 

[blues124]

I enjoy the learning experience of taking apart the engine, so the time doesn't concern me much, and just a set of gaskets and rings wouldn't cost too much either. My machinist friend owns a CNC mill, as well as a manual mill & lathe, so I'm sure he can help me do it well. He probably already has the hone as well. I don't want to sound like I'm hell bent to do this, but I do find it fun and interesting, so I don't mind doing it either.

So, if I lightly hone the cylinder, will the stock rings be enough, or do I need to buy slightly over-sized ones? If over-sized, where can I find those, or how much oversize would be correct?

Many thanks once again.

 

[reynoldston]

Honing a cylinder wall is just to take the glaze out, not going to oversize. If you are going to hone you want to get out any sharp metal that will catch the rings and break them when they pass over them. You will still want to keep your stock sizes, To ream out to oversize has to be done at a machine shop then you need to go to oversize. It all depends how deep they have cut to determine what oversize you will need. Like I said you are the person doing it and know what you want. Sounds like me when I started out in this trade.

 

[jp1961]

If the scoring isn't too deep, a brake cylinder hone for automotive use works well for honing cylinders on small engines. I bought mine from a N.A.P.A. auto parts store.

Jeff