ybsxs.5012vp / 274826 / craftsmam LT2000 lawn tractor/ 2 wisconsin seasons old/ running sae 30 oil

a few months ago I started hearing a lower end noise coming from my rider as soon as the oper. temp was up. Sounds somewhat like piston slap. I finally got to take the motor out and split the case.

I am not familiar with the AVS counterweight system...this looks wierd. I checked the main bearing for play, feels tight, minimal play. I looked at the cylinder wall, no major scuffs/piston still in one piece. The counterweight moves freely back and forth and seems to make the noise I am hearing while engine is running. I don't remember this engine being this loud when it was new. Are they typically a loud engine?

no major shavings in oil and no unusual wear marks in case. Do I put it back together and run it? Or is there something else I should be looking for?


thanks for any replies.

 

there's a possibility the noise is not related to what you suspect. Sometimes the flywheel is just a bit loose and it will make a knock. Some Briggs engines have a knock in the lower crank main if its a bushing rather than a bearing. That is normal if it's a bushing.
I would run it being cautious and make sure it isn't getting any louder. If it seems to be getting louder I would get a second opinion from a briggs shop.

S/T

 

Check the bushings/babbetts in the balancer. Often times the upper one gets worn and knocks. Also, the pto pulley can get loose and knock. I've heard these intek twins knock early on in their life. I haven't opened one up looking for the source yet though. Seems like everyone wants to run it 'till it quits, and I don't guess I blame them.

 

If your gut tells you the noise is internal, buy the correct Briggs manual and tear the engine down and measure all the bearing points. Hopefully you have all the right tools necessary to do this. "Do it once and do it right". Why buy a new engine down the road if it can be diagnosed now.

 

Thanks for the replies so fast.

I do not have all the correct tools for teardown/inspection . Splitting the case looked pretty easy and I wanted to see if there was any 'common' failures with these motors/if there was any major wear in the case already.


Pulley is tight/flywheel is good. What bothers me is the noise gets louder as she warms up. It kinda acts like a bearing issue. Maybe I will do like when I was in highschool and run sae50 to shut 'er up


I think I might just take it to the shop and have someone tear it down. Anyone have book time on this engine for teardown?


My gut feeling on this is after the oil thins out the balancer starts moving around in the case and slapping the side. I will check the upper bushing by hand to see if there is any play that.


thanks again

 

I just realized that your engine has a different balancer system than I described, so my last post won't apply 100% to your engine. I was thinking of a single cylinder engine balancer.

It's not a cheap engine to buy, so fixing it now before it fails would be economical. I wouldn't reccomend the sae50 oil though. I think it would actually fail quicker with that than the 30. I've seen a few engines with 50wt gummed up inside to the point that the engine quit oiling and came apart.

 

Ya..this has a weird counterweight system to it. I will probably just take it to someone and have it gone thru.


don't worry,,the 50wt is something i wouldnt try. thanks again