Systematic Noise Removal in Original

C5rider · #1 03-23-2013, 05:00 PM

I have been chasing down various sounds and rattles throughout my recently-acquired Original. I've replaced bearings in the S/G, tightened up the steering, etc.

As I move forward, I'm noticing the next loudest noise. Turns out that I think I've got a noisy bearing in the engine. i hear it most when under some load and it is more distinct once it warms up. I would like to address it before I go through and clean/paint everything and before it gets too bad. The engine does have a tag on the side of the engine but someone (P.O.) took a wire wheel to it, so you can really only read the stamped numbers. They are 660220 on the first line and 28542B on the second.

It's definitely a 7hp, but is it a K171 or 181? How do you tell them apart? Here is a picture of the engine. If there's anything else that would help, let me know and I can get a picture or whatever.

Would a standard rebuild kit work for these engines? I see kits on Ebay regularly for early Kohlers. Are the 7-horse versions any different?

thanks!

dvogtvpe · #2 03-24-2013, 09:50 AM

what does it say on the id tag on the side of the fan shroud? if you are unsure if it was ever short blocked take the head off and compare bore and stroke between the two. the only bearing in the engine that seams to cause noise is the rod bearing. that's more of a knock. more noticeable when accelerating or decelerating and while the engine coasts to a stop. the main bearings are ball bearings. I've never seen one fail. I've seen excessive cam or crank end play cause engine noise's since they have helical cut gears. a worn bore will cause piston slap. more noticeable when its cold. as the piston warms up and expands sometimes it goes away. did you take the drive belt off and run it that way?

C5rider · #3 03-24-2013, 02:13 PM

Thanks for the info.

So far as the ID tag, someone wire wheeled it (or something) so there is NO legible writing on it whatsoever. The only thing left is where they stamped those numbers in the tag. Burning up some Google-fu, I think I've found out that the 28542 numbers show that this is a small-bore K161. I'll check a little bit more and see before I tear into anything.

Thanks for the suggestion of pulling the belt. Thinking about it, the rag joint is suspect and the front bearing on the shaft was squealing before I gave it a drink of lube. I've got a new rag joint ordered and while it's all out, I'll go ahead and replace the bearing on the shaft.

Thing is, the engine runs SO GOOD! There's no noise on start-up, which is where I would have thought that a rod would be most noticable.

I'll be checking the driveshaft and rag joint first and let you all know what I find out.

thanks again.

C5rider · #4 03-27-2013, 04:27 PM

I went back and checked the engine. When I rotate the crank by hand, I can hear that there is some play in SOMETHING. I know, not very helpful or descriptive.

I would call it excessive play, but I'm not sure that it is, excessive. There is NO movement of the crankshaft when I try to work it laterally (vertically or horizontally) but when I rotate it by hand, about 1/4-inch of rotation, I can hear a clunk. What it seems like to me, is possibly the camshaft gear has some play in the gear that mates with the crankshaft. Or, possibly the governor gear?

I don't know how much play there shold be, but it sounds like mine might be on the outer edge of allowable specs. All of this is from my un-educated experience so, I could be dead wrong. Maybe it's normal.

I'm considering whether to buy a gasket set and prepare for a rebuild. I've determined that if I'm going to crack the seal on the engine, i might as well do it completely. I've done various V-8s over the years but this would be my first single cylinder engine in quite a while. It would be good to get back inside to refresh my memory, but if I don't have to...

But, I want to re-paint the tractor and if I'm going to do it, now would be better than after the paint dries. I've been known to over-think things and I'm trying to figure out whether that is the case here or not.

Anyone got any insights, encouragement or, just eager to see a fellow Kohler owner jump off the cliff?

Sam Mac · #5 03-27-2013, 05:54 PM

C5 whatever is making noise is not good. Could be a lot of things and you won’t know until you open it up. Whatever it is it won't get better as we all know. If you can do a SB Chevy you can do a lawn mower engine. As my race engine builder used to say “ They all go suck, squeeze, bang, and blow” .

C5rider · #6 03-27-2013, 08:23 PM

Yeah, I'm slowly talking myself into a rebuild. Just kind of cozy-ing up to the idea. I'm pretty sure that it'll happen and I'd rather do it before something decides to change position drastically.

Yup, done small block Chevy, big-block Fords, Desoto Hemis and even dug into some flathead Fords in my day. Last one was my supercharged LT1 pushing 10lbs of boost. Should be nice to work on something that doesn't require a lift!

I think a gasket set is in order. I'm not looking at making it a powerhouse (more than a stock, single-lung Kohler already is) but basically making it reliable for the NEXT 40-50 years like it's already been.

Maybe I'll order in some gaskets and continue the saga in this thread. Anyone interested?

Yosemite Sam · #7 03-27-2013, 09:52 PM

Quote:

Originally Posted by dvogtvpe

if you are unsure if it was ever short blocked take the head off and compare bore and stroke between the two.

Maybe I missed something but I'm not at all sure what "two" we're talking about.

However, I do have to agree... Use the process of elimination Take the belt off so you can find out if the noise is in the engine or not.

If you do have to pull the head, the bores on the K161 & K181 are both 2.938" Where as the strokes are 2.50" and 2.75"

C5rider · #8 03-28-2013, 01:02 AM

Yup, I did narrow it down to the engine. Seems to be louder in the front of the engine.

I agree, I don't want to find out the hard way that something was giving a warning the whole time (and I didn't listen).

Now, as for the bores Yosemite, werent the earlier (28542) K161s a smaller bore? Soon enough, I'll find out, but I remember reading about that.

That's what leads me to believe that there might be some useful info in doing a thread on tear down and freshen-up of this engine. Who knows, maybe it's just my vain attempt at stardom.

dvogtvpe · #9 03-28-2013, 09:39 AM

2 7/8 or 2 15/16 if I remember right

C5rider · #10 03-28-2013, 09:42 AM

I remember that there's a difference. I've seen the question asked about this several times but have not seen anything definitive on it. Looking to find out more as I believe I've got an early one here. Only a couple of bolts keep me from knowing for certain. That, and I need to clean off the workbench!