kohler K301 piston

Z

zack

Well-known member
I need a standard size piston for a k301 I want to use a kohler piston and not aftermarket because I do not like the quality I have seen lately.
I have rebuilt 5 kohlers using aftermarket parts and when ordering a piston you don't have any choices, one 12hp piston will fit all the k series 12hp motors.
now I am trying to find a kohler piston and there a two options
47 874 06-s
47 874 16-s
By going by the spec # and serial # i need piston 47 874 16-s
spec # 47504
serial # 2210108412
The problem I am having is that I have a feeling that the sheet metal on this motor is not the orginal that came on the block. I think the block has been changed in the past, but I am not sure because I bought just the bare block and was given these numbers off the sheet metal.
Does anyone know the difference in these two pistons?
Will both of these pistons work?
I just don't want to order the wrong one and screw up the motor.
 
zack":2gha6y93 said:
The problem I am having is that I have a feeling that the sheet metal on this motor is not the orginal that came on the block.
Click to expand...
Initially, pay no attention to the sheet metal, the nomenclature decal and the previous owner information provided with the block. Measure the cylinder bore. That way you will know for sure what you have. Sheet metal gets changed. Provided information is sometimes wrong.
 
I agree with Eugene, I NEVER pay attention to what the tags say on anything that old, lord only knows how many times parts with tags have been changed over the last 40 years.

That's why I always roll my eyes when someone wants to know what year their tractor is based on what is on the transaxle tag. I try to tell them that I can tell you what year the transaxle is, but I don't know what year the tractor is, and does it really make any difference?

Sermon finished, go in peace.
 
My block is at the machine right know and I stopped in today to see what size piston I needed. He said it would be good to go by just honing it and using a std piston. After my last experience with the aftermarket piston he advised me to use a kohler brand piston. But they said they can only get aftermarket kohler parts or I would have just had them deal with it.

I looked at the chart but maybe I just don't see the whole picture :? , its still not clear to me which piston I should use.

Thanks for the info so far
 
I have no idea what style piston or rod came out of this motor because I only bought the block. I am putting in a new rod but that is aftermarket because the crank had to be ground .020 under and kohler doesn't make a .020 under rod.
 
Who did you get the .020 undersized rod from?

What issues have you had with an engine rebuilt with "after market" suppliers? I've had pretty good luck so far with the K301s and K321 I've rebuilt using an ebay seller that has mostly Stens parts (rod, piston etc..). I'm about to order another rebuild kit for a 125 that will be more of a toy than a worker.
 
I got the rod from a place on ebay.
The problem I had was the last two pistons I had gotten were not the size they were suposed to be they were both a little small. on one of them the ring gaps were way too big.
 
I get my Kohler pistons, actually all my Kohler parts, from the local autoparts store. Not sure who makes the piston. Never had a problem.
 
The machine shop I use gets parts for the kohlers from prime line. the first piston I got was from prime line, I am not sure where they found the second piston but it was in the same packing and it looked the same as the first one. I don't actually know what company makes these aftermarket pistons for primeline and others, but it seems that the quality has gone down hill.

I am thinking I will be able to use the kohler old style piston with my aftermarket rod, but I was hopeing someone had run into this problem in the past.
 
Anything qther than the Kholer rod & piston will have the correct dimension to work. The weight might be different and in a racing engine where they balance an engine it won't be enough to affect the performance of a 3600 RPM single cylinder rebuild and if you are making a racing engine it would have to be balanced after machining. I think even the Stens rod & Piston will out last any good rings you install in it. You can get a defective new part from any manufacture and cause premature failure og the engine.
 
wdeturck I have heard of stens but have never used there parts. The machine shop I use doesn't carry stens but I am sure I could find someone that does. Does anyone on the forum use sten pistons and how is the quality?
 
Hi Zack: I have used Stens parts but that was just an example that I know about. I think you are worrying to much about using non Kohler parts. I don't know how you can judge quality(critical dimensions) by looking at it. I don't think your machine shop would use any parts that aren't up to their standards. I do know that there are a lot of Stens parts being used and don't hear of failures that would cause them not to be used. I think if your machine shop can get a part and used them before it should be OK. A rebuild will never be as good as a Kholer short block.
 
I ordered my Stens rebuild kits off of ebay from this guy:


http://cgi.ebay.com/ws/eBayISAPI.dll?Vi ... MEWAX%3AIT


That specific kit I will probably order today or tomarrow. If you don't have an EBay account just call him and place your order that way. I have ordered from him twice and had good results (for my 1450 and my 125). I did have one issue with a seal on crank shaft for the 1450 kit, it just didn't look right so another was supplied by the guy assembling it for me. He didn't want a freshly rebuilt engine leaking oil. The 1450 has over a year of hard use (tiller, mower and pushing snow) with no issues. The 125 has only seen some snow blowing work so far but it's running great.

My question is, does Stens actually supply Kohler with parts for these older engines?
 
I think i will give stens a try and see what happens.
wdeturck, The two I had a problem with were from primeline, I needed a .030 over piston so the bore would clean up. But the machine shop said the first piston was barely over .020 and the second was just barely larger than the first. so I am now using another block I had which has a good std bore.
I am sure I am worrying to much about the aftermarket pistons, but just want to get this thing back together without any more problems. Its been tore apart for almost two months now
 
You can get bad pistons even in the top brands;
I purchased a new set of forged pistons from TRW and i had one crack along the forge pattern. It was from it not being hot enough during the forging process. I called TRW and complained about it and they only replaced one piston when i said what about the other 7? I have made ash trays out of all the TRW pistons, even the new one they sent me.

Also there is a clearance difference between forged pistons and cast pistons. Forged pistons require more clearance than cast pistons. So we need to know if our pistons are cast or forged when we go to after market stuff. I trust no one now after my problems with TRW. This is why i do all my own boring now too. I'm in control of the quality of my work.

I just purchased some extra overr bore pistons and i hope to get more soon so i can stock everything to rebuild inhouse all my cadets that need it. I have all the gaskets too.
 
dhermesc":36so4q6x said:
My question is, does Stens actually supply Kohler with parts for these older engines?
Click to expand...
I looked up a couple of older Kohler parts in the Stens on line catalog. They did have some parts - not fully researched.

Primeline and NAPA use the same parts numbers and supplier for their small engine parts. Since Stens is a parts supplier - could very well be that the parts came from the same manufacturer. Just changed the packaging.

Same part, different packaging, different retail price.
 
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