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MaineDad

K301 Opened Up

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So,

My K301 on my 77 C-120 runs great. It has plenty of power and idles down real smooth. But, it has been burning a few ounces of oil with each use. Yes I check the oil every time before it gets used :hide:

So I decided to pull the head off since I have never see the inside of this engine before so I could see what was happening inside. Look what I found!

K301Before.jpg

I cannot believe this was running as good as it was - what a mess! The intake valve had a ton of carbon build up which was preventing it from completely closing. The piston had zero movement and the cylinder wall was in great shape too. I scraped and scraped, then wired wheeled it completely clean. I then lapped the valves and polished the head and here's what it looks like now!

K301After.jpg

I installed a new head gasket, torqued it down as specified by Kohler, then installed a new spark plug. Started right up! Had to re-adjust the high and low speed idles, it it still purrs! It's amazing how these old K series Kohlers run. I am so glad that I checked into this. I'll keep an eye on oil usage and peak in the spark plug hole every once in a while too. Have you checked your engine lately?

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isnt it great to find a small problem when sometimes a guy is expecting the worse :hide:

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WOW! What a difference! How much to have you over for a weekend and tear into my tractors?? :WRS::hide:

really nice work Micah!

Gerry

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That looks amazing Micah. Nice work! Gotta love those Kohler singles :hide:

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WOW! What a difference! How much to have you over for a weekend and tear into my tractors?? :WRS::hide:

really nice work Micah!

Gerry

Bring one here and we'll clean it up and serve some famous banana bread :)

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That looks amazing Micah. Nice work! Gotta love those Kohler singles :hide:

Thanks. There's piece of mind knowing. You know?

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WOW! What a difference! How much to have you over for a weekend and tear into my tractors?? :hide:

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Nice work, its amazing how the simplest things can return BIG results! :hide:

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Micah, you should have made this a tutorial thread with pics of the process and tools you used. (wire brush) Excellent work, looks new. :hide:

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I hate to be the one to rain on your parade... :hide:

That clean area on the upper left area of the piston is a symptom of blow by past the rings. Did you do anything about that when you had it apart?

Does it still use oil?

best,

hank

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Hank,

I just took the head off and cleaned it all up. There was zero movement in the piston side to side and the cylinder wall was clean and had no scoring at all. Before I cleaned it up, I observed the piston and valves and only noticed that the intake valve had a ton of carbon buildup which prevented it from seating completely. I assumed that was the cause of the minor oil consumption.

I have not used the tractor since the carbon cleaning except to start it and reset the how and low speed idle settings. I will monitor the oil use closely after each use. Hopefully it's not the rings...

Thanks for the insight though. I appreciate all the help I can get :hide:

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Nice work there Micah! :hide: . I/we call the Head Cleaning a 'De-Coke' in the UK. It's an essential maintanence procedure that is often overlooked (or avoided). Should be carried out every 500 hours on these. It also allows the chance to check condition before things get worse.

I have to go with Hank's concerns with the clean patch on the piston. It may only be that the Ring gaps have lined up in close proximity to eachother and lets the Oil through them easier than each Ring gap being equi-spaced around the bore.

If it continues with the same Oil consumption rate as before (you didn't say how long it has been burning oil at the rate of a few ounces), it may be worth checking it out sooner rather than later.

Here's a link to my reply in Yokomist's Post showing the state of my (72) K301 before and after. Note the even cover of Carbon deposits on the Piston indicating good Ring fit and no clean 'Oil Blow-By' patch. This had been soaked with Redex squirted in through the Plug Hole a month before removing the Head. It partially disolves and loosens it so much that it only needs a wooden spatula to remove it.

The Carbon build up around the Exhaust Valve seat was mountainous. Another reason why I always take the Lid off an Engine before trying to run it, if I don't know the history of it.

http://www.wheelhorseforum.com/index.php?...topic=21753&hl=

When you do check it out, it would be a great help and interest to me/us, to post your findings and Pictures.

Regards

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Update:

I drained the oil then removed the engine and got it on the bench. I separated the block from the oil pan then removed the rod cap and piston. There was a slight burning oily mark on the side of the piston nearest the valves. The top ring was extremely loose compared to the other two rings. The rod looked fine.

I measured the cylinder bore with my digital calipers and it was exactly 3.375 inches which is a standard bore for the K301. I am going to purchase a bore gauge kit today from Napa so I can get a complete measurement of the entire bore not just the top. I'll take some pictures of the process.

My hope is that I do NOT have to bore this out to .010 and can just deglaze(hone) the cylinder bore and install new rings. Question - can I deglaze it with the crank and everything else still there?

I may also opt for a new Mahle Piston and matching connect rod. Thoughts on that?

Thanks in advance...

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As cheap as the Sterns kits are, Id go that route and put a rod piston and rings in it. I have see old rods break with new rings and psiton, just old age and being brittle

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i was told that it isnt a good idea to leave any thing in the block,the hones are a grit stone and the block needs to be cleaned after,and any grit in the bearings or on the crank arnt good,but i know some guys do it and try to cover up the lower goodies,and clean it out real good,id take it apart and do new gaskets as well

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Thanks Rick and Don. Update:

Purchased this Cylinder Bore Gauge Kit at Napa for $30. It has many different size micrometers for varying cylinder bore sizes;

CylinderBoreGaugeKit.jpg

I used this one that could measure up to 3 1/2 inches since a K301 standard bore size is 3.375 inches;

Micrometer.jpg

These work pretty slick with the ends being able to move in or out (self centering) so when you find the right place, you just turn the top nut and it locks the sides in their place for a measurement with my digital calipers;

DigitalCalipers.jpg

So with the right tools, I could proceed to measure the entire cylinder bore. I took 6 total readings; bottom, middle, and top parallel to the crank and bottom, middle, and top opposite of the crank. As you can see, my cylinder bore is still within the "Standard" bore size;

BoreMeasurements.jpg

So now that I know the cylinder does not need to be bored oversize to .010, i can proceed with just new rings, or update to the newer style Mahle piston that needs a new matching connecting rod. The crank looks smooth and fine too;

301Crank.jpg

My big problem is trying to deglaze the cylinder walls with the crank and other parts still in the block. I know a lot of people who have done an in-frame hone/deglazing with no problems at all. I just have to do an extra good job at cleaning when I am done.

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Deglaze away, remove engine then wash with soap and water when done, apply a light coat of oil after it dries to prevent rusting

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Update:

A new Mahle standard piston with matching connecting rod has been ordered along with the new gaskets to put this back together. I do have a question though. Should i remove the balance gears while this is open? It looks like I can just drive out the shaft correct?

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Balance gears are out! Snap ring tool to the rescue. Removed the shims too :woohoo:

One less thing to worry about...

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:ROTF: Whats a Mahle piston? Whats the difference between it and a regular piston? :D Info please!! :woohoo:

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:D Forget to ask this in the above post :ROTF: What do you use to polish the head and is there any info on here that tells you how to lapp in the valves? :woohoo:

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Jerry,

The Mahle Piston or Piston style "D" is the 3rd generation Kohler piston used in the newer Magnum engines. They're manufactured in Germany and made of tougher material than the older Kohler pistons. They hold up to heat better and wear longer, too. And they weigh the same as a Kohler piston assembly. Mahle pistons have the same compression height as the K-series pistons. Mahle pistons just last longer under severe conditions, that's the only difference. You also have to get a stronger matching connecting rod if you go this route. Porsche engines use the Mahle brand too :woohoo:

I used a wire wheel brush on my electric drill and some emery cloth to do the carbon cleaning. Regarding lapping the valves it's pretty easy. Do a 'Valve Lapping" search on this forum and you'll sure find something.

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How do you order and where do you buy Mahle components for Kohler engines?

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Jerry,

The Mahle Piston or Piston style "D" is the 3rd generation Kohler piston used in the newer Magnum engines. They're manufactured in Germany and made of tougher material than the older Kohler pistons. They hold up to heat better and wear longer, too. And they weigh the same as a Kohler piston assembly. Mahle pistons have the same compression height as the K-series pistons. Mahle pistons just last longer under severe conditions, that's the only difference. You also have to get a stronger matching connecting rod if you go this route. Porsche engines use the Mahle brand too :D

I used a wire wheel brush on my electric drill and some emery cloth to do the carbon cleaning. Regarding lapping the valves it's pretty easy. Do a 'Valve Lapping" search on this forum and you'll sure find something.

Micah, Thanks for the info, much appreciated. I've worked on my tractors for many years but I've never been inside an engine yet. Except to replace a head gasket. I think I'm going to try to rebuild one this winter. That's why I'm gathering info now. Thanks again !! :woohoo:

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