1976 K341 Overhaul - Worth It or Not?

[The Tuul Crib 7,332]

19 hours ago, roadapples said:

Save that sweet 16....

[Pullstart 59,733]

Hey @HappyHillbilly,  to !!!

 

It already sounds like you’re figuring out that you’re hooked to us nutty folks for good!  As I’m reading along I’m thinking “just pull the head and see if anything’s moving”.  At the very least it’ll be good to inspect / clean the top end.  At that point, you can check the moving parts by spinning the flywheel by hand.  

[HappyHillbilly 86]

16 hours ago, pullstart said:

Hey @HappyHillbilly,  to !!!

 

It already sounds like you’re figuring out that you’re hooked to us nutty folks for good!  As I’m reading along I’m thinking “just pull the head and see if anything’s moving”.  At the very least it’ll be good to inspect / clean the top end.  At that point, you can check the moving parts by spinning the flywheel by hand.  

 

Richard - thanks for that leak-down info. If my friend doesn't have one, which I'm sure he does, I'm just the guy for making one.

 

"pullstart" - Thanks for the welcome! And, yeah, I'm feelin' right at home here already. I think I'm starting to get WH addicted already. Haha!!!

I hope to have the head & cover plate off today & see how everything looks.

 

Edited March 6, 2019 by HappyHillbilly

[953 nut 51,721]

4 hours ago, HappyHillbilly said:

I'm starting to get WH addicted already. Haha!!!

[HappyHillbilly 86]

I got the head & breather plate removed today. Man, it's not a pretty sight.

I know one of the valves is stuck - I believe it's the exhaust valve. Piston & other valve move freely when turning flywheel by hand. I'm going to try to borrow a bore gauge tomorrow. As a former machinist I know you can't get an accurate I.D. measurement with calipers, but, I tried anyway and got a fairly steady reading from various points around the cylinder of 3.7685". Looking at the Kohler manual that's a wee(?) bit over the margin. Cylinder wall looks good, though. But my wife says that looks ain't everything. (she found out the hard way)

 

 

Edited March 7, 2019 by HappyHillbilly
Grammar

[oldredrider 2,547]

It is a bit crusty. Should buff out! Seriously, typical of a motor that has set for a long time. 

[bc.gold 3,399]

IMO you made the right choice to overhaul.

 

New vs. “Seasoned” Blocks
It used to be that no self-respecting performance enthusiast would consider using a new block. This 
wasn’t simply a matter of money. New blocks just didn’t make as much power as well seasoned used 
blocks. Engine blocks, like football quarterbacks, get better with age. In the case of a block casting, 
countless cycles of heating up and cooling down help to “season” the metal. When a block is first 
cast and then machined on the assembly line, it develops internal stresses. The heating/cooling 
cycle allows these stresses to “relax,” until finally the block becomes dimensionally stable. In the 
opinion of many top ranked racers, an engine does not achieve maximum power output until it has 
been honed three or four times; it takes that long for the cylinder bores to settle down and hold the 
perfectly round shape that promotes a “tight” ring seal.

[HappyHillbilly 86]

Thanks, "oldredrider" & "bcgold".

 

I was able to get the valve to move up & down with little force but it doesn't look like it's gonna smooth out on its own that way. I'm taking engine off tractor this afternoon and get it inside to clean it up & disassemble it.

I can hear Conway Twitty singing "I can tell you've never been this far before. Bum, bum, bum bum,,," Haha!! But I'll make it.

 

Question - What's the best way the pull out the sticky valve without a special tool? It's not gonna take a LOT of pressure to get it out, I just can't twist or pull it by hand.

[oldredrider 2,547]

Penetrating oil like Kroil or BG Inforce should loosen up the carbon build up on the valve stem. Patience is your friend! It will come out when the carbon breaks down. 

[HappyHillbilly 86]

14 minutes ago, oldredrider said:

Penetrating oil like Kroil or BG Inforce should loosen up the carbon build up on the valve stem. Patience is your friend! It will come out when the carbon breaks down. 

 

Thanks! I'll get me some of one of those. PB has worked so far but it looks like it's just not strong enough for this as I sprayed it good last night. Appreciate it!

[ebinmaine 63,157]

I'll second the patience thing.

 

PB is ok for some things but I've gone away from using it.

I've had great success with Kroil. Also the old Liquid Wrench. $4-$6 a can is really tough to beat and it works well statistically and in the field.

 

Penetrating oil is like many other things where each of us can have a pretty wicked brand loyalty.

 

 

Glad to see you are attacking this Engine and Tractor.

Keep asking questions....

[HappyHillbilly 86]

Thanks, Eb. 

I “hate” bothering people & I’m so stubborn that I’ll spend hours trying to figure it out myself or search online before asking anyone. 

 

I’m getting in over my head but I can swim. With y’all’s help I feel a bit more confident. Slow & leery, but somewhat confident. 

 

Y’all have a great day!

Mike

[953 nut 51,721]

Take a look at this thread, it has a lot of great information and even though it is a smaller engine the process is the same.

 

[clueless 2,898]

Blaster small engine tune up in a spray can, been around for years. I've used it for years on small engines and outboards after they sat for a season or two. Last time I clean the carbon of a kohler head, valves and piston i was out of Kroil, shot some of this stuff on and let it sit awhile, used a plastic scraper and a small brass brush, cleaned up nicely . It's made by the same people who make PB Blaster, just another cheap tool to add to your arsenal if you work on small engines.

[HappyHillbilly 86]

22 minutes ago, 953 nut said:

Take a look at this thread, it has a lot of great information and even though it is a smaller engine the process is the same.

 

 

 

Thank you! I bookmarked that thread.

 

8 minutes ago, clueless said:

Blaster small engine tune up in a spray can, been around for years. I've used it for years on small engines and outboards after they sat for a season or two. Last time I clean the carbon of a kohler head, valves and piston i was out of Kroil, shot some of this stuff on and let it sit awhile, used a plastic scraper and a small brass brush, cleaned up nicely . It's made by the same people who make PB Blaster, just another cheap tool to add to your arsenal if you work on small engines.

 

Thanks!

 

Question: I checked the head for flatness. If I'm not mistaken manual says .003" tolerance - Mine has a few places that are between .003 - .004". That should be OK, 'eh?

[Ed Kennell 35,800]

I would  rub the head perfectly flat by rubbing it on a piece of 320 or 400 grit emery cloth taped to a piece of glass. After the head is cleaned of all carbon, paint it with magic marker or machine bluing, then   rub it in a figure 8 pattern on the emery cloth till all the high spots are removed.

[Sarge 3,462]

Look up a home penetrant called "Ed's Red" - that will quickly break down the carbon in that valve so it can come out easily and will also dissolve the buildup of material on top of the piston. Quite cheap to make decent sized quantities, but be aware of flammability and it will easily evaporate the acetone when you try to store it.

 

Sarge

[richmondred01 2,205]

Standard bore for k341 is 3.750

Ive rebuild countless k series in this shape.

yes the k341 is worth Rebuilding. In my opinion the k341 and m16 were the best single cylinder engines ever built.

bore the cylinder, most likely the crank will need to be turned, grind the valve seats and plain the head. 

Replace with quality parts and your engine, at least in my area, should be worth 1000.00. 

[HappyHillbilly 86]

21 hours ago, Ed Kennell said:

I would  rub the head perfectly flat by rubbing it on a piece of 320 or 400 grit emery cloth taped to a piece of glass. After the head is cleaned of all carbon, paint it with magic marker or machine bluing, then   rub it in a figure 8 pattern on the emery cloth till all the high spots are removed.

Thank you, Ed! That sounds like a good idea & I'll do just that.

 

3 hours ago, Sarge said:

Look up a home penetrant called "Ed's Red" - that will quickly break down the carbon in that valve so it can come out easily and will also dissolve the buildup of material on top of the piston. Quite cheap to make decent sized quantities, but be aware of flammability and it will easily evaporate the acetone when you try to store it.

 

Sarge

Thanks, Sarge! Unfortunately I can't use Ed's Red - it says in the Safety Notice; "Keep them (chemicals) away from pets and stupid people." Haha! that rules me out. Seriously though, gonna mix me up some. 

 

1 hour ago, richmondred01 said:

Standard bore for k341 is 3.750

Ive rebuild countless k series in this shape.

yes the k341 is worth Rebuilding. In my opinion the k341 and m16 were the best single cylinder engines ever built.

bore the cylinder, most likely the crank will need to be turned, grind the valve seats and plain the head. 

Replace with quality parts and your engine, at least in my area, should be worth 1000.00. 

Thanks, "richmondred01". I'll borrow a bore gauge and hope & pray that this one's been bored .020" over and isn't out of round or specs. With my caliper readings being 3.7685" I just "might" be in luck.

 

Ya'll have a great day!

HH

[richmondred01 2,205]

You can go .030.

you have to measure the center of the bore in several places.

[HappyHillbilly 86]

OK, folks - before I mess something up - how do I get this (brake/pulley?) off? 

Thanks!

[richmondred01 2,205]

That’s the pto disc.

remove the four bolts and retainers, disc may be tight but will slide off. 

The bearing race can be difficult at times. Use heat and pb blaster in key way.

 

 

[richmondred01 2,205]

Then use a three jaw puller to remove the drive pulley.

don't forget the Allen set screws.

[953 nut 51,721]

Speaking of Allen set screws, Wheel Horse sometimes used two of them. The first one is down tight on the key and the second one is tighten on top of it as a lock to keep the first one tight.

[HappyHillbilly 86]

Thanks for your promptness! Good timing. I was stopped at a traffic light one block from auto parts store to get a pulley puller because I don’t know what happened to the one I had.

 

Richard - Looks like there are 1-2 allen screws behind that disc. There are 2 holes. 

 

Thank you two!!!