Straight From the Horse's Mouth - The final chapter

Jump to content
Bob Nakon

12hp needs rebuild

Recommended Posts

Hello Gents,

 My C120 is running along, just feels like it's getting tired. It was rebuilt 12 years ago. New piston, rings, rod and gaskets. Now I think it needs a full rebuild, maybe bore .030 or whatever standard oversize is, and new internals. I live about 20 miles NW of Ann Arbor, MI. Does anyone know a machine shop not too far from me that could do this job? I don't know what I'm looking as far as cost goes on this. Maybe someone does?

 

Thanks, Bob

Share this post


Link to post
Share on other sites

I too have a 12 HP-smokes like a chimney.  Cost depends on whose parts go in.  For Kohler, upwards of $800 is what I was quoted.  There is a machine shop in Ohio, Kustom Lawn and Garden.  A complete remanufactured short block for WH K301 is $729 with a block trade in.  Have not decided to pull the trigger.  I already have over $800 invested in restoration of a C125 and with 4 other nice machines in the stable, I may just have to cut my losses and sell it as is to someone who has engine rebuilding skills

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the info Don. Mine isn't a smoker, it just seems like it doesn't have the power it used to have. I am not a engine mechanic for sure, but I am noticing a difference. I love this tractor, it never lets you down and it is our go-to machine for most jobs around the property. I take good care of it and I sure don't want to have it puke during the winter when we use it all the time. I'll keep looking for something close to me. Maybe I'll get lucky.

 

Bob

Share this post


Link to post
Share on other sites

Bob I too am from Michigan and I did a post on this subject.  Here is my post. There are others if you do a search on the main page.

 

 

 

 

  • Like 1

Share this post


Link to post
Share on other sites

Bob try calling Perry automotive and ask for Al, he runs their machine shop and does a good job.

517-625-3127 they are located on m-52 on the south end of perry.

  • Like 1

Share this post


Link to post
Share on other sites

Thanks for the leads guys. When you have this done do you take the engine to them intact, or do you tear it down to the short block?  I obviously have never done an engine before.

Share this post


Link to post
Share on other sites

have you checked the points and timing and could the carb need some tweaking. It would be worth trying to tune it up before calling for an expensive rebuild, if it's not knocking, smoking that bad or using a lot of oil, it may not need a rebuild. As I was writing this I recalled some of the tired old Kohler's that I had in the past, when starting no matter warm or cold you had to use full choke to get it started . just something to think about, good luck

 

 

 

 

eric j 

  • Like 2

Share this post


Link to post
Share on other sites

You guys honestly do not need to have "engine rebuilding skills" to do it yourself.  Its a matter of taking apart the engine in an organized way, aligning yourself with an honest machine shop (which can be tough these days) and letting them do the nitty gritty.  Then you simply put it back together following a set of directions.  These engines are very simple and very rewarding to have once complete. 

 

For those that have weak engines, start by decarboning the piston and head, cleaning and refresh the carb, and more importantly check the gap on the points.  Should be about .018" gap.  Any less and you loose power.  Upward of .020 will offer a tad more power but you may start to hear a combustion rattle.  

 

For old smokeys, a base gasket, a set of rings, and a head gasket will often give the engine several more years before a complete rebuild is needed.  In some cases I have found the rings were not staggered correct and they smoked heavily.  Yep this is not the professional way to do it, but it does work every time, at least by cutting back the oil burning. 

  • Like 1

Share this post


Link to post
Share on other sites

I love this place. It's like, ask and you will receive.  I can do plugs and points but I really don't know much about de-carboning the head and piston.  I'll have to get a new head gasket for sure.  What really worried me was I shut it down after running it with the Trac-Vac last weekend and the head was smoking. I see some oil around the seam where the head and block meet. Not a lot but just a dark area. So I'm wondering if it was running too hot or overworking. This tractor really gets a lot of use and we rely on it, maybe too much. It does most of the jobs on the property except for really heavy work. I have a IH diesel for that. I think I need a spare Wheel Horse for the times when this one is down.

 

By the way, can someone tell me how to de-carbonize the piston and head, and where is the best place to get a head gasket?

Edited by Bob Nakon
  • Like 1

Share this post


Link to post
Share on other sites
13 hours ago, Bob Nakon said:

I need a spare Wheel Horse

Welcome to out world!

5a0451e47ee53_1Horse-a-holic.jpg.ed8625a2b65a7147fa70edaceeaad92a.jpg

13 hours ago, Bob Nakon said:

tell me how to de-carbonize the piston and head, and where is the best place to get a head gasket

With the head removed and the piston at top dead center on the compression stroke (both valves closed) you can scrape off any accumulated carbon on the block and head. I run a setscrew into each head bolt hole in the block so they don't get crud down in them. I use a home made hardwood scraper to prevent gouging and scratching the metal. If I wasn't out of town I would add a picture of it.

Any good auto parts store will be able to furnish a new head gasket, or you can get them on :techie-ebay: if you wish.

You will need a torque wrench to tighten the head bolts and be sure to hot torque them after the engine has been run at normal temperature.

Share this post


Link to post
Share on other sites

If it's doing things like that after a hard work out - a decarbon and time spent to meticulously clean every fin on the engine will help a lot . If those fins start getting blocked it will overheat - it is after all an air-cooled motor and has to breathe . De-carbon is not that hard - you'll want a new head gasket (some re-use them) and most likely a carb base gasket to the block . Taking the tins off is not that hard nor is removing the head - just follow the engine manual . A wood or nylon scraper can be used to remove the oily carbon buildup on both the top of the piston as well as the cylinder head . A simple set of flat feeler gauges and a piece of glass will show if the head is warped or not or have a machine shop check it - should not exceed .003" or so out of flat . Put it back together with a known good torque wrench and follow the book - everything is quite well outlined in that engine manual .

 

At that same time , with it that far apart I'd have a set of breather gaskets on hand and set those valves - they are quite easy to set but pay very close attention to the book and how that breather goes together - otherwise it will push oil out like mad and leak everywhere .

 

Sarge

  • Like 1

Share this post


Link to post
Share on other sites

Thank you guys for de-mystifying the de-carbonizing. I can do that.  Am I hurting the engine by using it like it is until we are done Trac-Vacing?  I just did an oil change and we have 2 acres of leaves to get up before snowfall.

Share this post


Link to post
Share on other sites

It sounds like you have a leaking/blown head gasket.  There should be no oil leaking between the head and block.  I wouldn't run it like that.  You could make a bad situation worse.  If you change the points and condenser be sure to set the timing with a timing light.

 

Bill

Share this post


Link to post
Share on other sites

Sounds like you have a warped head. Lap it on some emery paper and it will show up.         Wayne

Edited by woodchuckfarmer

Share this post


Link to post
Share on other sites

Thanks for the response guys. I had an old Sun Gun but I haven't seen it in a while. It's an inductive pickup. Sounds like I need to do something with the Horse before I work it hard. I'll call the auto parts and get a gasket.

Thanks again.

Bob

Share this post


Link to post
Share on other sites
6 hours ago, Bob Nakon said:

I'll call the auto parts and get a gasket.

Thanks again.

Bob

If they have to order it, you might be better off getting one off fleabay... IIRC, they're under $10 for a decent one with the rim around the piston/valves opening. I just got a complete set of engine rebuild gaskets for under $25. missed a set for $22 because i didn't act quickly enough... lol

 

had them within 3 days as well.

Share this post


Link to post
Share on other sites
10 hours ago, Bill D said:

If you change the points and condenser be sure to set the timing

You may need to remove the flywheel cover tin to do this if there is no sight hole.

Kohler static_timing.pdf

5a058a46d45e3_Kohlerstatictiming.JPG.49333ab093291e68b796408f3e29cb5e.JPG

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Recently Browsing   0 members

    No registered users viewing this page.

×