Questions about markings on a Kohler piston.

[lonnyb]

I took the head of a 10hp Kohler, K-241as. as the motor has been giveing me some troublr lately.
I found the letter A stamped into the top of the piston and also into the block under the head gasket.
Now I have seen markings of std, standard bore, and 10, 20, and 30 as to indacate size of a rebore and larger piston.
I have neve come across a marking like this befor.

My questions are this, could this be an indacation of standard bore?
Or possable a re-hone and oversize rings with a standard size piston?
Or??

The piston seems to be tight in the bore at the top and bottom of the travel as I can not wiggle it side to side in any direction and the walls look nice and shiney, but no sign of a cross hatch hone pattern. There is a small ring of carbon buildup at the very top of the cylinder also.
Engine smokes at start up and after an hour or so of hard work starts to blow blue/gray smoke out the breather cover. Will use about half a quart of oil every 5 tanks of gas.
I want to keep my cub cadet 102 running as long as possable, but due to the lack of any small engine rebuilders around where I live, I have not found any place to take it in to have it checked out to see if it needs rebuilding.

[Fordlords]

I don't know about the markings, but from what you describe the engine is giving every indication it's due for a rebuild. I'm almost sure the 10 HP K241 can be bored all the way up to the size of the 12 HP K301, so even if it has been rebuilt once, having it done again should not be any worry. If the tractor is in generally good shape, the engine is worth getting overhauled, look to spend about $600.00 for a decent job. Looking at where you are at the best bet will probably be to remove the engine from the tractor and take it in to St Paul where there should be plenty of shops who will rebuild it and give you a small warranty. Another option would be to replace the short block with a brand new one, about $850.00, (saves the costs of rebuild labor, and you have essentially a new engine) or complete new engines are avaliable for about $1200.00.

-Fordlords-

[Eugene]

The letter "A" is probably a factory marking to indicate which size piston to install in the cylinder bore. Factories used letters to adjust for very minor variations in cylinder bores.

As far as the cost of an engine overhaul. I do my own overhauls on single cylinder Kohlers. Typically the overhaul costs me about $80.00. That's for a new set of rings, gasket set and an exhaust valve.
Add about another $30.00 for a new piston if you need to enlarge (bore out) the cylinder.

The most expensive part to replace or machine is the crankshaft. If the crankshaft is bad, look for another junker parts engine.

Depending on your mechanical abilities. Purchase the required small engine tools and overhaul the engine yourself.

Eugene

[Fordlords]

Yes most of the money involved in a rebuild is for the labor. But if the block needs to be overbored and honed, which is most likely, or the valves and seats need grinding, it will need to go to a machine shop for that. If one can handle the assembly tasks themself on the refurbished block, a lot of money can be saved on the rebuild. I once just put a new ring set on a Tecumseh that was smoking and using oil, and got a couple more years out of it.

-Fordlords-

[wdeturck]

I think that engine was rebuilt and the person who did it marked the piston and block so he got them back the same way. I mark engines with center punch marks to make sure they go back together like they were(not as important as on multi cylinder engines) but I also mark the rods & caps which usually have marks but I don't need a manual to find them.

Just got back from Red Power What a great 4 days.

[Dave (69 lo-boy)]

As far as the cost of an engine overhaul. I do my own overhauls on single cylinder Kohlers. Typically the overhaul costs me about $80.00. That's for a new set of rings, gasket set and an exhaust valve.
Add about another $30.00 for a new piston if you need to enlarge (bore out) the cylinder.

The most expensive part to replace or machine is the crankshaft. If the crankshaft is bad, look for another junker parts engine.

Depending on your mechanical abilities. Purchase the required small engine tools and overhaul the engine yourself.

Eugene

Hey Eugene, those numbers sound more like it to me, I was wondering what could possibly be so expensive in a Kohler that would make a rebuild cost $600.00, the last V-8 I rebuilt cost about $400.00 and had about 8 times as many parts.
Dave

[Leadfoot]

As far as the cost of an engine overhaul. I do my own overhauls on single cylinder Kohlers. Typically the overhaul costs me about $80.00. That's for a new set of rings, gasket set and an exhaust valve.
Add about another $30.00 for a new piston if you need to enlarge (bore out) the cylinder.

The most expensive part to replace or machine is the crankshaft. If the crankshaft is bad, look for another junker parts engine.

Depending on your mechanical abilities. Purchase the required small engine tools and overhaul the engine yourself.

Eugene

Hey Eugene, those numbers sound more like it to me, I was wondering what could possibly be so expensive in a Kohler that would make a rebuild cost $600.00, the last V-8 I rebuilt cost about $400.00 and had about 8 times as many parts.
Dave

I don't know about rebuilds costing $80 + $30...........

A couple of years ago a Kohler dealer let me see their price list, and a .010 piston and ring set for a K301 was $91.xx list! However -his cost- was $15.xx!!!!!!!!!

A 're-manufactured' 350ci Chevy is right around $900 w/exchange here, but it cost me $601 to get a K321 completely machined and rebuilt last November................for some reason the Genuine Kohler parts are big time $$

[Fordlords]

It is sort of crazy to see what these small engines cost when compared to common automotive engines. A new Kohler Command 25 twin cylinder short block costs every bit the $700.00 as a brand new short block Chevy V8. The new Honda engine I put in my 682 was $1350.00, I could easily put a hopped up new Chevy crate engine in my '81 Malibu for that

If you think the small engine prices are out of whack, just go and look at marine or motorcycle engines and parts where the rip-off is squared!

I was just stating before that most people I know who have had an outside shop completely rebuild a Kohler K engine with all new wear parts and had the cylinder, crank, and valves properly machined along with all new seals and gaskets spent between $500-700 for the work. If this is done right, what is a 30+ year old engine can give another 30 years of service. List prices for the K241 are $1376.73 for a complete new engine, and $861.25 for a new short block, so with the cost of internal parts ($109.10 for a piston and ring kit, $95.36 for a cam, valves and tappets about $22.00 ea, $40 for a gasket set, and $248.63 for a crank if needed) it's easy to see where the $500-700.00 for the rebuild is realistic once the labor for assembly and machining is added in. Consider that Kohler no longer manufacturers K series cast iron engines, so as the supply diminishes on the leftover engines and parts the prices go up.

I worked as a motorcycle mechanic years back, and it was not uncommon for people to come in the shop with a blown engine on their bike and the cost to rebuild it would be more than half the original price of the bike so they would just junk it I highly doubt the entire new Cub Cadet 102 tractor cost near the $1376.00 just its engine costs today.

-Fordlords-

[rvbarkley]

Just rebuilt a K-241 myself, .020 over piston/rings/with rod and gasket set off e-bay was $80.00. Add $35.00 to have it bored then a few more $'s for misc. = less than $125 complete. (valves were fine but did re-lap).

[Paul B]

Lonnyb
That "A" probably means that engine had a .003 oversize piston in when new. In later years, Kohler stamped the piston and the block under the head, with .003 to indicate the engine was an oversize rather than standard, but if it is an older K241, the "A" may mean the same thing. I'm just guessing, but if you mike the piston and the top of the bore, it should tell if it is .003 over. Standard was 3.251.