General cost to rebuild a M18

[dodge trucker]

I put this in "general" because this engine isn't off of, and isn't destined for a Cub machine. I originally started this post at the end of the other recent M18 thread under "Kohler engines" but I didn't want to muddy the waters of that thread.
I just picked up a M18 via CL, at what I thought was "a too cheap to pass up" price" probably cost me about 2/3 in gas, what the guy wanted for this engine. He took it from a WH tractor when it started eating oil. Original owner of said WH machine. He repowered his tractor, with a brand of engine that I don't care for. He sold me this one for a whole $25.
Said it was still running when removed, plan to try to fire it up and evaluate things before I tear it down. I want it as a backup engine for my snowblower tractor. but its KT19 is still holding its own, so I don't have to be in a hurry.

Anyways I looked around on Feebay and didn't see a "kit" shown, like they sell for the cast iron singles. Am I going to have to buy pistons and gaskets piecemeal-style for this series of engine?
I am going into this teardown expecting to have to take the jugs in to be bored, whole works. For purposes of this topic I am mostly interested in "parts" prices.

As far as Kohler suffixes go, this is a M18 QS. I know that Q means "quiet model" but does that mostly pertain to the exhaust? In the singles, I thought the engines with a Q also had the grenade gears, or no?
did any of the opposed twins have these?

[ol'George]

M-18 does not have balance gears, they are so smooth being an opposed twin,
they don't need them.
Before you decide it needs rebuilt, run it thoroughly and evaluate it.
I've seen something as simple as a dime size rubber breather valve
in the valve cover gone bad, causing oil usage.
As far as gaskets, there a few but none on the crankcase halves or cylinder jugs.
as they use sealant.
Aftermarket pistons/rings and rods are available from Bat4kids on ebay.
Genuine kohler pistons/rings/rods when available, are very costly.
I do prefer kohler for the 2 seals on the crank but cannot speak badly for stens as I have never used them, I do use stens Head gaskets, about $13 ea.
as far as cost, it is going to vary with whats needs done.
They was a fellow who sold rebuilt blocks with cylinders for about $1000, but I think a diligent/capable person could do it for $500 himself.
your results will vary.
Do check the crankshaft for length and size as I don't know if a WH is the same as a cub.

[dodge trucker]

yup I had a bad breather on my KT19 and that engine was an oil eater when I got it too... that one has almost 1800 hours on it and doesn't use oil any more. and I have never rebuilt that one, just replaced the breather and crank seals. This engine has 1500ish hours, seller still had the machine and has only put a few hours on it since he replaced the engine with a Honduh (yuck)

Figured that now's the time to go through it, do it now once and for all, before I need it..... but I do plan to try the breather, seals and head gaskets like what worked for me on the KT19 before I pop it apart....
I have a pretty good idea what the machine shop labor will cost, I know that I won't know how bad things are until I start to take it apart, but the price on a standard piston/rings isn't much different from the price of 10-over or even 20-over....
nother question might be a stupid one/... started scouting on Fee bay a bit. I see ring sets listed as fitting either this engine OR a K241 (10hp) so if this engine does have the same bore size as a K241 does that mean that pistons from a 214 would fit this engine? (with that said I never did look up the stroke of either this engine or the K241 I know that stroke will have a lot to do with what else "might" work, just looking at possible options here)

also you guys might not like this, thought I mentioned it before, but at this point the tractor I have that I was thinking of to drop this engine into isn't a Cub either.... but if something pops up before I get this engine back in shape, it might wind up in one. as far as crank diameter, I am not too worried as I can get a clutch hub with a different I.D. to match this crank if need be. or if this one is smaller I can get a different bushing or bearing to fit the clutch that I have. it is an electric PTO setup.
I know that I ain't the only one here that plays with more than 1 brand of tractor, right?
Thanks George for your input.

[ol'George]

The M-18 uses Mahle forged pistons, 16, 17, 18. hp opposed twin use same
pistons.
I have no experience piston swapping other than proper applications.
Your engine number will tell you many things, like Valve angle, *30 vs *45
also if you use a gasket or sealer on the closure cover.
Those engines are tougher than a lot of ppl give them credit for if cared for properly.
A higher hour engine will have oil wetness in the air cleaner, but not dripping.
A low hour engine will be dry or just a visible coating ( with a properly working vent flapper or poppet valve)
#90 compression is acceptable.
Follow & download the manual if you have not done so.
Also make a scribe mark on the cam plug BEFORE when/ if you split the cases,
as it insures that it is clocked back the way it was punched/installed originally.
Just good insurance that it does not leak, and use a new "O" ring.
I dislike silly cone and prefer to use Yamabond or hondabond designed for crankcase sealing.
More is not better, small oil passages are easily plugged.

[dodge trucker]

model... M18QS
serial 1631802236
and thanks for the input.
I see somebody moved this, OK with me.... I originally was gonna put this here, and I know it's 'really close to" the engine used in many Cubs, I put it where I did because it's not a "cub engine"........

[riesedesperado6170]

Kustom Lawn and Garden sells reman long blocks i got one and love it. they were 1400.00, but that was 4 years ago

[DeltaCub]

Originally Posted by riesedesperado6170

Kustom Lawn and Garden sells reman long blocks i got one and love it. they were 1400.00, but that was 4 years ago

Here is the link to Kustom's shop.

http://shop.kustomlawnandgarden.com/

[john hall]

I only did a "top end" rebuild on mine. Sent the jugs to have valves ground. It was about $50 for that. For another 40-50 I could have got it bored, but mine measured in spec so I put in new aftermarket pistons (scoring on old ones), maybe 30-40 each. Paid about that much for an aftermarket gasket set--it may have come with seals. Add in 2 new plugs, motor oil, oil and air filter and I was good to go--other than some carb issues. I faced the heads myself. The reason I didn't do a full rebuild was it was way to expensive for no more than I run the mower. Used it a year (more actual use than we anticipated) and no problems.

[DieselDoctor]

I found the biggest expense during the recent rebuild of my M18 was the cost of the valve guides and valves. The early style exhaust valve is obsolete and every seller that still has them knows that. I paid $42 for a valve and $28 each for guides. The gasket set, rings, and pistons were very reasonable aftermarket stuff.

[dodge trucker]

well, within a few hours' drive there are 2 M20s on CL, one is $400 the other is $425...both claim they will demonstrate that they run before you buy, etc.... but no idea how many hours, what kind of maintenance (if Any) over the years, etc.... buy one and have it last 1/2 a season (no way of knowing going in) then have to repeat the process of looking for another or rebuild at that point... I have this M18 here now, have about $40 into it including gas to go get it, so if I can rebuild it for a reasonable price, I figure I'm ahead as compared to what I currently see on CL....
jugs will go in to machine shop, depending on what I see I may do just the "top end" option, will have to see what it looks like, on other small engines I have had the machine shop make me a valve guide out of something more commercially available, (their call, not mine in that case), cut down to fit for minimal outlay and have worked just fine, don't yet know if that might be possible with this particular application....though I know that would be a small portion of what would be needed to do a proper overhaul....