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Kohler Courage single cylinder engines.

#1

A

Auto Doc's

Beware of these engines, especially used. Kohler only showed they had the "courage" to build them to self-destruct.

Valve cover leaks.

The top cover bolts under the flywheel fan shroud loosen at under 100 hours on average. Some break off while other will contact the flywheel bottom side while running.

And the "final nail in the coffin" is the engine block will stress crack on the top right and leak oil constantly.


#2

Scrubcadet10

Scrubcadet10

Yep, the SV models have been beat to death on forums.
The cause of the crack in the block is the flywheel striking the bolts. Kohler China remedied this by adding loctite.
I will say my Courage has been a good engine, other than the carburetor needing rebuilt.


#3

ILENGINE

ILENGINE

Scrubcadet10 said:
Yep, the SV models have been beat to death on forums.
The cause of the crack in the block is the flywheel striking the bolts. Kohler China remedied this by adding loctite.
I will say my Courage has been a good engine, other than the carburetor needing rebuilt.
Click to expand...
Yep, they are still trying to beat the SV singles to death because of a few engines that had mistorqued top cover bolts, without locktite, and a few that broke the counterweight alignment rod which would break the bottom of the block dumping the oil. Later versions had gone 700-1000 hours easily. Anybody hear about failures on the 5400 series engines that was also a bucket style engine that replaced the SV singles. Didn't hear about those bolts coming loose or cracking the block.

Anybody remember the TH Triad DOHC engines. Seems nobody talks about that engine. The one were the timing belt cavity would fill full of debris damaging the belt, and required a debris eliminator hole on the bottom of the cover below the crankshaft pulley. Or if the engine overheated it would slide the steel cylinder liner down until the top piston ring would get above the liner and then the downward motion of the piston would drag the liner down into the crankcase resulting in it breaking both rods.. And Kohler paid for the Triad to Command conversion in Walker and Grasshopper mowers.


#4

Tiger Small Engine

Tiger Small Engine

Auto Doc's said:
Beware of these engines, especially used. Kohler only showed they had the "courage" to build them to self-destruct.

Valve cover leaks.

The top cover bolts under the flywheel fan shroud loosen at under 100 hours on average. Some break off while other will contact the flywheel bottom side while running.

And the "final nail in the coffin" is the engine block will stress crack on the top right and leak oil constantly.
Click to expand...
Also had starter issues. Also need to check the engine mounting bolts for tightness. Be sure to pull engine shroud and check top bolt bolts for tightness and that eliminates potential destruction down the road.

The Kohler Courage engines have given Kohler kind of a black eye I believe. Kohler, now Rehlko, makes a great engine, but the Courage has had some problems.


#5

ILENGINE

ILENGINE

Tiger Small Engine said:
Also had starter issues. Also need to check the engine mounting bolts for tightness. Be sure to pull engine shroud and check top bolt bolts for tightness and that eliminates potential destruction down the road.

The Kohler Courage engines have given Kohler kind of a black eye I believe. Kohler, now Relko, makes a great engine, but the Courage has had some problems.
Click to expand...
Never saw the starter issues on the singles. The twins are were the starter issues are. But that is due to using a starter without a supported shaft on an engine without ACR. Later Courage twins had ACR camshafts. And that engine is still in use but is now called the 7000 series.

And I still say the major issue with the Courage single with the leaking valve covers is that 2 piece cover. The 2 pieces vibrate separately and break the seal.


#6

Scrubcadet10

Scrubcadet10

ILENGINE said:
Yep, they are still trying to beat the SV singles to death because of a few engines that had mistorqued top cover bolts, without locktite, and a few that broke the counterweight alignment rod which would break the bottom of the block dumping the oil. Later versions had gone 700-1000 hours easily. Anybody hear about failures on the 5400 series engines that was also a bucket style engine that replaced the SV singles. Didn't hear about those bolts coming loose or cracking the block.

Anybody remember the TH Triad DOHC engines. Seems nobody talks about that engine. The one were the timing belt cavity would fill full of debris damaging the belt, and required a debris eliminator hole on the bottom of the cover below the crankshaft pulley. Or if the engine overheated it would slide the steel cylinder liner down until the top piston ring would get above the liner and then the downward motion of the piston would drag the liner down into the crankcase resulting in it breaking both rods.. And Kohler paid for the Triad to Command conversion in Walker and Grasshopper mowers.
Click to expand...
Never knew of the Triad. but wow.
I've always felt overhead cams were kind of pointless in small engines. flat tappets or hydraulic lifters and pushrods have worked fine for 100 years


#7

Scrubcadet10

Scrubcadet10

ILENGINE said:
Never saw the starter issues on the singles. The twins are were the starter issues are. But that is due to using a starter without a supported shaft on an engine without ACR. Later Courage twins had ACR camshafts. And that engine is still in use but is now called the 7000 series.

And I still say the major issue with the Courage single with the leaking valve covers is that 2 piece cover. The 2 pieces vibrate separately and break the seal.
Click to expand...
My courage is valve cover is leaking.... i wish i knew someone who could replace it for me, LOL :ROFLMAO:


#8

A

Auto Doc's

Hi ScrubCadet10,

I think the small engine overhead valve design was a delayed bleed over from the automotive industry, it just took longer period of time after the flat head automotive engines went extinct.

For small engine equipment the flat head engines were much more reliable for the end user, that is likely why they were eliminated.

Declining sales and reliability go hand in hand and that's bad news. Manufacturers make more much money selling more "whole goods" products than they do a reputation for longevity. (Think Clinton, Lawn Boy and other engines that are now long gone)

By making overhead valve engines, there are more moving parts which increases wear factors and reduces longevity. It has nothing to do with the environmental or political sales pitches, it's all about money.

Adding design complexity also makes them more expensive to repair in the future. High shop labor rate costs and expensive parts just adds up to the customers buying more new machines in the future.


#9

A

Auto Doc's

Scrubcadet10 said:
My courage is valve cover is leaking.... i wish i knew someone who could replace it for me, LOL :ROFLMAO:
Click to expand...
Ditch the cork design and make your own out of pressed paper gasket material. It will last much longer.


#10

ILENGINE

ILENGINE

Scrubcadet10 said:
Never knew of the Triad. but wow.
I've always felt overhead cams were kind of pointless in small engines. flat tappets or hydraulic lifters and pushrods have worked fine for 100 years
Click to expand...
This engine used lost foam casting technology. The melted aluminum would dissolve the foam and would cast the upper half of the crankcase down the middle of the crankshaft bearing surfaces. So the upper half of the crankcase, cylinders and heads were cast as one piece. The cylinders were bored and because the heads were non removable like the Honda GC engines the cylinder liners were pressed in from the crankshaft side. Valves had to be installed prior to piston insertion into the bore.

The OHC cams had to be timed also with the crankshaft with a special holding fixture when the timing belt was replaced or installed. This engine was bragged up due to the fact that it used something like 100 less parts than a standard OHV engine. The engine in the end turned into a multi-million dollar fiasco before it was over.

The only good thing about the engine was it was a non-interference engine. Meaning the valves didn't hit the piston when the belt broke.


#11

B

BGS Mex

Auto Doc's said:
Beware of these engines, especially used. Kohler only showed they had the "courage" to build them to self-destruct.

Valve cover leaks.

The top cover bolts under the flywheel fan shroud loosen at under 100 hours on average. Some break off while other will contact the flywheel bottom side while running.

And the "final nail in the coffin" is the engine block will stress crack on the top right and leak oil constantly.
Click to expand...
I had this happen a few years ago that did crack the block. I Tig welded the crack and reinstalled the cover plate as attached shows. Torqued to spec and used blue loctite.

Attachments


  • Oct. 23 2023 Closure Plate Fastener Bushings.pdf
    602.8 KB · Views: 6


#12

Scrubcadet10

Scrubcadet10

creative fix right there!


#13

B

BGS Mex

Scrubcadet10 said:
creative fix right there!
Click to expand...
Thanx; Still working great, no loose bolts nor leaks


#14

W

Wrenchit

ILENGINE said:
Yep, they are still trying to beat the SV singles to death because of a few engines that had mistorqued top cover bolts, without locktite, and a few that broke the counterweight alignment rod which would break the bottom of the block dumping the oil. Later versions had gone 700-1000 hours easily. Anybody hear about failures on the 5400 series engines that was also a bucket style engine that replaced the SV singles. Didn't hear about those bolts coming loose or cracking the block.

Anybody remember the TH Triad DOHC engines. Seems nobody talks about that engine. The one were the timing belt cavity would fill full of debris damaging the belt, and required a debris eliminator hole on the bottom of the cover below the crankshaft pulley. Or if the engine overheated it would slide the steel cylinder liner down until the top piston ring would get above the liner and then the downward motion of the piston would drag the liner down into the crankcase resulting in it breaking both rods.. And Kohler paid for the Triad to Command conversion in Walker and Grasshopper mowers.
Click to expand...
!00% on that!
The bucket series is easier to work on, at least for me, anyway.
Always liked to do the tear-downs at Kohler school on these.
Another of Kohler's bright ideas was,
Command series with the nylon of a plastic governor ball cage.
Easy to diagnose, pull the dipstick, and if the bottom is baked, with a dark brown color, the governor ball retainer is either shot or nearing the end of its life due to extreme overheating.


#15

S

slomo

Auto Doc's said:
Ditch the cork design and make your own out of pressed paper gasket material. It will last much longer.
Click to expand...
One can use a cereal box to do just that. Also hit it with some Permatex High Tack gasket sealant. Works like a charm.
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