broken bolts

[Vulnavia]

Cub cadet kohler courage 18, started smoking yesterday and leaving a trail of oil. Broken/loose bolts on the upper case. Not the first or second or third time this has happened. This time the gasket "broke". Ordered a new one and some bolts. Always used genuine kohler and blue loctite, torqued them to spec. Bought new, 350hours. I'm pretty easy going on stuff and can repair just about anything. Have had nothing but problems with this engine. I will never buy another kohler product. Any ideas?

Thanks,
Will

 

[Rivets]

Experience tech have a phrase for those engines. “It take courage to buy a Courage engine”. Sounds like you’ve decided to repair it, which those same techs have done when the customer wants to go that route. I’ve done so myself, but have a warning to those customer’s to try to alleviate the problem in the future. I tell them at the beginning of each season have someone, if you can’t do it yourself, to remove the shroud and check the crankcase bolts making sure they have not come loose. If you don’t have one this manual may help you out. https://www.mymowerparts.com/pdf/Ko...urage-SV470-SV480-SV530-SV540-SV590-SV600.pdf

 

[bertsmobile1]

IT is usually the 4 bolts near the cylinder that come loose
If your have come loose multiple times then the threads may be damaged so I would suggest helicoiling them
Use red loctite on the helicoils
BEcause the inserts are stainless they should not need any anti vibe treatment but if they do come loose then something weak like pipe sealant would be the way to go .

 

[Vulnavia]

Experience tech have a phrase for those engines. “It take courage to buy a Courage engine”. Sounds like you’ve decided to repair it, which those same techs have done when the customer wants to go that route. I’ve done so myself, but have a warning to those customer’s to try to alleviate the problem in the future. I tell them at the beginning of each season have someone, if you can’t do it yourself, to remove the shroud and check the crankcase bolts making sure they have not come loose. If you don’t have one this manual may help you out. https://www.mymowerparts.com/pdf/Ko...urage-SV470-SV480-SV530-SV540-SV590-SV600.pdf

Was hoping for a simple fix, was just dreaming. I'll start saving for a new lawn tractor.
Thank you for the repair manual and the advice.
Will

 

[Vulnavia]

IT is usually the 4 bolts near the cylinder that come loose
If your have come loose multiple times then the threads may be damaged so I would suggest helicoiling them
Use red loctite on the helicoils
BEcause the inserts are stainless they should not need any anti vibe treatment but if they do come loose then something weak like pipe sealant would be the way to go .

Yes that's them. Threads are a little loose.
Thanks,
Will

 

[Tiger Small Engine]

Yes that's them. Threads are a little loose.
Thanks,
Will

Please don’t condemn all Kohler engines. Kohler makes a great product, just not the Kohler Courage, especially the single cylinder. Usually you can catch the loose bolts on this bucket style engine sump before they do damage (preventative maintenance). However, because most owners, and some mechanics, never remove the engine shroud for cleaning, it can and will lead to catastrophic failure. Check your engine block for cracks since your engine is now leaking oil.

 

[Vulnavia]

Have had a lot of engines over the years, never had to "nut and bolt" as they say unless it was a race engine or retorquing after warm up-cool down. Should have know since they came loose before. I will have to change my way of thinking. I hope I don't find any cracks. Any ideas for a replacement engine?

Thanks,
Will

 

[bertsmobile1]

When you get inside the engine it is obvious that it was originally designed to have a forged crank shaft like the Commands because the crankshaft is about 1/2 the cost of the engine so using a common crank brings in massive economies of scale plus reduces inventory items
However some where in the process they switched to the much cheaper to make malleable iron cast crankshaft
This of course is near double the weight of the forged one so the engine balance was way out of wack
This caused problems with the counter balance system which was changed at least 3 times till they got it right
Now the vibration problem does not manifest itself in every engine and as far as I can see is both engine & useage dependent
Husqvarna dumped thousands of their "problem child" fitted with this engine down here rather than sell them in the USA and create a massive brand problem for them .
Oddly enough the Kohler crack down here seems to be limited to Husqvarna ( and other AYP clones ) as the Ariens Mini Zooms seem to be unaffected
In my service run about a 1/4 of the Courage powered Huskies seem to suffer from bolt loosening and once loktited all have been fine .

 

[Vulnavia]

I saw the crank and thought to myself, it's a bit much but there must be a reason. Did you use red or blue loctite ?
Thanks for the Information.

Will

 

[bertsmobile1]

Blue is fine, a star washer works well as will replacing the bolts with flanged & toothed bolts .
For some weird reason the std split spring washer did not work as well
IT is just a 3rd, 4th harmonic etc thing
On mowers that come in every coupe of years I put a centre punch mark facing out on all of the bolt heads so I can do a quick visual rather then cracking & re-torquing them
The give away about the crank size is the crankcases and the boss where the crank runs, way too thin for the crank
Then there is the sheer size of the counter weight, near twice the size of the B & S ones .
It was a mystery till I pulled down a command engine & saw it had a forged crank that had actually been twisted & upset ( Metallurgist in a former life ) that the penny dropped .