Kohler SV735 Courage Dead at under 100 hours

Automan29

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Hello, I have a Husqvarna RZ5426 with a Kohler 26 V-twin courage. Last November, I loaned it to my in-laws and it hasn't run since. I was told that they turned it off, went inside for a break, came back out and tried to start it. It turns over fine but won't fire or sputter. I load it up and bring it home, clean out the carb, everything seems fine. On further disassembly I discovered all the push rods bent, after replacing them later found the intake valve on #1 having a hard time moving, replaced it too. Everything all back together, still won't fire and now it's shooting gas out of the exhaust. What did I do wrong, and how did it happen in the first place? Any help appreciated. Unit is an SV735-3031, serial #4214401613 with 96.1 hours.
 

ILENGINE

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One push rod I could see but not all 4. Seems like there is more to this story than shut off and then wouldn't restart. In law try to start with starting fluid, and backfired, Possible sheared flywheel key. The valve issue and bent push rod sounds like overheating. i think when you find the answer you will not be happy. Carb leaked fuel into cylinders and hydrolocked possibly.

I suspect that it wasn't shut off, it died with a violent stop.
 

cpurvis

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My guess is the cam and crank are no longer in time with each other and all four valves have collided with the pistons.

Probably a bad timing gear. Hopefully not plastic.
 

bertsmobile1

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All 4 pushrods bent is very very suspect as previously mentioned.
remove the spark plugs & rocker covers.
Put a pencil down one cylinder and rotate the engine slowly by hand.
Note when each valve opens & closes with respect to the position of the piston.
Both should be fully closed when the piston is closest to the head.
Note also how smoothly each pushrod goes in & out and how hard it is do move them.
Do the same on the other side.

I am with ILENGINE on this.
Think that either the inlaws smacks something very hard or ran out of oil.
Have a good look under the deck for signs of impact or stuff wrapped around the blade spindles.
Same with the front and back of the mower, look for impact damage.

Inlaws can be a big problem, particularly in your own bedroom.

How hilly is their property ?
Running along the side of a slope can cause the oil pump to spin in air & stave the engine of oil.
 

Luffydog

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I can't say that I ever had a problem with my in laws in the bedroom haha
 

cpurvis

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Your inlaws could very well be telling you the truth.

I was told that they turned it off, went inside for a break, came back out and tried to start it. It turns over fine but won't fire or sputter.

Back in the late '60's, GM (Pontiac) decided it would be a good idea to make cam sprockets out of fiberglass. That is the way people described the problem when the problem happened--car was running fine; shut it off; and no restart. Engine would spin, resulting in bent/broken pushrods.

It takes a lot of torque to get a camshaft turning, somewhat more than when running. If the timing mechanism is going to fail, that's a likely time for it to happen.

It would be interesting to see what those timing gears are made of and their condition.
 

bertsmobile1

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leaving one off manufacturing faults aside.
If there was a materials problem then a total failure would be a relatively common occurance.
However firstly , I have never heard of this before associated with SV engines
Secondly the starter motors used in these engines is very weak.
Most can not manage to overcome full compression so the thought that the starter was going to rip teeth off the cam drive gear then proceed to bend all of the pushrods y pounding the piston into open valves is a very very long bow.

The same thing happening wile the engine is running is a very different story.
So for instance the ACR falling off, slipping between the gears and striping teeth the the momentum in the engine pounding pistons into open valves is well within the realms of common occurences.
 

cmw

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I had this same engine in 25 hp (SV730) and had nothing but trouble with it. Yes, the timing gears are made of nylon or whatever so maybe they failed. You might look inside.

The Command is a great engine and I just had my first failure with one of those after many hard hours. It was also used and didn't look like it was the most cared for before I got it so figure it just lived its life. I have had two Courage motors and wasn't happy with either one. the SV730 was the first gas engine that i have ever seen runaway on all the oil it was burning like a diesel. Sometimes you could mow the yard with the key shut off the way the thing ran.

Conor
 
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