Courage twin slow cranking

[Mr Mower Man]

I have a Kohler courage twin in the shop that is cranking hard. (SV720-0010, w/ 611 hours) Battery fails a load test, but even with a new battery (over 300 CCA), it doesn't crank over like it should. I'm used to adjusting valves on Briggs engines, but I never seem to have to do that on these Kohler engines. So I look in the service manual and it's supposed to be checked/adjusted every 200 hours. This engine has never had it done. It acts just like the compression on the compression stroke is too much. So I plan to check the valve clearance and make sure it's .005", per the service manual.

But I'm not familiar with these Kohler Courage twin camshafts. Do they have an ACR mechanism like some Briggs, that break off? Or is it a "bump" machined into the cam lobe?

[hanz63]

This doesn't have a separate arm such as an Intek single so it is more in the grind such as an Intek twin. Once you have done your electrical due diligence and lash hopefully you will see an improvement. The starter itself has been changed for a ~ 20% increase in torque and will normally fix them.

[Mr Mower Man]

Yes, I'll use some jumper cables on the negative terminal to ground, and from the positive terminal to the starter terminal, and see if it acts the same, just to make sure it's not a wiring issue. I suspect the starter too, since these Courage starters seem to wear out faster than most others. But the most obvious thing to me was the compression.

[bgsengine]

They do have an ACR but if you gotta get into the camshaft side of things, those bucket engines are hardly worth the work.

Also, a simple enough means of diagnosing that hard crank would be a compression test - you would wanna see around 80-90 PSI or thereabouts , showing ACR is working (non-working ACR or valves out of spec, you might see compression as high as 140 - 160 or more)

If compression seems in spec, I'd suggest a voltage drop test on the starting system to eliminate bad grounds

[hanz63]

I wasn't aware that they had an actual ACR other than the cam lobe design. The singles had some early failures. Bucket is a great word for those! Here's a clip from Kohler on the starters. It seems that the number of starters that the shaft actually break off dwindle every year.

A new inertia drive starter has been developed with many advantages over the previous design.
Improvements include:

Stronger shaft - shaft diameter was increased from 12.5mm to 17mm
Less susceptible to bending or fracture
9 tooth pinion down from 10
Ratio allows for increased torque
Patent RDD (rubber disc drive) encapsulates the rubber and shields the friction surface from contaminants
Solves the grease/oil contamination slip issue
Higher torque and speed
Higher speed translates to more frequent pinion and ring gear meshing, Cranking speed is 80 rpm faster than the previous motor
Better performance
Better roll over engine speed and no hot restart stalling
Stable cranking
No kick outs of pinion due to higher torque
Lower current
Shorter motor
Pinion cold forged

[StarTech]

The Courage Twin is not a bucket engine design. The bucket design is the single cylinder. Most Courage twins don't have a mechancial ACR through a few do. This Cub Cadet engine doesn't, may still be using a ramp or bump type system. I am fairly confident that your are cranking against full compression. Also this engine is a single camshaft design and not the twin cam design use on the singles.

Considering the hours it is likely the top starter bushing is shot and is causing binding. It doesn't take a lot either.

As for the valve adjustment just be aware the valve cover M6 screws tend to seize and would need to drilled out and resize if they break off. Use M7-100 as replacements.

[bgsengine]

:roll:
The Courage Twin is not a bucket engine design. s.

my bad, didn't notice the "twin" part (or look at the model).. just saw "courage" and immediately translated to "made in china junk" TBH I am less that impressed with Kohler engines any more.. but then not so impressed with briggs either - everybody's trying to cut corners and build cheaper to keep costs down, can't blame them, but still....

[StarTech]

...We still got to try to fix the junk. I agree things are going South on oil covered slope that they even add water to.

I was looking at Stihl MS170 that claims to have a 16" bar when I measure it, it is only 15". Yet another con by OEMs like when they claim a pressure has a 2700 psi 2.4 GPM when it clearly has 2400 psi 2.2 GPM pump and then put on a 3 gpm tip.

[hanz63]

I've never had to split a Courage twin. No leaking sump gaskets. 2 head gaskets and some breather updating. The rest is normal carburetor, broken or weak starters, ignition work, fwk and PM. Maybe toss a regulator in there but I don't recall any chewed up stators either. The air filter is pretty small. I had a couple though that the cylinders were badly worn. That's the worst that I have seen. Not lots on the Confident either. Still happy with the direction the Intek twins took. Not so much on the singles.