Scag Turf Tiger/Kohler Command Pro 27 Frustrations

arussel88

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
2009 Scag Turf Tiger
27hp Kohler Command Pro (I don’t know the model number as the sticker has long since disappeared)
650 hours (653 hours now, bought used 22June2018)

Starts strong, runs great for about 30-40 minutes then begins to lose power while blades are engaged. I can release the blades and let the sucker stand for a few seconds and the engine begins to sound “right” again. Then…once I start mowing again…same thing, engine loses steam. I can let is sit for 30-40 minutes and go through the whole routine of mowing for 30-40 minutes with no problem before the issues start again. There also seems to be an oil leak near the dipstick.

Here’s what I have done:
Compression check: 120psi on both cylinders. I’ve heard this number doesn’t mean much for these engines because they have a built-in release valve.
Replaced spark plugs.
Drained all the previous owners gas and replaced with “clean” gas.
Checked for spark with inline tester both resting, under load, and when it is acting up. Clean spark. At least that what the tester tells me.

Could it be:
Ignition coil? I know there will be a consensus that the DSAI thing is junk and my problem. My ignition coil number is 24-584-36. The kit that is supposed to “fix” this direct ignition problem does not show compatibility with my model coil number.
Worn/sticking valves? If so, can this be rebuilt with long term success or will the problem eventually resurface?
Carburetor?
Tiny rip in the seat?
Yes, I know I have posted this on other forums.

Thanks, all!
 

ILENGINE

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
No compression release used on command twin engines. Service manual list minimum compression to be at least 160 psi with no more than 15 percent difference between cylinders. Your module doesn't have an upgrade conversion since at the time of manufacture that was the upgraded system, but proper checking of the ignition modules requires the use of a HEI (high energy ignition tester) because a normal inline tester can show a faulty module as good.

I suspect that you have a bad module. When the engine is acting up try grounding the plugs one a a time and if you are dropping a cylinder the engine will die when you ground the good cylinder.
 

cpurvis

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
This is a long shot, but have you checked that the cylinder cooling fins are free of debris?
 

arussel88

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
No compression release used on command twin engines. Service manual list minimum compression to be at least 160 psi with no more than 15 percent difference between cylinders. Your module doesn't have an upgrade conversion since at the time of manufacture that was the upgraded system, but proper checking of the ignition modules requires the use of a HEI (high energy ignition tester) because a normal inline tester can show a faulty module as good.

I suspect that you have a bad module. When the engine is acting up try grounding the plugs one a a time and if you are dropping a cylinder the engine will die when you ground the good cylinder.

Thanks. Ok, just to confirm I will only be able to buy the same module as the two currently on my ride not one of the conversion modules? And by module you mean ignition coil module or is this something separate like that little black box near the engine?

Also, do you think it could be vapor lock or the something with the muffler? I tried all the gas cap tricks and such.
 

arussel88

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
Original poster here....

It looks like I have the SAM module. Part # 24-584-31. Does this mean I need to purchase new coils and a new module or do these conversions eliminate the SAM?
 

ILENGINE

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
Original poster here....

It looks like I have the SAM module. Part # 24-584-31. Does this mean I need to purchase new coils and a new module or do these conversions eliminate the SAM?


The 24 584 31-s SAM used with the 24 584 36-s ignition modules get converted to the new MDI system with kit number 25 707 03-S. Remove and throw away both modules, and the SAM. The kit contains both new modules and the wiring parts to convert to the new system complete with instructions. The kit is just a little under a $100.
 

bertsmobile1

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
And taking a different tack.
Get yourself another fuel tank, pinch it off your push mower if you like, it does not need to be a big one.
put some fuel line & a tap on it.
When the mower starts to play up quickly plug in the new tank at the fuel pump inlet , you will need a plug for the old fuel line and a golf T will work really well for this.
If the mower runs fine on the new tank then you have a fuel supply problem generally debris in the tank.
 

arussel88

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
I pinpointed the oil leak. It's coming from that little screw-a-magid on the breather cover, I can safely assume the gasket is blown? Just below the carburetor. I have seen some posts where this cover design was discontinued due to hose issues but my hose is fine. (Pause for chuckle) Most folks are saying the cracked hose caused some serious carb damage which in turn caused some serious engine damage. Would the worn gasket have the same effect as a cracked hose? If so, how could this ruin the engine? The small "filter" under the breather cover was barely noticeable. Also, cleaned the carb really well. No noticeable signs of malfunction not even much gunk.

Probably going to buy the ignition coils and replace breather cover gasket then sell the dern thing.

If I decided not to sell...A rebuild kit goes for 250. I have a fella who will install for 250. Promises (160psi) after he's done with it. Let's say it's not the coils or carburetor and it's just worn/sticky valves. Can this be "fixed?" Guy at ExMark dealer told me the damage is done and the valves cant be fixed by putting a new set of rings etc on it.
 

cpurvis

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  • / Scag Turf Tiger/Kohler Command Pro 27 Frustrations
The Guy at ExMark Dealer is either crooked as a dog's hind leg or dumber than an ox.

I suspect the former.
 
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