# Troubleshooting King Kutter Finish Mower



## yooper56 (6 mo ago)

Last time I used my KK 6 foot finish mower it suddenly stopped cutting. The blades would work intermittently. I shut it down and started to check obvious things. I changed the belt, which had some pieces missing and lots of cracks. Not sure I got the tension right when I reinstalled it, and not sure how to know what the right tension is. I greased everything I could find fittings for and that was really overdue, so something else might be damaged from lack of routine maintenance. The gearbox oil level is good. When I changed the blades, there was no evidence of grease at the bottom of the center spindle. The other two had traces of grease. When I manually move the belt, the blades turn but when I engage the PTO, the mower deck doesn't cut. Suggestions on where I go from here, please. The deck is attached to a John Deere 790.


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## bmaverick (Feb 20, 2014)

yooper56 said:


> Last time I used my KK 6 foot finish mower it suddenly stopped cutting. The blades would work intermittently. I shut it down and started to check obvious things. I changed the belt, which had some pieces missing and lots of cracks. Not sure I got the tension right when I reinstalled it, and not sure how to know what the right tension is. I greased everything I could find fittings for and that was really overdue, so something else might be damaged from lack of routine maintenance. The gearbox oil level is good. When I changed the blades, there was no evidence of grease at the bottom of the center spindle. The other two had traces of grease. When I manually move the belt, the blades turn but when I engage the PTO, the mower deck doesn't cut. Suggestions on where I go from here, please. The deck is attached to a John Deere 790.


Nice, a Yanmar in JD green paint.

I have the brush mower version. Is there a belt tensioner to adjust with? On my old JD261, it was a spring the size that fit on a trampoline. In fact, when that spring corroded away, I used one as a replacement.  Worked perfectly.

Do you have the PDF manual for it? Does it show just pulleys with bearings or does it have spindles that have straight splines on the shafts? The spindles tend to strip the splines and need replacing. 

Those would be my go-to for now since other things were looked over.


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## BigT (Sep 15, 2014)

It might be your tractor's PTO clutch slipping??


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## yooper56 (6 mo ago)

BigT said:


> It might be your tractor's PTO clutch slipping??
> I have better tech manuals for the tractor so I'll look at that. The manual I downloaded for the mower deck was good for the diagram on the belt installation, but pretty thin otherwise.


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## yooper56 (6 mo ago)

bmaverick said:


> Nice, a Yanmar in JD green paint.
> 
> I have the brush mower version. Is there a belt tensioner to adjust with? On my old JD261, it was a spring the size that fit on a trampoline. In fact, when that spring corroded away, I used one as a replacement.  Worked perfectly.
> 
> ...


I downloaded the manual, and there's a tensioning pulley with a spring, also an L bracket set up that will loosen or tighten the belt. There's just no info anywhere on what's the right level of tension. The deck has three spindles. Don't want to open those up unless someone can tell me that they are likely the problem. Since it was working intermittently I'm thinking it's something else.


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## bmaverick (Feb 20, 2014)

yooper56 said:


> I downloaded the manual, and there's a tensioning pulley with a spring, also an L bracket set up that will loosen or tighten the belt. There's just no info anywhere on what's the right level of tension. The deck has three spindles. Don't want to open those up unless someone can tell me that they are likely the problem. Since it was working intermittently I'm thinking it's something else.


With belt tension, the rule of thumb is having the slop at 1 index finger. 

Tighten belt to the level of no slop first. DO NOT OVER TIGHTEN.
then back off for 1 index finger of slop. This is normally the tension needed with a spring setup. 

Overtime you will need to re-check the tension as belts stretch from usage. 

For mower decks of long belts, I found the Kevlar enforced belts to work the best with little to no stretch over time. They hold up really well should they bind up in the machine. Just take off, and re-apply. V-Belt Supply is the best costs I've found on the web for the Kevlar belts.


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