Belly mower does a ragged job - why?

[ruffdog]

Wow....500 less engine RPM than what it was designed for is a huge drop in mower blade tip speed.

 

[nyone]

Wow....500 less engine RPM than what it was designed for is a huge drop in mower blade tip speed.

Since the belly pto operates over 2000rpm a 500rpm drop could mean 1000rpm less blade tip speed.

 

[4570Man]

I can visualize putting the mower blades on upside down by mistake, but how do you put one on backwards?

Wouldn't it either be "right side up", or "upside down"?

You can’t put them on backwards unless you bought pretty rare left hand turn blades and put them on a right hand mower.

 

[sunandsand]

OK, took the belly mower off the tractor, put a couple of chains on it and lifted it vertical so I could get at it using the FEL. (Safety blocked as well, it weighs 300 lbs.)

No crud accumulated under the deck.

Belt appears OK, not glazed or cracked.

Blades installed by dealer or factory so they are right side up, but see below. (Note that dealer setup was "indifferent", I've had to correct a few things here and there. That's what I get for reading instructions and manuals.)

Blades not bent, but VERY, VERY dull, these desperately need to be sharpened.

There's a flat metal plate bolted to the leading edge of the deck, one on the left side, there are holes in the deck for one on the right (discharge side). The left one is present, the right one appears to never have been installed. The plates extend back horizontally from the lip on the deck back perhaps an inch on the left side, no idea on the right side because it just isn't there and I've never seen it.

No marks showing if it was torn off or fell off, paint is undisturbed. I *know* if it came off while I was mowing, it would have made a heck of a racket, in fact, the equivalent plate on my riding mower HAS come off (twice, vibrated apart) and stopped the mower dead each time.


So here's the plan:

1) sharpen and balance the blades

2) determine if the baffle plate is missing, if so, buy and replace (with hardware, three carriage bolts and nuts)

3) clean everything, inspect everything, lube everything. Easy when it is off the tractor, not so easy when it is on.

3) run at higher tach speeds, probably 2,300 or so. (I have to adjust the throttle friction washer, the RPM likes to slowly drop to about 2,000 to 2,100 RPM if I don't hold the throttle open.)


This will probably happen this coming week, so stay tuned!

Best Regards,

Mike/Florida

 

[4570Man]

Your blades probably need chunked and get new ones if they’ve been ran 70 hours without maintenance especially in Florida.

 

[sunandsand]

I'll let the sharpener guy look at them in the next day or so. If I need new blades, I'll get them. No biggie.

I did look at the parts book for the RCK54 mower - there doesn't appear to be the right side guide plate/baffle plate as on the left side. I'll check with the dealer Tuesday.

Best Regards,

Mike/Florida

 

[Have tractor did travel]

Every mower I've ever had except for REAR PTO driven mowers has been run at WIDE OPEN THROTTLE.

Push mowers, cheap riding mowers, tractors with belly mowers -- always run wide open.

Does anyone have a push mower that they don't run at WOT? Why would a belly mower be any different?

My RC72-27B (72") mower cuts really slick running at WOT. It would do a lousy / ragged job at 2100 RPMs.

Deere makes marine diesel engines (stay with me folks, you'll see the tie in to tractors). They rate those engines in 5 gradients, using a rating system of M1 to M5:"

M Rating	Typical Load Factor	Typical Annual Useage	Typical Full Power Operation
M5	≤ 35%	≤ 300 hr	0.5 of each 8 hr
M4	≤ 40%	≤ 800 hr	1 of each 12 hr
M3	≤ 50%	≤ 2000 hr	4 of each 12 hr
M2	≤ 65%	≤ 3000 hr	16 of each 24 hr
M1	> 65%	> 3000	Uninterrupted

In this system, M5 points to engines for recreational cruising boats. The manufacturer is telling us that the M5-rated engines will maximize longevity when those three parameters are met."
Absent particulars from the tractor engine manufacturer, I'd be hesitant to subject my CUT, or SCUT to "full power operation" any more than 25% of the time.

 

[4570Man]

Deere makes marine diesel engines (stay with me folks, you'll see the tie in to tractors). They rate those engines in 5 gradients, using a rating system of M1 to M5:"

M Rating	Typical Load Factor	Typical Annual Useage	Typical Full Power Operation
M5	≤ 35%	≤ 300 hr	0.5 of each 8 hr
M4	≤ 40%	≤ 800 hr	1 of each 12 hr
M3	≤ 50%	≤ 2000 hr	4 of each 12 hr
M2	≤ 65%	≤ 3000 hr	16 of each 24 hr
M1	> 65%	> 3000	Uninterrupted

In this system, M5 points to engines for recreational cruising boats. The manufacturer is telling us that the M5-rated engines will maximize longevity when those three parameters are met."
Absent particulars from the tractor engine manufacturer, I'd be hesitant to subject my CUT, or SCUT to "full power operation" any more than 25% of the time.

WOT and maximum power aren’t the same thing.

 

[Have tractor did travel]

WOT and maximum power aren’t the same thing.

Agreed. But . . . How do you get more power if you're running at WOT ?

 

[Gee Ray]

The sand in Florida is hard on the blades so sharpening them often is a requirement. Also look at the upturned back edge if they are on your blades. This upturned edge will wear quickly and this wear will cause a poor cut. Slow the ground speed of your tractor and as the others have said increase the engine speed.

If you are accustom to a gas engine mower forget the sound worries and run wide open. That is best for your diesel. It does not save much fuel to slow the diesel down and then load it up cutting grass.

You should not be trying to mow with the tractor set in the high range. M should be OK for mowing but L may be needed for heavy mowing.