Mowing Mowing with high speed pto

[Rod in Forfar]

When I bought my Bolens G174 the guy told me to run the Woods pto finish mower in pto speed #2, and 4th gear (1st high) at middle rpms. It works quite comfortably at that speed, but the Woods manual calls for me to run the mower at much higher revolutions, recommending 1000 rpm at the pto.

After eating two belts in two weeks I decided to try it more seriously. The thing winds up to a jetliner whine at 2700 and pto 3, though it cuts pretty well. The diesel engine has to work a lot harder, than in pto 2, occasionally letting out black smoke when under load. Everything gets hotter, though yesterday was a very hot day and I didn't see any evidence of overheating.

Mower cut is very good at both speeds. Is there any good reason to work the engine that much harder?

Thanks,

Rod in Forfar

 

[DonWorrell]

When I bought my Bolens G174 the guy told me to run the Woods pto finish mower in pto speed #2, and 4th gear (1st high) at middle rpms. It works quite comfortably at that speed, but the Woods manual calls for me to run the mower at much higher revolutions, recommending 1000 rpm at the pto.

After eating two belts in two weeks I decided to try it more seriously. The thing winds up to a jetliner whine at 2700 and pto 3, though it cuts pretty well. The diesel engine has to work a lot harder, than in pto 2, occasionally letting out black smoke when under load. Everything gets hotter, though yesterday was a very hot day and I didn't see any evidence of overheating.

Mower cut is very good at both speeds. Is there any good reason to work the engine that much harder?

Thanks,

Rod in Forfar

I may be wrong but I believe most finishing mower run a 540 pto speed. I have a Mahindra and my tractor says to run the finishing mower in low speed (540) and keep the RPM's at 2100.

Don

 

[DonWorrell]

According to the manual for a RDC54 finishing mower it should be ran in the 540 pto speed.

http://www.rivertrac.com/products2006/woodsfinish/heritage_mowers_lit.pdf
this website gives you all the specifications.

A RDC54 is designed to be ran with a 15 to 25 hp tractor.

Don

 

[Storm56]

If you have a 3 speed PTO like my 1502 does, I believe that the first speed is like 450, the second is like 700 or so, and the third is 1000 at PTO rated speed. I used to use a brush hog and just used it in the first gear at rated PTO speed and it worked OK. I would surely NOT use it at the third speed, and may try it in the second speed but at a lower RPM than rated.

I think the dealer gave you pretty good info.

 

[Rod in Forfar]

From a controlled test this afternoon I tend to agree that moderation is the rule, regardless of what the Woods manual says.

With the blades newly sharpened I started to cut a 1/2 acre grass parking area next to my shop. At middle to maximum revs in 4th gear and pto 2, the Woods RM48YM-2 cut pretty well, laying a steady flow of cut grass on the next row. The 17 hp diesel played with the mower in the 6" grass.

When I shifted to pto 3 it was a different situation altogether. The engine belched black smoke at startup and then found itself and wound its way around the patch. The cut was marginally better, but the clippings no longer made it out the chute: the blades left them mulched right in the mower's track. Over occasional heavy spots the diesel exhaust was easy to see.

Perhaps the requirement for a pto operating speed of 840-1000 rpm has to do with the mulching, rather than simply knocking the grass down. It certainly takes a lot more power to operate the mower at the higher speed. Things generally get a lot hotter around the tractor, as well, though again it showed no signs of overheating.

It's a 1987 mower and a 1981 tractor. Both seem to be in fine condition. I don't think my little trees will care if the grass next to them is not mulched. I'll stick with pto 2 and keep the knives touched up.

BTW: the mower runs a lot better with the 5/8" OEM belt. It rattled a lot with the 1/2" version.

Thanks for your input,

Rod

 

[Rod in Forfar]

According to the manual for a RDC54 finishing mower it should be ran in the 540 pto speed.

http://www.rivertrac.com/products2006/woodsfinish/heritage_mowers_lit.pdf
this website gives you all the specifications.

A RDC54 is designed to be ran with a 15 to 25 hp tractor.

Don

Don:

Thanks for the link.

This new mower uses a gearbox like a rotary mower. From the specs it provides the same blade tip speed as my ancient one, in the order of 16000 fps, with the 540 input.

With a big fan belt driven directly by the pto shaft, my '87 version needs a faster input to achieve the same optimum blade speed. Nonetheless, I think I'll run it more slowly unless I want to make the lawns really pretty for a special event.

Rod

 

[Kays Supply]

Be sure and monitor the gear box. I have tried a finish mower in the higher gears and the gear box got pretty hot. I put some additive in the box like Lucas and tried it again and it didn't get as hot, but I still went back to 1st gear.

 

[lens12]

Woods did make a series of 1000 rpm finish mowers for compact tractors when they first came out. They discontinued them several yaers ago. I know becuase, I purchased several when they had a liquidation sale of discontinued equipment 10 years ago.

 

[RightWay]

Interesting enough I found an old finish mower that is made like the Woods that the blades are belt driven directly off of a large belt pulley that is driven by the drive shaft off of the PTO. It's an old 1978 Bush Hog brand. I cant find anyone that has one or had one in the past. I pull it behind a Ford 8n and it does fine, but I pull it in 1st gear. I believe the ford has a PTO rpm of 545 @ 1500 RPM or so. That gives it a very high speed with the pulley ratio they used. It is a left side discharge. I dont have to worry about gear boxes overheating either. This mower is very similiar to the Woods model RM 59 because it uses all belt drive. There are two belts. One is 105" and the other is a 124" the same as the Woods uses.