NH 451 mower

[L Hud]

i am new to a 451 with double guards. The hay does not shed off the guard as well as a regular guard. The short cuttings get caught in the guard. Is there a trick to keep this from happening. Thanks in advance. LH

 

[Baseball Fan]

Does adjusting the mower so the guards tilt slightly upward help? The knife, hold downs and wear plates are all in good shape, correct? I really like my 451 but it's used more for trimming instead of hay.

 

[L Hud]

i use mine for trimming and pasture clipping. everything is in good shape an serviceable. First time dealing with double guards. I have used 501s for years.

 

[Destroked 450]

Double guards are great, that’s all I ever used on mine
There is a number of adjustments that need to be correct to get the mower operating at its best
Yoke needs to be set to hold the mower frame at around 15-16” off the ground and level
Skids need to be set to hold to knives 3” minimum from the ground, for pasture clipping I set them to mow a least 4” minimum
The bar need to be tilted back some so that the tip of the sections are slightly higher than the back, don’t have my manual here to give exact numbers. The end of the bar should also have a few inches of lead when pulled back in working position
When mowing short grass mine would build up a little at the back of the guards but never enough to cause a plunging issue
The main drive pulley is also adjustable to correct the mower’s operating speed depending on the tractors pto speed
Mine was set correct but FIL’s wasn’t and had the mower running at a slower speed, I reset the shims in the pulley and it mowed much better and faster

 

[E.B. Haymakin']

Double guards are great, that’s all I ever used on mine
There is a number of adjustments that need to be correct to get the mower operating at its best
Yoke needs to be set to hold the mower frame at around 15-16” off the ground and level
Skids need to be set to hold to knives 3” minimum from the ground, for pasture clipping I set them to mow a least 4” minimum
The bar need to be tilted back some so that the tip of the sections are slightly higher than the back, don’t have my manual here to give exact numbers. The end of the bar should also have a few inches of lead when pulled back in working position
When mowing short grass mine would build up a little at the back of the guards but never enough to cause a plunging issue
The main drive pulley is also adjustable to correct the mower’s operating speed depending on the tractors pto speed
Mine was set correct but FIL’s wasn’t and had the mower running at a slower speed, I reset the shims in the pulley and it mowed much better and faster

If you don't have a manual I post some images. I was experiencing serious plugging issues up this spring. Turned out the drive belt was loose in my description. Followed the manuals instructions and tightened the belt by loosening then adjusting the PTO/pulley assembly and no more plugging

 

[E.B. Haymakin']

i am new to a 451 with double guards. The hay does not shed off the guard as well as a regular guard. The short cuttings get caught in the guard. Is there a trick to keep this from happening. Thanks in advance. LH

 

[E.B. Haymakin']

i am new to a 451 with double guards. The hay does not shed off the guard as well as a regular guard. The short cuttings get caught in the guard. Is there a trick to keep this from happening. Thanks in advance. LH

 

[L Hud]

A friend has a 451 with regular guards on it. He does not have the build up problem on his guards. I think maybe it is the sharp surfaces doing a better job of cutting the material. Thanks guys for all the info.