Flail Mower Let's talk flail mowers

[Dan in MN]

Are your knives straight? You may have dethatching knives on it.

Standard angled side cutter pairs.

This afternoon I changed the points, condenser, cap, and rotor and no improvement. Had to buy a timing light since I have no idea where mine went...probably threw it out a few years ago since I hadn't needed one for ~20 years... Was hoping the other stuff would be the solution so I could return the light, but no such luck. Getting the total timing set made a big difference in power, but as soon as the mower loaded up the roller again it just brought the tractor to it's knees...as soon as it bogged down completely this time I shut the pto off and drove back to the garage..

Roller full of grass..

All of this came off the roller!

Underneath full of loose grass..

Cleaned out..

I took the scraper bar off for now, but I'm pretty sure that's just going to allow the roller to really build up the grass. Up till now though, the grass would build up enough between the roller and scraper to jam the roller and I think it was probably just dragging and not rolling. I also always have heavy grass wrapped around the ends with the bearings (especially the right side), to the point where the bearing gets hot from being packed tight in insulation and also friction.

The grass was a little damp tonight, do others have trouble mowing if it's wet/damp or does it usually not matter? Wishing I had just bought a Bush Hog at this point...or no tractor at all...

 

[whirly]

Leave the scraper bar off.

If you are just mowing grass then it isn't really necessary.

 

[Alien]

From the look of that last photo it looks like it is throwing forwards. The front of the mower is dirty and the back is clean. This would make the tractor work really hard if the blades were turning that way.
If the cutters were turning the same way as your wheels the roller would not get covered like it does because the grass is driven down, not up over the top and on to the roller as in this case. It also makes it easier to propel the mower/tractor through the grass. The mower pushes rather than pulls against the tractor.
That's what it looks like to me anyway.

 

[Dan in MN]

According to the documentation that's the direction it's supposed to run, but I may look to see if the gearbox is reversible and try same as tires if possible..

 

[Xfaxman]

Looks like it is not spinning fast enough.

I wonder if your tachometer is accurate? There are mechanical and electronic devices to check PTO speed .

I would try increasing the RPM to max, while listening to the mower, if it is not vibrating or the sound of the rotor doesn't change much, lower the mower and see if it cuts like it should.

 

[Alien]

According to the documentation that's the direction it's supposed to run, but I may look to see if the gearbox is reversible and try same as tires if possible..

Worth a go. It's obviously not working as is.
Mine revolves the way yours is at present but I have the hammers on mine. It creates a vacuum cleaner noise when running and leaves nothing standing at all.
Underneath it looks identical to yours except for the blades.

 

[vlcakc]

Steave: "Is you 918 set up for rough cut and are you satisfied with it?"

So far as I have been able to determine, there is only one type of cutter available for the 918H. I asked about the availability of different cutters in an earlier post and got no response. Mine does finish and rough well so long as I keep the cutters sharpened. Vic

 

[kco]

According to the documentation that's the direction it's supposed to run, but I may look to see if the gearbox is reversible and try same as tires if possible..

That's the way my mower operates too, Dan. Sorry to hear the mower is not working for your conditions. I have limited experience but wonder if hammer-type blades would work better for the long grass. I have hammer blades on my AG180 (similar to ValueLeader AG180). They work great for brush and long grass. However, I have not done a lot of cutting in wet grass. My mower vendor recommends hammer blades over the grass blades and says all his customers prefer the hammer blades. Perhaps others with experience can comment on whether hammer blades might be more effective.

 

[IslandTractor]

Rotation of rotor, blade type, and scraper are all normal. Even if PTO speed is a bit low it shouldn't result in clogging the rear roller (I mow similar height and density grass with engine set 200-400rpm below PTO speed routinely).

I've never seen long grass clogging the rear roller before so can only speculate but 1) have you tried mowing more slowly and 2) is your tractor putting out enough HP to keep the rotor cutting? Does it bog down?

Do you have access to another tractor for a test comparison? If you mow in low range do you get the same result?

I have seen similar poor mowing with small clumps of un cut areas in a field before but that was always due to either several missing blades or wet grass or mowing too fast in thick dry grass. What I experienced wasn't as bad as what is shown in photos here though and in particular there was never grass wrapping around the rear roller. I've never seen grass wrapped around a rear roller before and think somehow that is the key clue.

 

[DieselBound]

I'm hung up on the first picture of the roller. Isn't that showing grass being slung over the TOP of the scraper? How can grass get slung in this way if the drum is turning in the same direction as the tractor's wheels? If the drum is turning counter to the tractor's wheels then I could the explanation being that the tractor is flattening some grass and the flail isn't picking it up well because it's rotating into the backside of the flattened grass, onto the top of the scraper.