Proud new owner..................422 arrived today

MossRoad · Jun 5, 2004

I think when they say don't give it full throttle on a hill they mean full treadle. I would think you would want full trottle so that you would have the maximum PSI available to push the juice.

Remember, if you want more power to the wheels, let up on the treadle. Stomping the treadle down when you need more power(not speed) will bog the engine.

toy · Jun 6, 2004

Running the engine full throtle turns the hydraulic pumps faster and in a strain will give you more available power to the wheel units and to the power takeoff. It is my understanding that the hydraulics is an open center system which means that unless you activate the power takeoff valve the pump pumps in an unrestricted circuit and dumps back into the tank. When you activate the power take off you close that open center and force the hydraulic fluid to go to the implement turn the implement and then back to the tank. Now the wheel units is on a different circuit, it is on the variable volume pump . The hydraulic oil that goes to the treadle when the treadle is pushed sends oil to the variable volum pump which shifts a plate in the variable volum pump. The more that plate is shifted the more hydraulic oil the variable volum pump puts out as the plate spins, at least that is how it works on larger variable volum pumps that i have seen . Since the mower is on one circuit and the wheel units is on a seperate circuit as AI described The blades turn at a constant speed according to how much oil flow is available from the pump but the speed of the tram is not so you can drive very slowly or at full treadle and that doesn't effect the speed of the blades. Mowing tall grass will effect the speed of the blades . Running at full throttle [engine] will give you more volum of oil to meet the needs of the job that you ask it to do. I have found that when the engine is bogging down if I pat the treadle it will help overcome the strain without killing the engine. Sorry if this post is too lengthy.

toy · Jun 6, 2004

I operate mine in a similar set of circumstanse and I have to keep both my feet on the treadle for a quick reverse if needed. Like was stated earlier I use blocks cut to the shape of the floor but not extending sallthe way to the treadle and with screws in the blocks to stick into the clean out hole to keep the blocks from sliding forward. With these two 2by six blocks my heals rest fully on the blocks and withan easy treadle I use my ankles to give it tram less strain on my legs ankles and back. The blocks come out easy to clean out the floor. I first came up with this as a temperary solution but it worked so well and after all the blocks was pressure treated that I decided to use them until they rot out, when they do I might just replace them with two new blocks.

toy · Jun 6, 2004

I have found that when I hear the engine bogging down if I pat the treadle that it helps keep the engine speed up and helps to over come the strain of the climb.

FOURTEEN · Jun 6, 2004

"" I think I'll give it a try ""

Good for you!! I'm sure you will like it!!

It is a quick and inexpensive modification. Installing the rubber treadle dampers does not change the OEM setup in any way. You can revert to OEM by just fliping the loops off the ends of the pedals.

Everyone who has tried my PT both ways has remarked that it is so much easier to control with the rubber treadle dampers installed!

I often use both feet when using the Stump Grinder, MiniHoe, Grapple Bucket, or Potato Digger, or when grading and compacting soil. The only difference is that the pedals are less sensitive, and are less prone to react inappropriately on rough ground. When going in one direction you don't need your foot on the other pedal to provide back pressure. You know when you are pushing on a pedal, or just moving your foot around! It's very obvious where "neutral" is!!

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Clarke · Jun 6, 2004

I have the 60" deck and in that area it is uneven in spots. Sometimes I will hit one of these and stall a mower blade. If you don't back up or go forward or something the engine may stall.

sg

MuncyBob · Jun 6, 2004

Well...I'm learning something new every day...after my limited time on the PT I sorta was thinking along these lines but not so detailed(I really don't know much about hydrualics..but I'm learning!)...now, if it will just dry up a little today I can add to my 2 hours of experience LOL! /forums/images/graemlins/laugh.gif

SnowRidge · Jun 6, 2004

We operate the machine at full throttle (called high idle by Kohler /forums/images/graemlins/confused.gif). We have never stalled the engine, even when we have bogged the mower, which we sometimes do if we go too fast when we mow really tall, wet grass around our Xmas trees.

As far as I know, these machines should always be operated at full throttle. The only time I don't do it is if I am moving the machine in very close quarters, such as inside the shop where there is a danger of hitting something. Then I run about half throttle to minimize pedal responsiveness, and also to lessen the amount of damage I might do in case of a whoops. The PTO is never on in such a case.

I would suspect the Robin engine manual that says that full throttle may lead to a stall is talking about something other than hydraulic drive. With a manual transmission, the statement sounds right to me, but not with a PT.

SnowRidge

pah · Jun 6, 2004

this is an interesting question about operating at full rpm or not. the robin manual states "whenever high speed operation is not required slow the engine down ... to save fuel and extend engine life. I tend to operate my machine at lower rpms except where max power is required. Any other opinion's or reasons for doing so or not?