Powering riding mower

[katoomed00]

IMO 5.5hp would be pretty gutless through a hydro transmission in a tractor that heavy unless your land is completely flat and you plan on towing feathers. Your call though.

Agree, I took a 6.5 hp HF horizontal shaft engine, to make a small low volume power pack for my bucket lift. I ended up having to put a 2" pulley on the motor and 11" pulley on the pump just to get 1100 psi output. Anything smaller on the pump would stall the engine. Also set the relief valve @ 1000psi just to make sure not to stall the engine while I was in the air, also had an escape ladder and cell phone incase it did, LOL

 

[GLyford]

Some of the newer push mowers with the blade clutch will run the same but a lot of the older push mowers wouldn't run worth crap without the blade or some type of extra fly wheel weight. And no the just put heavier flywheels on the same motor for other duties.

I would agree with this ^^^
And would note that when shopping for an engine that I often see some with heavy fly wheels listed. Some motors with light fly wheels depend on the mass of the mower blade to run smoothly and that has been true for the last 50 years or so that I know of.

Exactly. Run the calculations on rotational inertia on a 2" wide 1/4" thick piece of steel that sticks out 10" on either side of the axis, then figure out what you'd have to replace that with in a smaller flywheel arrangement to match it. Last time I ran the calcs I ended up with a 25 lb. weight from a weight set, and it was still rough as heck (hard to balance) and hard to start (not enough inertia). Plain push mower engines have a cast aluminum or zinc flywheel. The heavy ones like in pressure washers are often cast iron. Look up the engine codes, they will tell you which flywheel the basic block (which can be used for either) was built with.

It's easiest to avoid push mower engines completely, especially if they have the engine brake.

My little buggy above was made for carting mulch around, which it does OK. I think that's a 6hp, I'd have to go look to be sure, and it runs a gear transaxle. Because the rider's weight is no longer over the front wheels, the chassis is also full of bricks (really only needed when empty).

It's gutless with dirt in it, so if you are looking to move more weight around or support the power losses of hydrostatic you'd want to upsize to the next size block, the 8hp or so from a rear engine rider. I was looking for fuel economy and something that would run on a pull start with no battery to maintain for as little as it gets used. For my needs, the little 6 does OK. Some of those 8-10hp rear engine mowers came with a pull start too, if that idea appeals to you...and the bolt pattern and output shaft will usually match what you already have.

 

[4570Man]

Agree, I took a 6.5 hp HF horizontal shaft engine, to make a small low volume power pack for my bucket lift. I ended up having to put a 2" pulley on the motor and 11" pulley on the pump just to get 1100 psi output. Anything smaller on the pump would stall the engine. Also set the relief valve @ 1000psi just to make sure not to stall the engine while I was in the air, also had an escape ladder and cell phone incase it did, LOL

I wonder what kind of gpm and pressure a lawnmower HST transmission has. I know 2200 psi is the best I can do with a 5.5 hp Honda on a 11gpm 2 stage pump. It's 2 gpm on the high pressure side.

 

[texasranger556]

A tractor like the OPs would be in the neighborhood of 15 GPM at full stroke, not sure what the relief pressure is but somewhere between 2-3000 is likely. A service manual would have a test for it. Keep in mind that is a variable displacement piston pump versus a gerotor or gear pump. Piston pumps are more efficient but generally have a smaller charge pump optimized for driving a fixed displacement motor.

 

[jwmorris]

I didn't have the same issue as some when I have removed blades from vertical shaft engines.

They ran just fine with much less "fly wheel".