It's a 2,000 rpm PTO, most tractors now use the 540 PTO. I'd doubt MF or Snapper would have any parts for you but I'd also bet there's someone out there that has that shaft. I've got several implements that run off of the rear PTO on my 1650 & 1855, thankfully all the shafts are good on them. Someone on this forum will know where to get those shafts, good luck.
There is no gear box. It's a belt drive in a very limited space. A reduction at the other end (engine) is not an option, direct drive and zero room.
There is already a 44% RPM reduction at the rear of that tractor. Achieving another 73% reduction will be a real problem. It will be easier to do it on the implement, get an implement with a 2000 RPM input, or go the hydraulic pump/motor route.
The last method is costly, but it creates a lot of different options for all sorts of implements.
To do it on the implement woud require a bunch of parts, and you still need the shaft.
I've thought a little about this problem over the last 28 years with my 1655, and I like the last idea the best. I just can't justify it with only a tiller requiring the pto, since I have the shaft for it.
Try a local industrial supply house, machine shop, or hydraulics shop for your splined shaft.
Thats what I ment is to change the implement. Trust Me it took 3 years to find the rear pto drive for this unit & I'm not about to change anything! I have to fit the motor yet. I have a kohler command 25hp I'd like to fit in for more power. I just won't be able to have a front electric pto. I wish I could find a onan 18 complete for it.
Onan engines are in lots of different brands and range from 16-20 hp that will work with the original electric PTO. The newer P2xx series is also a drop in with only minor wiring changes and a frame notch on the left side. I put a new P220 (20 hp) in mine several years ago, but it was pricey.
The implements usually come with their own PTO shaft, but if they don't, the shafting and universals are available at TSC. Only the splined shaft that fits the rear PTO needs to be sourced elsewhere. You might be able to get one (or 2 or 3) made at a machine shop for a reasonable price.
I stopped in at the local Parker Hannefin store late Monday afternoon to enquire about 1" x 15 tooth splined shaft for your MF1650. The second gent I spoke to didn't think he could get it here Tuesday because it was so late, but he could have it here Wednesday. I didn't ask the price since I was only checking availability. I told him I was checking for a friend in Ohio and asked where it could be ordered from.
On my Massey, I got a piece of shaft off another brand mower, then cut it to right length & ground a groove so it goes into the rear PTO of the tractor, with a second groove on the exposed part for a std female implement shaft to attach to . Now it looks like a large tractor with the PTO shaft sticking out instead of a female PTO. The slip on PTO shafts are easy to get hold of. If I need, I can simply pull out this stub shaft to use the original style implement shaft. I'll try to get a pic of it tomorrow & post.
MF offered as an option for the 1655/1855 tractors, a 540 rpm PTO kit to put on the tractor. I'd forgotton that JD used that same shaft, as much as I love my red tractors you've got to hand it to JD for parts availablity. I looked in my 1655/1855 MF partsbook at that 540 conversion kit, mainly two big double row sprockets mounted on shafts with a idler/tensioner sprocket. By pulling four hairpins clips you can slide it off of the tractor, looks to be an easy on-easy off deal. Darn, Olcowhand, now you've given me another project for my tractors. They would look better with the 540 shaft sticking out.
Here are pics of what I did. Implement shafts commonly have female quick connects, so I opted to make my rear PTO a male output. I bought a front PTO shaft from an Ariens GT, then cut to length, then ground grooves for lock positions. The groove closest to my thumb is what I started with to lock into the tractor's PTO, but extended the shaft out a bit too far, so I ground the 2nd groove from my thumb for the one I use. This kept the shaft shorter, plus puts the implement's quick connect right up against the tractor's PTO to where I slide shaft up all the way & it's dead-on the locking groove.