B7100 Upgrades / Mods

Just got a new to me B7100HST, it was in ok, to poor shape, but it's coming around soon enough.
It had the motor tore 1/2 way down when I got it and I took the chance that it might run, there was a thick coat of oil in the all the ports of the heads so I was hoping that it was a valve seal problem, I got a top end seal and gasket kit, I cleaned it all up and put it back together.
Well that was a lost gasket and seal set as the rings are bad and it has way too much blow by. After a long attempt I did get it to start and run but I think it had more flow out the vent pipe than the exhaust pipe.
Well after a lot of research I had a plan that I set in motion. Get a new D950 motor to replace the D750 But on a budget.
I was able to locate a low hour Jacobson Textron / Kubota 21.5HP D950 for $500. That turned out to be in excellent shape and runs perfectly, that's always a crap shoot when buying long distance (NY). and I was able to get it sent here for $175.
The differences between the D750 and the D950 are mostly minor besides the 16 to 21.5 HP improvement.
It has a water pump and a alternator both of which I wanted, it just required me to alter the radiator just slightly with a couple of copper fittings to get it to work right.
When I got it included a multi piece fan blade (broken) and I had to find a replacement I was only able to find a 5 blade fan that was too large off of a L series, but it was pitched the right way and had the same offset so I just cut the blades down.
I'm riding the fence right now on which alternator I want to use. I have a 125 amp alternator off of a Chevy that will work great, but it's pretty bulky. I will have to alter the hood just slightly on the left side to get it to fit but I can live with that. I will also need to make sure it will clear the loader that I'm building.
One major difference with the motors is the injector linkage, the original uses a solenoid to shut it down, easy fix just need to wire it in to the key. I kind of like it, it's an upgrade from the throttle lever kill.









I'm a little baffled by the front Rims. All the pictures of this tractor I've seen have 4 lug front rims and I have 6 Lug rims?


I will also be up sizing the wheels and rims on the front and rear to give it a better stability and width.

kubotasam, Big Kahuna, Thanks for the info!

BadDog, Your in my old stomping grounds, I lived in Phoenix for 21 years before moving up here, Couldn't take the heat any longer!
I looked at doing a rebuild on the D750 and the parts were more than I paid for the newer D950. Keep an eye on Craigs list and EBay they show up on there every now and then.

Rob, I didn't run into any issues with the pilot bearing fitting, I did have to get a new one for it as the Jacobson doesn't use a clutch set up, it's just a direct drive to the pump. I used the flywheel and clutch disk and pressure plate from the D750. I'm finding out that this is a newer model of the B7100 and it has a few things different then the older models.

I'm fitting the 125 amp GM alternator to it right now should have it done here shortly. That won't have any problems running the lights, and keeping it charged.

Still on the fence as if I should put a second pump on it to run the FEL or just tap into the hydraulic system that's already there?
I have all the parts to do a quick hook up. I'm thinking it will be a little more powerful and quicker, and it will eliminate any chance of hurting the drive on the tractor.

gssixgun, Yeppers it is! It's up and running and getting started on the loader here shortly.

seanbarr, I've rebuilt a few of those. If you can't find anyone to do it give a shout.

tmessenger, It's not pulling too hard... In fact I didn't even notice it, but I do suspect the battery is fully charged and the lights didn't pull it down too much.


I got the alternator brackets made, installed, and set up. I will still need to do a little more work on the side shield and the hood, but it will do for now. It's ended up being narrower than I first thought it would be, the loader will fit fine around it.




I also installed the LED head lights.


I picked up and old cement mixer and thought it would be nice not to have to lug it around by hand so now it's got a 3 point set up to move it around. I was thinking about making it PTO powered but this works for now.

Going like a mad man here the last few days building a loader for our B7100HST.
I looked at 100's of pictures on the internet , made a few sketches of what I wanted and dove in head first.
I wasn't really sure of the size of the steel to use so I went to the heavy side of it, 3/16". I read most use 1/8" and 1 1/2" cylinders or an upgrade with a 1 3/4" cylinders, I'm using 2" so I want to keep the strength.
Well take a look and tell me what you think.
These first 5 pic's are just tack welded together for fitting.

Second day's work... Can't wait till it gets all done so it can help me build a shop so I can quit working outside in the dirt.
Now that all the frame work is done and I've figured out the length of the cylinders I'll have to wait for them to show up to get more done.
I tried to find a bucket to no avail so I'll have to start making one of those too.
I'm also making a grapple bucket for this too so I can pick up brush with it.
I have the single handle loader control and will be using a push button 3rd control for the grapple.
If the weight of the loader and bucket make it hard to steer I'm thinking of going with a completely hydraulic steering unit, No more steering box or linkage. I have the unit here just hanging around not doing anything.
Here I've pulled the frame all off the tractor and welded all of it together with all of the supports and reinforcements, then reinstalled all of it.
I was worried that it wouldn't line up when it was all done, but it ended up being within a 1/8 of an inch so I'm happy with it.
When the cylinders get here I'll put the rest of the supports on the loader arms.

I'm getting ready to order all the Cylinders (2" double acting), Lines (3/8 steel), hoses, fittings, I already have the main spool valve but I'm ordering the electric valve for the grapple / third function, and yes I am going to fit it with a bobcat style and size quick connect.
I should have more pictures soon.