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7/6/2025
Angeou
2019/01/12 10:01:24
john.page3

Gravely 2012 ZT48HD,

I want to convert the Vertical shaft engine to a Gear Box and a Horizontal engine.
For some reason most vertical engines do not last as long as horizontal engines.
I was thinking to add a Bushhog gear box and change out the the engine to a heavier horizontal commercial grade engine.
I know this will take some welding modifications.
What I'm looking for is, what RPM's does the hydraulic pump need be running at to operate that system?
5 comments Leave a comment
AVB
Better off just installing a commercial grade vertical engine.
 
Since this unit appears to have twin Hydro Gear hydrostatic transaxles. The input speeds for these are 1800 RPM min and 3600 rpm max.
 
You also be needing to convert the drive drive too. Most ZTRs that run horizontal engine uses wheel motors and one or two hydro pumps. Plus to drive the deck to additional pulley to convert from horizontal engine output back to vertical. You take a look as some JD ZTRs to get an idea how they did it.
2019/01/12 10:35:01
john.page3
Ok, you answered my question. thank you.
Ok, so if I go back to a Vertical engine, is a B&S as good as the Kawasaki.
I'm looking at a  Briggs & Stratton 25 HP 724cc Commercial Turf Engine 1 x 3-5/32 #44T977-0015.
Everything looks like it will match up. Other than I think it has an automatic choke?  
2019/01/12 11:04:06
Roy
By the time you finish cobbling your Gravely you will have been better off selling it and purchasing a machine equipped the way you want. Vertical shaft engines last as long as their horizontal counterparts as long as they are properly maintained. Kawasaki is good (and expensive) but I'm not convinced it is any better than the Briggs commercial or Vanguard for a rider application.
2019/01/12 12:03:13
B53
john.page3
Ok, you answered my question. thank you.
Ok, so if I go back to a Vertical engine, is a B&S as good as the Kawasaki.
I'm looking at a  Briggs & Stratton 25 HP 724cc Commercial Turf Engine 1 x 3-5/32 #44T977-0015.
Everything looks like it will match up. Other than I think it has an automatic choke?  


The Vertical engine oil system is NOT designed to be used a a horizontal engine. Think about it..
 
If swapping engine brands make sure the output shaft is correct size & length. 
2019/01/12 21:25:08
AVB
HP rating are gross HP at 3600 RPMs.
 
Most likely with Kawasaki being labeled 25HP it is the FR730. That is governed at 3500 RPM max. The Briggs 44T977-0015 was governed at 3300 RPM max so you will lose some speed in both motion and deck operations but it no longer in production and is replaced by the 44T977-0009-G1. A better option would be the Briggs Vanguard 49R977-0008-G1 rated at 26 hp. Cost more than the smaller Briggs but has a better warranty is more suited for the application.
 
 
2019/01/13 00:26:23

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