OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Walk Behind Lawn Mower Frames Reel Lawn Mowers, Atco & Villiers etc. Rover 45 new engine - which shaft size

I am about to pull the trigger and purchase a new Briggs and Stratton engine for my Rover 45.
The B and S 550 series 3.5HP is a direct swap (correct me please if i'm wrong)

My question is, which shaft size do i choose - 3/4 or 5/8
Given I am willing to recondition my clutch etc...my decision is guided by availability of clutch parts, as I believe the engine side clutch half is what comes in either size?
Looking around the internet the 5/8 clutch half seems to be a lot harder to obtain then the 3/4 version ?

any input in terms of size recommended is appreciated

Alex

Hi Alex,
Welcome here, BB will be along shortly to give you the advice you need

G'day Alex,

Welcome.

This is my take on it. When researching new engines for my little 14", unless I wanted a Chonda or similar, the only decent engine in 5/8th was a Honda GX100. I wanted to keep my original cast iron clutch, so that didn't leave a whole lot of choice!

The Briggs and larger GX motors were too big to fit nicely between my original straight bars without extension plates as well.

You can get Briggs in 5/8th, but not the GX series of Honda engines anymore. They're all 3/4 (19mm).

If you need a new or reconditioned clutch, go 3/4. If your flash new Briggs ever lets go you're "future proofed" and won't need to swap out a clutch again. That's my recommendation.

Since you're in Perth, check out Trident Lawnmowers in Swan View. They make new alloy and cast iron clutches, in both sizes.

Thanks for the reply Mystyler
Definitely leaning towards the 3/4 inch shaft in the b&s motor.
Will do some googling and see what trident mowers have to offer.
I’m gathering I won’t have the issue of extension plates and clearance between the bars as I have the larger 17 inch mower (rover 45)

Hi Alex

I am trying to remember what BB said a few months ago that some of the 5/8 GA ones were having issues

Where as the 3/4 are turned out on a lathe from 5/8 to 3/4 - so better to go with 3/4 as the turning gets rid of any potential out of roundness

regards

Hi Alex, no problems, you're welcome.

I've used Trident a few times and they do a good job.

If you have a Rover, you should have no problems. They have a slightly different lower bar design, made to clear larger engines. (Actually, larger fuel tanks if you want to be pedantic!)

Tyler, you're right. The GA Spares 5/8ths clutch halves suffered from a manufacturing fault.

Trident's are unaffected, as they make their own.

Looks like 3/4 it is... price is about 295 for a b&s, which is pretty good I think

Thanks for the tip
Who is the engine deal for, ie: which store ?

It's for The Small Engine Warehouse. It's a good deal, but check out your locals as well. They come pretty close.

Yep as Mystyler said pays to check out your locals, it was handy as Small Engine is mine!
The price is cheaper than you mentioned along with free freight.

Best to join the group if you want to know more.