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Joined: Aug 2015
Posts: 26
Novice
Thanks Paul. So I doesn't matter if it is broken, as it was only a breather tube. Yeah.
Do you know where I can find information on setting the fuel line screws, been trying but no luck.
Also need to try and source a cotter pin for the clutch of my mower where it goes onto he engaged be shaft.
Cheers.

Joined: Nov 2013
Posts: 6,938
Likes: 304
Forum Historian
Hello Brendansarah15
I feel engine competency is required here.
The link to the HK25-30 has an operator manual (sent above).
It includes carby adjustments, but a carby clean and inspection is needed.
Do you have competency to do this?

I suspect a flogged out clutch requires some images for Mod BB to access.
We need to look at the crankshaft and clutch body condition.

The SB's did have a cotter pin; later clutch bodies had square head screws.
https://www.outdoorking-forum.com.au/lawn-mo...ott-bonnar-clamp-pin-a453894?cPath=&

Please advise us.
-------------------------
Jack

Joined: Aug 2015
Posts: 26
Novice
I'm not going to lie, I don't have much knowledge about motors, but am capable of cleaning out the carby holding tank and the fuel tank, will give it all a clean out tonight and see how it goes. I'll take the motor off and check the shaft to make sure it's not damaged, and will try and get a close up pic of the clutch itself

Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
Hi Brendansarah15,

I'll take it from here as this thread has probably gone far enough without it running round in circles. I've been a tad unwell and thus why I haven't engaged much on the forum as of late. Thanks Jack for persevering with it.

The Kirby HK-25~30 can be a bit of a handfull at times with most of the issues being related to the carby and a flogged out butterfly shaft which allows air to slide past the butterfly when it shouldn't. If this is the case your only option will be to replace it with another carby via eBay as they are cheap enough through that avenue.

Once you send us some close up shots of the clutch and related items I'll be able to assess what needs to be done.

I gather you are in Melbourne as that's where you bought the machine from in the first instance.

Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
Hi all,

I've just had a look at the photo which I've corrected and notice that the broken piece of orange painted hose is merely a breather hose that is normally connected to the underside of the air filter housing and as such is nothing too much to concern yourself with. It's a sort of Positive Crankcase Ventilation set up to feed fumes from the engine back into the air intake

The carby requires a good degreasing and then I would like you to feel how much slop there is in that shaft that has the linkage attached to it at the top of the carby body.

Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
Joined: Aug 2015
Posts: 26
Novice

After all of that,it was to no avail, once I took the clutch cone off I've discovered a bit of trouble. The engine shaft has bit chips of it. The back of the clutch housing is chipped off,
The key way that was inside was badly damaged.
Looks like I'm up for a new engine and clutch half.


[Linked Image]
[Linked Image]
[Linked Image]

Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
That clutch body is totally shickered and I would now be rather sceptical about the integrity of the engine mounting rails to see if they have stress fractures within them or not, but with the look of the output shaft and the clutch condition it's highly likely that you're in for the long haul here.

Clean all the grease and grime away and please take some close up shots of the areas around the 4 engine mounting holes.

Going back to your engine, it all depends on what you are chasing as an end result. Is it an all original looking mower of just a fully functional mower to use as a daily driver. Once I know the answer to that question only then will I be able to answer the questions in the right direction for you.

Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
Joined: Aug 2015
Posts: 26
Novice
I think if I've come this far and have to buy a new clutch housing, I would put a new engine on it, save a heap of potential problems, with the old Kirby
The engine shaft measures 15.88mm does is that a 5/8 shaft. Or 3/4.


Pics of both the rails.


[Linked Image]
[Linked Image]
[Linked Image]
[Linked Image]

Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
Hi BS,

Well sadly what I've suspected is there to see and that is a stress fracture in the most prominent mounting position, that is the front right engine mount. I will say though that I've seen much worse and you've gotten off lightly with it being a twin rail machine. Most twin railers suffer much worse and are at the point of complete rail failure.

I feel that yours could be easily repaired by grooving out the fracture that's visible and Mig welding it. The trick is to keep heat to an absolute minimum as it will distort the rail and then its curtains for the chassis.

You will have to find yourself a competent welder that can stand behind his work and not just a mate that can bodgey it up and destroy it in the long run.

While I'm writing I've noticed from your photos that you have something that's a tad unusual and that is it's a Series 2 machine but is still running the 3 piece rear roller. One of the major changes with the S2 machines was that they opted to go to a 2 piece roller just like the 17 inch machine but yours clearly still has the earlier unit installed. The other thing that is different is the reel bearing sizes were larger in the S1 machines but when they went to S2 they reduced the bearing and carrier to suit the smaller RLS5 bearing as they considered the 20 inch machine to be a domestic mower and not take any part in the commercial field as previous 20 inch machines did.

I'd really like to know what size reel bearings you have and if you have the larger units then you must treat those carriers like gold as they are no longer available. Yes you can retro fit back to the smaller size if you have to which is the only good point I guess, but one of my original carriers suffered a crack and luckily I managed to get someone to accurately TIG weld and rebore the bearing size, thus saving that carrier but I had it done at mates rates and if I didn't have that option I to would've had to retrofit back to the smaller size as the costing would've outweighed the part.

While I'm at it I'll just give you a rough date to your machine. It is either a very late 1972 into 1973 built machine. The evidence is from the twin brass plates attached to your machine as can be seen in my photo below.

[Linked Image]


Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
Joined: Aug 2015
Posts: 26
Novice
Well that is a pain to say the least, going to end up costing a bit I think.
I'm governed by what your Think is best to do with the rails,
Although would i be able to take it to a fabrication place and get a new solid deck made for it and just transfer the corresponding holes onto the new piece, as I've noticed a dip in the rails, and if I purchased a new engine roughly weighing 12-14kg I'm worried it will fracture.
I have dismantled the whole frame and labelled all parts. I'm not going to take apart the 3 rear rollers, as I'm not to sure how too for one pull it apart, and then put it back together the bearing s seem to be okay as the spin reasonably well
I will soak the bearing carries in degreaser and clean them up, hears hoping they are in good condition.
I've been able to locate a decent second hand Honda engine, I've been told it's a 3/4 shaft what would that be in mm. As I've measured the shaft on the Kirby and it measured 15.88. And according to my caliper it says 3/4. I thought 3/4 was bigger then that.
As the clutch cone is not salvageable I will need to order a new clutch half, but unsure what size I should be getting.

Pics of the reel bearing.
Cheers.


[Linked Image]
[Linked Image]
[Linked Image]

Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
Hi BS,

A 3/4 shaft is around 19mm while 15 is 5/8. Most of the new engines all have the 19mm PTO shaft and thus you would have to purchase the 3/4 inch Clutch Half.


Those bearings from the reel are the earlier size large ones which are a bit more expensive than the more common RLS5 bearings used in the smaller model machines.

As far as replacing the rails with a solid deck is concerned, "DON'T GO THERE" unless you are an engineer wizz like one person on here did and boy was that a mammoth task with a great outcome, but he went the opposite way as he was returning a bodgey solid deck back to its original format of being a twin railer.

Those rails can be easily pressed back into line by a competent person using a good press. I've done quite a few for various people, but I'm in SA while you're in Melbourne. As I suggested a good welder will be able to solve that stress fracture for you and once its all back together running true you'll find it will not induce the massive vibrations like that previous clutch half did. You are just so lucky that you've caught it in time.

PS if you get bored check out the following thread in this link.
https://www.outdoorking-forum.com.au/forum/ubbthreads.php/topics/79816/SB_20%22_twin_rail_to_singl.html#Post79816

Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
Joined: Aug 2015
Posts: 26
Novice
Thanks for the help. I'll get onto somebody to weld up the fracture and hopefully straighten out the rails, will he have to drill a hole at the end to stop the fracture going any further. Hopefully I'll be able to purchase a clutch half and the associated screws and key way. Then purchase a new Briggs engine.

Joined: Aug 2011
Posts: 2,998
Likes: 16
Former Moderator
Hi BS,

No need to drill any holes as its not a windscreen in a car.
Just make sure when any press work or welding is done to the chassis that you leave the sole plate installed so as to keep the integrity of the assembly while doing the work.

Cheers,
BB.


I live a 24 Hour lifestyle, but every now and again I seem to fall asleep, well at least that's what my wife tells me.
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