The Kirby's when running correctly are a fabulous engine, there's no doubt about that but it's the sourcing of carby components and that destructible crankshaft seal design which are the machines real downfall I've always said.
In saying all that, I have complete confidence in you pulling this one down and replicating what you've done with the other engine.
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.
Thanks CyberJack, I couldn't even find this design muffler anywhere. All the U.S versions had a different muffler so I think your right in saying it was a Kirby Aus design. It's a pretty straight forward design and easy for someone to reconstruct now knowing what it looks like, I hope it helps others out as I could of used this information months ago, guess I was lucky to find one complete.
I've been looking through this thread with great interest as I have a SB45 17" with the same engine. Nice job on your Kirby, it looks amazing! I'm about to embark on a similar project and will be happy if mine looks half as good when I'm done.
Anyway, the main reason for my post is that I'm struggling to determine how and where to get a carby rebuild kit for my HK25. I'd be incredibly grateful if you could steer me in the right direction.
The carby kits an interesting one as it depends how far you need to go to replace the gaskets. I think the main problem with the carby on these engines is that their kind of a mixed bread with the U.S parent company Tecumseh/Lauson and Kirby. Although the Kirby is the same as Tecumseh engines theres a slight difference with the air filters and the carb design, maybe CyberJack can give us a bit of a history lesson with the design difference of the U.S version and Aus Kirby if my thinking is correct. As far as I believe you can only get carby kits for Tecumseh/Lauson and not Kirby which means it's going to be a bit missed matched, I have found most of the gaskets are still ok to re use if your carefull the only things I replace is the float bowl gasket and clean the rest up. I still haven't been able to find a float needle the same, as the kits online are different with a spring and a rubber seat which these carby don't use. You can still get the fuel drain kit on the bell housing which I just make my own rubber gasket as it's just a small flat piece of rubber. For reference I order carby kit 631021 and only use the float bowl gasket and nut washer as the rest isn't compatable, some of the other gaskets might come with the Tecumseh engine gasket kit 33233 but I can't remember. The gaskets between the air filter and carb I managed to get from a local mower shop that's been around for 100 years and had buckets of Kirby NOS that I spent hours going through checking part numbers and found only a handfull of parts. If anyone knows of a different kit please share as I would also be interested to know what others order as this is how I do it and know that I had problems doing a complete carby kit as there was no reference. I'm currently doing my second Kirby rebuild as we speak, so if you follow my SB model 38 edger rebuild you can get some more reference as I'm more familiar with the second build as I was with the first. I just ordered these kits mentioned above to do the second rebuild.
The other main issue with the kirby is that the main butterfly shaft wears to the point of leaking air in and as such the engine will hunt up and down continuously and this is just not fixable as these shafts have long been discontinued.
The best you can do is buy a full replacement carburetor off the net and use that. This has been the most common fix to keep these old timers running reliably.
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.
Having read your comments I checked both the main butterfly & choke shafts and both are badly worn. Looks like I need to replace the carby completely.
Bonnar Bloke, would you happen to know where I could source one / what the part number would be? I'm struggling to determine what would be suitable.
I really want to get the mower running so I can check that if everything's working as it should before I strip it all down.
My preference is to preserve the originality of the mower as much as possible, but if I can't get the Kirby going I may just have to fit a new B&S as a last resort.
mandkn, what I would do as a temporary fix so you can determine what else might need doing is plug the holes in the carb body with JB Weld and then drill them so the shaft is a good fit. Sure it may not last but nothing much to loose and it could buy you time to see if something else will bob up.
So I took a punt and dropped into Adelaide Mower Centre yesterday.
My younger brother suggested I should try and find a mower shop that’s been around forever and this place was exactly that. The guy there was incredibly helpful and pulled a carby off of a Kirby engine he had out the back which was in much better condition that mine. I took it home and cleaned it up and the old banger standard on the second pull! Happy days. The only issue now is the fuel tap leaks and passes and the seal on the float bowl drain is knackered. No big deal, I can sort that out later.
The main objective was to get the engine going so I could check all the running gear on the mower, which thankfully seems to all be A1.
