OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Underneath the Honda HR194

Having recently become a Honda guy, I'm looking for any information anyone may have on the early evolution of the Honda HR194 with 4 height levers, sometimes called the "commercial model".

Note that the base, handle, and many other features are different from the single height lever HR194.

Here is a sort of generic HR194 commercial (from ebay) viewed from underneath:


Note the bar blade, which seems to be fitted to all Honda walk-behind mowers unless they have a U in the type number: HRU has swing back blades, HR has a bar blade. If I'm wrong about that, please tell me.

The mower in the picture has no grass chute, no rear stone shield, and a full-circle part of the base casting that drops down to protect the crankshaft from getting things wound around it. This seems normal for most mowers so far. However, let's look at my similar HR194:



It obviously has three major differences from the ebay one: it has a pressed steel grass chute, or "scroll guide" (crudely panel-beaten by me), a top-pivoted rear stone shield suspended from the axles of the back wheels, and a large gap in the crankshaft-protecting circular shield. You can see that this gap in the circular shield is not due to damage, the casting was made that way. I've removed the cover ("roto stop cover lid") that attaches to this gap to take that picture. Assembled it looks like this



If you go back to the first picture of the generic ebay HR194 commercial, you can see a couple of the mounting points for the grass chute. They even look as if they have been tapped, so I'm guessing the grass chute has been deleted along the way, as a tenant's improvement. I don't know about the suspended stone shield, but you can see that the axle extensions it mounts on are present, and so are the deep cutouts in the sides of the base to accommodate those extensions. This ebay mower clearly has a full-circle crankshaft-protecting shield as part of the base casting, there isn't a bolt-on section of the shield, so apparently access to the roto stop without removing it was no longer required.

So, there seem to have been running changes in the design of the base of the HR194 commercial. Can anyone tell me anything about this, such as when, why etc.? It may help me to date my mower. The HR194 commercial first went on sale in 1983.

A story about underneath the HR194 would not be complete without covering the much more common (in Australia anyway) single height lever version. This is still called HR194, but has the same base as the single height lever HR195, HR196, and the later HRU versions of the same mowers.

Here is a general view of one of these bases from an early single-lever HR194 that had been scrapped by a contractor:


Look first at the three areas circled in red. At the front of the deck there is a fair-sized hole (about an inch by 5/8") where a stone looks as if it came right through and kept going. Bar blades and thin aluminium decks make a poor combination. Where the front axle mounts in the base, you can see there is quite extreme wear, to the point where the reinforced part of the base is worn right away, and the axle has hacked into the thin part of the base, so the axle was not positively located any more. Third, in about the middle of the wheelbase, the vertical skirt of the base is cracked for about an inch and a half. I see no signs of impact on the inside of the skirt, so this appears to be a fatigue crack: the mower was probably wheeled over a lot of rough ground, and that heavy Honda engine stressed it too much.

All three of these problems are more or less characteristic of the single lever Honda base. You will find some version of some of them on the majority of ex-contractor 19" Hondas.

The area circled in blue shows another serious design defect of the Honda base, but in this case, it has not caused a failure on this particular base. However, I'll show you another identical base where it has.

This is an HRU195 base:

The red circle shows the end of the crack, which runs back around the corner onto the vertical surface. The crack is 5" long.

This crack seems to have occurred because the contractor wanted to avoid the usual problems with the front axle and the vertical crack through the skirt, so he wheeled his mower across rough ground with the front wheels lifted in the air. Seems like a great idea if the base had been well designed, but it wasn't. Look at this picture:

You can see that the outer edge of the deck of the base is bevelled for about 3/4", perhaps to make it look nice (which in my opinion, it does successfully). Now let's see what the corresponding part of the base looks like underneath:


As the blue oval area shows, for nearly all the way around the deck, the natty bevel on the top is matched by a corresponding bevel underneath, so the base is the same thickness as it is elsewhere, and there is not much of a stress concentration where the deck meets the rim . However, look at what happened to the last couple of inches, circled in red. No bevel underneath, so in the corner where the deck meets the skirt, there is a very small radius, and a high level of stress concentration. Worse, if you look at the picture of the top of the base, you can see a very small radius where the vertical, lateral panel at the back of the mower meets the deck, introducing another severe stress concentration that meets the one underneath the deck. This is where the crack started on that HRU195.



Incidentally the mower is not very old and has not done very much work: wear to the iron cylinder liner is only 0.0015", where on an ex-contractor Honda that has just begun to blow blue oil smoke and is therefore retired from service, it is 0.002". This HRU195 was completely smoke-free, which ex-contractor Hondas seldom are. It looks to me as if its business career was cut short by the cracked base.

So, there are a couple of lessons to be learned here. First, never run a single lever Honda over rough ground with the front wheels lifted. (As well as being likely to crack the base, this often breaks the handle, even on other types of mowers that do not have design weaknesses in the base.) Second, take a close look at the base of any single lever Honda you are considering buying.

In case anyone is interested, here is what I did to that HRU195 base:


It isn't pretty, and it still isn't nearly as strong as if that base had been cast with the underside bevel extending right to the end, as it should have been.

Is that threaded into the alloy or do you have nuts on the oustide??

I would have done it the other way, threaded the metal brackets and bought some button head bolts the ground them flush on the inside.


Actually i would have just bought a brand new base for $99 off eBay. He has them listed up now.

The bolts are threaded into the aluminium, and where it is single thickness aluminium, they have nuts on the outside as well. All bolts are loctited. (The aluminium seems rather crudely cast, with huge grains and many "sinks", which implies low strength. Pressure cast aluminium tends to be brittle anyway, because high fluidity alloys must be used.) Bolting from the outside is viable for the bolts that currently have nuts, but not the ones that disappear into thick aluminium.

I was not attracted to aftermarket bases, for various reasons - probably mostly because they don't have Honda moulded into the front, but also because throwing $100 extra into a home mower doesn't seem sensible to me. I priced a new genuine base at $350: a lot of money for something so badly designed and made.

If the base fails again - which doesn't seem all that likely in suburban home service - I can still upsize the bolts and run them from the outside as you suggested, into the same brackets tapped out. Ideally I'd use heavy steel brackets both inside and outside, but that would look awesomely ugly. I may also mill out the trashed left front wheel area of the other (HR194) base shown above, and bolt in a replaceable chunk of aluminium, to take care of the recurrent chopping out of the left front wheel support. That problem is caused by the bell crank that the wheel mounts on: the single lever height adjustment system Honda uses is inherently a base-destroying concept. Note that the 4-lever base shown in this thread has all of its wheel mountings in as-new condition, despite seeming to have done even more work than that single lever HR194.

Incidentally Bob, that GXV140 engine on the HRU195 does seem to have had a leaky exhaust valve, as I guessed. (If I'd been wrong, I probably would never mention the matter again.) The seat was black all the way around, and so was the valve head in the sealing area. The whole valve head showed signs of overheating. Two minutes lapping with coarse compound cleaned it up, and when I tried it yesterday it started first pull for a change. I may have an as new engine that will last about 106.9 years in suburban service. Fortunately or un-, I probably won't.

Truth be known, had you drilled the ends and kept an eye on it you could well have been watching something for nothing.


That single height lever things is common to all mowers like that. The worst for it are the steel base victas.
There is constant pressure on that axle piviot via the realy rod from the back.

I did drill the ends of the crack Bob, and two other points along the way where the crack had started to breed offspring. I always do that. If that had been done when the crack was only an inch long, and the previous tenant had stopped running over bumps with the front wheels in the air, it might have been sufficient, but a 5" crack is pretty serious stuff.

Yes, Honda's single lever height adjusting system probably isn't much worse than other similar systems, the problem is that it seems most Hondas are used by contractors, and they see a lot of service before they are junked out. With the wheel mounted forward on a bell crank, the other (vertical) arm of which connects to a link that runs horizontally backward, all of the upward force on the wheel translates into an almost equal forward force on the axle pivot. That wouldn't necessarily matter if the axle were supported in a drilled, closely fitted hole, but because of the cranked axle joining it to the right side front wheel, it can't be in a hole, let alone a fitted one. It goes through a U shaped recess, and is loosely held up by a spring clip, so it is free to bounce hard against the front of the recess every time you hit a bump, and to spring up and down while it's doing it. It looks very similar to a laboratory wear-test machine, in fact.

All mowers use pretty much the same system. MTD uses a different setup but thats a steel base, its all under the base and such a thing would not work on just about any alloy base mower.

Basic maintinace, if the wheel retainer clips where kept tight and the bushes kept good the setup would last a lot longer before eating itself.





I suppose if the home owner wants the ease of single lever adjustment thats what they get.

The same system could be made to work, at a price, if they just used the Honda rear axle mounting system on the front as well as the back. The axle mounts up rigidly and is bolted in place on both sides. At factory cost, probably less than $10 extra per mower. That is about $30-40 at retail though, and I suspect not many people would pay it.

Here is the solution some ingenious contractor adopted (ebay picture):



This is a worn out HRU215 for sale on ebay. If you look at the red circle, you can see that the base has worn so severely that the front axle has moved forward more than an inch. If you look at the yellow oval, you can see that it moved all the way until the center part of the axle hit the front flange of the base, and couldn't move any further. Looking at the green circle, to make this possible the fore and aft link of the height adjusting mechanism has been extended more than an inch by welding in an extra bit. After that, you couldn't adjust the height any more, but the axle couldn't move any more either.

That base has been used for so long that the front of the scroll that confines the air and grass under the mower, has been just about worn all the way through and is falling to pieces.

Maybe that mower belongs in a museum of Australian ingenuity.