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

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.