Honda UMK425 Questions & Answers

Grahame I have the unit if you are still looking for one. my e-mail is [email protected] I am in Brisbane.

Price hovers around $500, to about $450 on sale. I get mine from the big green shed.

Could be a split in the tank, or the fuel line. Does it leak when the tanks half full? On an angle, and if so which angle? Does the fuel stream out or simply drip? If so from which component does it run from? Is it a heavy smell of fuel or just a damp patch that collects dust? You mentioned the bulb being replaced, is it an old or heavily used machine, and has someone overhauled it and not fitted a fuel component properly? From working on older cars, I used to trace fuel leaks back from the fuel tank until I found the source, perhaps try that troubleshooting approach. Too many ifs at this stage to point the finger at one definite thing.

Hi Sam, can you clarify what you mean? If you are talking about the choke lever, it has a detent position when it is raised so it "clicks" in place. If the lever is flopping down from the raised position then something is loose on the choke shaft inside the cowling and am sure your Honda dealer can sort it quickly or somebody mechanically inclined.

Thank you

Use the orange line. 2.4mm. Cuting against rock or concrete will need more frequent bumps to spool line out as it will wear more quickly

Sorry I cant answer this. Best to ensure you purchase from an authorized Honda dealer. Maybe they would know

Hard to say. Could be fuel related. Check choke off once started, fuel is not stale, airfilter is ok.best to get the service shop to check if a problem

Gday, I just read your Honda brush cutter review on Product Review, hope you got your machine going by now but if you haven't here is your fix

1. the Honda fuel filter breaks down and the small bits then get drawn into a internal fuel screen, some Honda filters seem to last longer than others, we have two Honda's, one filter lasted no time at all then blocked the carby screen with the small bits off the filter, the other one lasted a long time.

Replace with a Stihl type fuel filter

2. If the above problem is all O.K there is a very small brass mixture screw in the top of the carby, in the middle of the part that the throttle cable connects to.

Give it a very small tweak anticlockwise while trying to rev it. the Honda will go a lot better.

I had the same problem,it would go full revs for a while then just die as if starved of fuel.If you kept it going at idle for a few2 seconds it would rev up again briefly.
I found that if I loosened the fuel filler cap it was ok, I assume it was some sort of airlock.

Gday Adam

you cant change the direction of spin, but with enough money and parts you could change the shaft, but the cost would be to great. It will be best and more cost effective to buy the model that suits you.

Toddy..................

I would also suggest purchasing a new straight shaft model and sell your other.

I wish I knew the straight shaft spun anti clockwise before I bought my UMK25 loop handle last week :(. I researched everything else on it but that. Everyother snipper I have had over the years was clockwise. Can't get used to it and stuck with it I'd say.

Hi mate, search for my YouTube channel, alexaescht, and find the video about changing to the brushcutter blade on the Honda UMK425. That video shows how to take the nylon head off and you can follow the reverse to put it back on. The biggest thing to remember is that the thread is in reverse, so to loosen the head off, you must turn it clockwise, and to tighten it, you must turn it anticlockwise. Alex.

Basically the only real difference is in the drive shaft; instead of it being made of solid metal, like the straight-shaft versions, it's made of a flexible cable. This allows it to be 'bend' through the bent portion of the outer shaft. Some people prefer the bent-shaft versions because they're generally lighter, they can be easier to edge with and they're cheaper, obviously.
If you're going to do any serious work with it, then I wouldn't go for a bent-shaft one, but if it's purely for doing the lawn edges or similar, then it'll be fine.

On the bent shaft models the line trimmer head spins in the opposite direction to straight shaft models. Although the bent shaft model has the same 25cc Honda motor as your UMK425. The bent shaft Honda is considered the domestic model, I use mine commercially doing domestic type lawns. I find it great when doing lawn edges as I seem to have a more precise control when turning it on an angle for getting that perfect lawn edge.I did have to do a slight modification to the guard as it would only allow a small length of line to protrude from the trimmer head before cutting it off. I think it is designed this way so as not to make the Honda work so hard. Perhaps give it a longer life. I'm sure you may even void your warranty by doing what I do. But saying that, I've used the bent shaft Honda commercially for a number of years and got a very good run from them.

The newer models are not as good as the older ones, like every thing these days. I found when I purchased my new model bent shaft Honda the guard and loop handle were like something off a cheap home brand whipper snipper. My older model Honda bent shaft had a larger guard that had an adjustable blade to control the length of trimmer line. The latest model now has a smaller guard with no adjustable blade. My older model had a good sized rubberized loop handle. The newer model has a smaller, thinner all plastic handle. I was able to buy an older model handle as a spare part to put on my new Honda.
MarkIV The Honda bent shaft in a good secondary line trimmer. You may find you'll use it more than your straight shaft. It all depends on what your trimming or brush cutting.
Regards: Pedro

i usually store mine on a bracket that you can buy from mitre 10, stored vertically engine high, about
2 metres of the ground on the garage wall. other wise you can just sit them down on the base of the strimmer, length ways, To fill with petrol I tip the strimmer on its side, so i can fill to the top.
I've had no trouble with my strimmers over the years,