Honda UMS425 Bent Shaft Questions & Answers

I cannot answer this question, because the UMS425 does not have a grease nipple.

Hi, I'm not quite sure what type of spool head you're using, is it the genuine Honda spool head which I gave away a very long time ago. I'm Sorry without looking at the spool head and fully understanding the problem I cannot help you.

Yes the genuine honda one for 425U

As far as I can tell you can't get a wire brush cutter for this model... Only the next model up(UMK425) have the removal head that can be upgraded(I just bought the UMS425 and the line system is infuriatingly bad so I think I may take it back and get the UMK

There is a flexible cable shaft inside the bent shaft that you can apply grease to. However the greasing might not help the vibration if indeed the source of the vibration is elsewhere. Try removing the head first and see if the vibrations persist before attempting to grease the internal shaft. Greasing the shaft involves removing the entire head assembly at the end of the shaft which is two allen keys that you will find there.

I applied liberal amounts of grease to my Honda UMS425, but the vibrations persist. I think my issue is the end of the shaft where the spinning head attaches to - I think that component is out of balance, but there doesn't seem to be an easy way of solving this issue.

Try new Carby kit

New fuel line and in tank filter. I had the same problem, changed carb, plug, air filter and nothing. It would idle ok but would stall anything over quarter throttle, and 15 minutes of running. Changed the in tank filter and it's gold again.

No oil leak is normal

The needle on the rotary valve of the carburetor needs to be adjusted, most likely out (anticlockwise) as it seems like it may be running lean on idle. This often happens when the internal carby parts harden from E10 fuel, or it is an older machine. Later model machines require a specialised tool to do the adjustment, most mower shops toss the carby and fit a new one as adjusting correctly is a specialised skill.

Thanks Craig, I was thinking of replacing the carby. Quite cheap on EBay but gave it one last go as I was getting annoyed with the grassy edges. I readjusted the throttle cable ignoring the 1~3mm idle free-play and low and behold it started idling. I added about 10% Metho to the tank to deal with the methanol residue and so far so good and will continue doing this for a while. If this occurs again a new carby is on the cards. Cheers

this happened to me the first time i reloaded the line,I had wound the line on back to front.Wind it on in the right direction and no problems.

Your best bet would be to ask Honda themselves.

I have used mine at many different angels from flat right up to 90 degree and it was fine.

Hi Greg, Yeah, I have had no problems using at any angle including upside down and 90deg doing edge trimming. If the fuel level is low in the tank, the fuel pick-up(even though it is on a flexible hose) might not sometimes be immersed in fuel and that would be the only time I could see you having a problem. The carbys in these small engines don't rely on a float in a bowl arrangement and hence will work at any angle.

These engines only hold a small amount of engine oil(less than 100ml) that is getting splashed around everywhere and don't have a sump that can dump a whole lot of oil on the underside of the piston if inverted.

I have had my UMS425 bent shaft brush cutter four about 4 years now and most of the time it has been used upside down to do my edges and never has it missed a beat, so just do it and do not worry about it.

I purchased a new Speed Feed head from my Honda supplier (Parsons in NSW), 72560-UMS-OW4, which works really well (didn't have a chance to test it until now). You can feed the new line in without taking it apart and it bump feeds the line really reliably. Only around $40, pretty much the same as the non Honda heads.