Arbtalk.co.uk | Discussion Forum for Arborists

Firstly I would like to thank Spudulike for your wise advice with chainsaws that you share with all on the forum, it is both interesting and informative.

This is a slight derail and because of its content.

Can you help with this off topic request, We have a Honda rotary mower HR194 and the clutch is stuck i.e continually engaged and will only run as a direct drive (it rotates with the crank) I had it apart and could not find a problem. I guess something with a fine tolerance is worn, but I don't know what.

Best regards

Tintin

OK. The clutch drive mechanism is engaged via the lever on the gearbox that the cable attaches to. The drive pulleys on the crank and on the gearbox are always in constant rotation so that would be correct.

Disconnect the cable from the gearbox and then see if the drive disengages- if it does, then it's possible the internal cable has seized either due to lack of use or fraying. If it's the cable then simply replace it.

If the gearbox drive is still engaged once the cable has been removed then manually move the engagement lever on the gearbox. These can seize or even get twigs and debris caught in them which prevents the lever disengaging when the cable tension is released.

If the cable is fine and the drive lever seems fine, then it's an internal problem with the gearbox. The gearbox is a sealed unit and therefore internal components are unavailable. Only replace as a unit, but on an HR194 which is a very old model the cost (if still available) would be extortionate.

Thanks for the good rep - only ever had one of these apart, this had the opposite problem, the gewarbox couldn't be engaged - turned out to be the actuation lever had sheared off where it clamps on to the gearbox shaft - think Pleasant is about right, seized up cable or damaged gearbox.

The guy I fixed the mower for said it nearly yanked his arms out of their sockets - did a bit of work on the carb as well

I might be on the wrong track here, and if so I apologise for derailing. I wonder if Tintin is meaning the BBC ( blade brake clutch) rather than the trans clutch, causing the blade to be rotating all the time the engine is turning.

These are far more likely to sieze, I have never seen a trans clutch stick on on a 194, but there is always a first time.

If its the BBC it will mean that the clutch is remaining engaged all the time and the brake is not being engaged.
Could be... Siezed, or out of adjustment cable, ... Worn or broken actuator arm,.... Friction pads on actuator worn or missing,....clutch pads rusted together,.....blade carrier centre bearing siezed.

If it is the trans clutch, then it is repairable but may not be worth it, the bits are not cheap as the others have said, but the gearboxes are not sealed and all parts are available. Most likely place for trouble would be the selector fork shaft siezed in the bushes.

There are 2 trans gearboxes, one type for the 4 wheel variant and one for the rear roller. Both are shaft driven from the engine, so no pullies or belts involved.