The lawn mower thread

[mik]

@Jobbo I have just realised yours has the same engine as my Mountfield (see page1).

I am jealous of your variable speed control.

[Jobbo]

It does indeed - the GCVx170. I think I was expecting the 160 but Honda must have updated it in the last few years. My model was discontinued for 2022; the HRN replaces it but it’s a bit bling in comparison and has a partly plastic deck.

[mik]

If you get bored, I’d be interested to know what RPM it is running at max speed? (The “giri” app seems to give reasonably reliable readings)

[Jobbo]

I’ll try it - the revs don’t seem to change with the speed though, not sure how the drive system works but it must be some sort of primitive CVT.

[mik]

Interesting. Wasn’t expecting that. Probably not worth measuring rpm then tbh.

[jamcg]

https://hondanews.com/en-US/power-equip ... ive-system

Quick google brings up this

[Jobbo]

https://hondanews.com/en-US/power-equip ... ive-system

Quick google brings up this

So it is - a cone system. Like the old Dafs

[Jobbo]

Interesting. Wasn’t expecting that. Probably not worth measuring rpm then tbh.

I did a measurement when I was mowing today - 2860rpm or so, I think. Giri seemed very keen on telling me it was twice that but it didn’t sound like over 5000rpm and I’m guessing it was picking up something going at twice the crank rpm; cams, perhaps?

Used the mulching function quite a bit today to try it out. It worked pretty well on the dryer grass but not so well on the thicker stuff at the back of the house. It definitely requires a slower drive speed; you get trails of clippings if you whizz around at top speed when mulching. So I don’t think it’s quicker than doing the lawn with the grass box even taking the regular emptying into account.

[mik]

@jobbo - that sounds right enough then - mine is 2900rpm fixed according to the spec sheet.

I assume your speed control doesn’t change the blade speed, so I guess it makes sense that it’ll cut better at slower speeds.

[Jobbo]

I think the blade is geared directly to the crank so yes, it wouldn’t change with drive speed.

Does make me wonder whether I should try running it at a few hundred rpm more. Do you have a link to the governor spring changing guide?

[mik]

Does make me wonder whether I should try running it at a few hundred rpm more. Do you have a link to the governor spring changing guide?

Don’t think I ever saw one tbh - I can take some pics though. I bought a new governor spring so I can change back and forth (takes 30secs with a pair of pliers.

[Jobbo]

Do you just get an original spring and slacken it a little?

[mik]

Tighten (ie shorten) it a smidge.

[mik]

@Jobbo Some images.

With “Fast Road & Rally” spring fitted.


First tweak I did took it to about 3150rpm. Made a further tweak so this sets it to approx 3380rpm.



New spring part number if you want to be able to revert back to stock. In case it’s in for warranty repairs, or if you crash and the insurance send an engineer out to assesss it ….

[Rich B]

my ///Mountfield that managed to break a bit on its first mow (requiring them to send a new bit out) has never missed a beat since in 5 years of hard labour. I gave the spring a little kink a few years back to give it a few extra rpms and I top up the oil about once a year, but that's all the attention it's had. I'm Impressed tbh.