Increase rpm on mower

[ipbr21054]

ive bought a champion R484 self propelled mower. It’s the same style as in supplied photo.
Today I cut 7 lawns but I feel that I could of pushed it quicker.
Not sure if it was because of the damp grass but it wasn’t due to its length as I cut these 7 lawns every other week.

How can I adjust the rpm to help assist the speed.
There is a throttle lever on the left hand side which has the tortoise/ hair & choke symbol.

Not sure it there is an adjuster on the cable or you need to start cutting governor spring / bending brackets ?

I remember on a label I had seen SV150

 

[Burnerman]

You’ll appreciate that the maximum RPM of these engines is governor maintained, and this can be increased somewhat by careful bending of the linkages.
However becore jumping in there, make sure that the throttle cable is pulling the linkage as far as it can when the handlebar lever is in the full throttle position......it may need to be pulled back at the engine end.
John

 

[ipbr21054]

Ok cheers I will take a look tomorrow.

The self propel works when the other bar is held.
This cable has a knot in it up towards the handle bar. I assume this has been stretched at some stage ?
The self propel works fine.

 

[Burnerman]

Yep, make sure its getting full bore using the throttle lever....Whatever bracket or linkage the cable is connected to, see if you can move it more by hand.
John

 

[ipbr21054]

Hi,
I’ve popped the cover off to show the movement of the throttle lever & it’s carb linkage.
I will show this in 3 stages.

Position of throttle in the off position & this reflects in carb linkage position.

 

[ipbr21054]

Position of throttle just when carb linkage starts to move.

 

[ipbr21054]

This is throttle position just before choke engages on carb linkage.

What do you think ?

 

[Burnerman]

Excellent pictures!
The carb is shown on the full throttle position, as I would expect with the engine stopped.
I think the only thing you can do is to gently twist the bracket that the longer, thinner spring is attached to just to allow the spring to get slightly more tension.
I cant guarantee anything here, of course but the bracket can be bent back again.
John

 

[ipbr21054]

Just an update.
Looking below the air filter I have found the throttle cable adjustment.

It’s just a simple bracket where the cable passes through it and held down but a piece of metal / screw.

Where it is clamp there is say 1 1/2 inches of

 

[ipbr21054]

I assume you mean this bracket ?
If so also bend it in same direction as arrow.

Or do we adjust the cable as per my last post ?

 

[Burnerman]

Slacken the cable clamp bolt and pull the cable back and resecure.....see what happens.
Yes to the second question - just trial and error but Id resist the temptation to alter the springs like most folks do.....they dont go back to original again.
John

 

[ipbr21054]

Ok
I think I will look at cable clamp.

Looking at the throttle lever end there is only one mount hole so basically I’m now going to achieve the same but the other end.

Thanks.

I will let you know how I get on

 

[charliegolf]

I always wish my Mountfield would go faster, for exercise if nothing else. But if I could walk at say 1.5x the speed it is now, will the blade 'have enough bite' as it passes over the grass? Also, isn't (in my example) the blade going to be going at 1.5x design RPM? Any danger there?

CG

 

[ipbr21054]

I have moved the cable in the clamp a small amount and the revs have come up.

I am to use it today so will try and see.

I assume the throttle in the lower position will just be increased slightly.
This will be the same as the throttle is moved from the tortoise to the hare BUT you last bit of movement I assume is the increased part you will notice.

I think the rpm will be the same but the throttle lever will just be in a different place.

Then before the adjustment you run out of lever movement before the choke position you now have that little extra to which the rpm will be noticed.

Will that’s what I think.

 

[Burnerman]

I always wish my Mountfield would go faster, for exercise if nothing else. But if I could walk at say 1.5x the speed it is now, will the blade 'have enough bite' as it passes over the grass? Also, isn't (in my example) the blade going to be going at 1.5x design RPM? Any danger there?

CG

Mowers are set up to be a little on the slow side so the manufacturers can claim reduced noise and emissions. Considering the amount of speed you'll gain, the cutting system will be fine.
John