Why has my lawn tractor got such low power?

[ejenner]

I did buy it new a few years ago so nobody else has messed with it.

I was disappointed with the power from the beginning and I did specifically go for the v-twin 600cc motor so it would be angry enough to be entertaining. But if they've dampened it down for noise and emissions reasons then maybe it is no more effective than a single-cylinder machine.

[Frankenhealey]

Feb 15, 2023 10:04:33 GMT ejenner said:

With it being EFI it is potentially controlled by an ECU and if that's the case then there's a possibility it's governed by software and that would be likely impossible to workaround without hacking the ECU or changing it entirely.

Get on some Lawn Mower Racing forums. If any one knows how to do it they will.

[ejenner]

I did try that a few months ago but the forum I found was very quiet and my question never got answered so I forgot about it for a while.

[Frankenhealey]

What's your model number? It starts with 13

[vitesseefi]

Feb 15, 2023 10:04:33 GMT ejenner said:

With it being EFI it is potentially controlled by an ECU and if that's the case then there's a possibility it's governed by software and that would be likely impossible to workaround without hacking the ECU or changing it entirely.

Head skim, Megasquirt and re-map.

And maybe a scatter-guard……

Never underestimate how much power a hydro-drive can mop-up

[Frankenhealey]

Feb 16, 2023 13:09:11 GMT vitesseefi said:

Never underestimate how much power a hydro-drive can mop-up

You could change the motor out for something better. Here's a Deutz T216 Turbine connected to a Cub Cadet hydrostat

[nalesutol]

That should be enough power and you can incinerate the cuttings at the same time :-)

[ejenner]

Feb 16, 2023 13:09:11 GMT vitesseefi said:

Feb 15, 2023 10:04:33 GMT ejenner said:

With it being EFI it is potentially controlled by an ECU and if that's the case then there's a possibility it's governed by software and that would be likely impossible to workaround without hacking the ECU or changing it entirely.

Head skim, Megasquirt and re-map.

And maybe a scatter-guard……

Never underestimate how much power a hydro-drive can mop-up

Megasquirt did cross my mind! I can see this getting a bit out of hand though... so more likely with it looking like a big job I'll just leave it.

[dodgerover]

Under load can you see if it physically opens and closes the throttle butterfly with the governo - Same as an older tractor? you used to be able to have a piece of string tied to the operating arm to override the governor for a few extra rpms on the road...

[ejenner]

It does look as though the throttle rod does not go straight to the throttle. There are some other springs and cams involved in the process of transmitting the throttle lever input to the motor. I've noticed it most when reducing RPM... it seems to stick at high RPM and pull the revs down very gradually after you've lowered the throttle. Maybe it's some sort of dampening mechanism to prevent sudden changes of throttle position causing running problems.

[vitesseefi]

I expect the governor is still mechanical, just like carb-equipped ones.

EFI system likely to be somewhat rudimentary. Still magneto ignition or is that controlled by the management system too?

[ejenner]

Looks like current EFI. With a single bosch style injector at the throttle plate.

[Tazzy]

Speeduino seems like a sensible route

[ejenner]

Feb 23, 2023 19:35:18 GMT Tazzy said:

Speeduino seems like a sensible route

Looks good. Probably is the answer but not the sort of project I've got time for with everything else I have on my list.