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Recently my mower started running very rough. After checking the obvious (fuel filter, plug, removed plug in bottom of carb,etc) turns out it was what the manufacturer refers to as the pto switch (blade engage switch). After replacing the switch, the mower only runs at one speed which is about 3/4 speed. Won't rev faster or slower. The throttle cable is moving but not engaging the carb. I can't find a pic or diagram of what the throttle linkage should look like. Any help would be appreciated. '21 year model.

Have one just like it at work. Don't know why it would do that with what you say you have done to it. There is a link going from the governor arm to the throttle shaft with an anti surge spring over it. Where the boden wire (inner wire) hooks into the control arm there is an arm on the backside with the governor spring hooked to it that goes to the governor arm. This setup is kinda funky. You can increase the RPMs by loosening the clamp on the throttle cable and pull the whole thing toward the back of the engine and locking it back down. But when you do this it may make it run faster at idle. If it does post back and I will tell you how to fix it.

Thanks for the reply. I have loosened the throttle cable and moved it both directions with little to no change in engine speed. Quite frankly, I'm stumped.

Can get reach max revs like 3600 with your finger controlling the throttle plate?

Find the governor spring and where it hooks to the control arm. Is behind the control arm bracket and if you move the throttle control you will be able to see it through the square hole in the control arm bracket. You can take a pair of needle nose pliers and bend it to put more tension on the spring. You really need a tach to do this and set the the RPM to about 3500 RPMs can go to 3600.

slomo said:

Can get reach max revs like 3600 with your finger controlling the throttle plate?

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It'll rev with finger control.

hlw49 said:

Find the governor spring and where it hooks to the control arm. Is behind the control arm bracket and if you move the throttle control you will be able to see it through the square hole in the control arm bracket. You can take a pair of needle nose pliers and bend it to put more tension on the spring. You really need a tach to do this and set the the RPM to about 3500 RPMs can go to 3600.

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I'll give it a try in the morning. Is there supposed to be anything besides a spring? I can't see how a flimsy spring would move the governor.

Daveintx said:

It'll rev with finger control.

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Then your carb/throttle linkage is off.

Either a cable is bent, bent up or non OEM or linkage stuff is way off. Finger works to max revs but not linkage.

Look up your carb and linkages at your engine parts list. Somebody has been playing around in there.....

slomo said:

Then your carb/throttle linkage is off.

Either a cable is bent, bent up or non OEM or linkage stuff is way off. Finger works to max revs but not linkage.

Look up your carb and linkages at your engine parts list. Somebody has been playing around in there.....

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I haven't been able to find an engine parts list. Suggestion?

The spring is not very heavy. Those engines have a quiet muffler and the sound may fool you as to the RPMs.

any ideas where I can find an engine parts list?

All toro parts lists are available directly from Toro along with owners manuals + most service manuals
However you need the actual model number off the ID tag and some times the serial as well that of course you wrote down & kept when you bought your mower did't you ?

bertsmobile1 said:

All toro parts lists are available directly from Toro along with owners manuals + most service manuals
However you need the actual model number off the ID tag and some times the serial as well that of course you wrote down & kept when you bought your mower did't you ?

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yes I have both serial and model numbers. Problem being, I can find engine parts but not carb or linkage parts anywhere.

If they are not listed on the TORO parts book then they are an ENGINE makers part .
If it is a Toro branded Loncin engine they Toro have a separate engine service, owners & parts manual on line .
Otherwise it will be a B & S, Kohler , Kawasaki part and on their parts break down .