idle adjustment on a TC40a?

GRI · Jul 29, 2011

what rpms should my tractor be at during idle? can it be adjusted?

Carykong · Jul 29, 2011

I have a TC 35 hydro that idles at 1000rpm. Idle adjustment is under the operators deck,if my memory serves me right. Its too dark to check my tractor. Jinman may chime in with more definitive answer.

wrenchguy · Jul 29, 2011

Usually 950-1050 RPM. It can be adjusted at the right hand side of the engine at the throttle bell crank. You will need two 10mm wrenches to adjust the throttle stop/adjust bolt.

dave1949 · Jul 30, 2011

wrenchguy said:
Usually 950-1050 RPM. It can be adjusted at the right hand side of the engine at the throttle bell crank. You will need two 10mm wrenches to adjust the throttle stop/adjust bolt.

That rpm, 950-1050, is where my TC40 idles, I have never needed to adjust it though.
Dave.

wrenchguy · Jul 30, 2011

Dave,I agree. If it idled properly before something has changed. Throttle cable could be sticking or is kinked or jam nut on idle screw has loosened. Cable retaining bracket at bellcrank could be bent. Many different things can cause an idle change.

GRI,is it idling too low or too high?

jinman · Jul 30, 2011

I don't have anything to add to what Wrenchguy and Dave said except that sometimes the hand fuel lever is loose and allows the throttle to move by itself. Normally this is from high rpm towards low rpm. The lever can be tightened by a nut on the pivot, but the whole cowling under the steering wheel has to be removed to gain access. This doesn't sound like your problem or question, so it can probably be disregarded.

GRI · Jul 30, 2011

it sounds like it idles high but it may be normal. I am going to check today.

thx for all your help

GRI · Jul 30, 2011

mine was idleing high. around 1500. I figured why. the foot throttle cable sticks and prevents the butterfly from returning to the proper position. so i have some adjusting to do. thanks guys

dave1949 · Jul 31, 2011

GRI said:
mine was idleing high. around 1500. I figured why. the foot throttle cable sticks and prevents the butterfly from returning to the proper position. so i have some adjusting to do. thanks guys

Oh, I don't have that problem because my foot throttle linkage got ripped off in the woods years ago :laughing:
Dave.

GRI · Jul 31, 2011

apparently that happened to the previous owner as well as I see the cable had been repaired (poorly) and few strands were binding making it not return to idle.

now time to get a part # and see how much NH wants for one of those.