New member from Michigan having trouble with 1978 Yanmar 240 D

[johnisdone]

My hand throttle likes to creep down while I am mowing, snow-blowing, or other activities while using the PTO. It seems to be the worst in the winter before fully warmed-up.

What can cause this?

What can I do to fix it?

 

[deerseeker001]

Welcome from Wisconsin

 

[johnisdone]

Thanks a lot.

 

[johnisdone]

Any idea what might cause the problem I described?