Is this the shut down ?
Yes. The Skinner valve is the electric solenoid and the small air cylinder actuator to it's
right is what pushes on that short lever arm coming out of the top of the governor. That
is the actual shut down lever and you can easily move it by hand anytime. As long as
there is a gap between the shutdown lever and the air actuator push rod you are not
experiencing any shut down lever overriding the governor issues. Your problems lie
elsewhere.
It's also a very good idea to check thoroughly the throttle linkage from the front to the
back to ensure you're getting full travel all the way to the throttle lever on the governor.
It's pretty easy to have accumulated sloppy lost motion prevent the throttle lever from
hitting the full throttle position. Age and rushed mechanics through the years will usually
make this problem hang around and get worse with time. Don't trust anything until you
get in there and verify all the motion from the throttle pedal to the throttle lever on the
governor is being transmitted fully. Once you get this right the bus will seem to have a
new lease on life and you can control it much better with a smooth and responsive pedal
again. Knowing that you are actually achieving full throttle when you need it will give
you confidence and even may cause you to notice other subtle little problems previously
being masked by the sloppy linkage and not hitting full throttle. In case I haven't been
clear the throttle lever is the one just to the right of the shut down lever. It's the one
with that cable end attached to it. I Strongly suggest that you make the effort to acquire
an engine book for it which you can find for reasonable prices on ebay. It will explain
it for you in great detail and help you gain confidence in your own knowledge on what
to do and how the parts work together. The same goes for the MCI book too. You need it.
If this doesn't fix the problem then you have something wrong in the governor and control
rack systems inside the heads. This will require a seasoned DD 2-stroke mechanic who
can troubleshoot and repair whatever is going on. There can be many reasons and only a
qualified DD engine guy should be allowed to open it up and diddle around with your
engine and governor, or you could end up with many more problems than you have now.
You've been warned. Good luck.
