high idle speed screw?

[ARhine]

I think I have heard it called this? Was reading some in the FSM and it is not talked about to much.



Now that I have a tach I can see that my power really slows down at 2500 rpm or so and goes slowly up to 2900 or so. Have found some mention of turning this screw out a few turns to help with this defueling problem.



Anything to watch out for? Sugestions?



also I still don't get this breakover spring deal either.

 

[Greenleaf]

Ah... ... . where to begin.



The screw is not mentioned because it is "supposed" to be adjusted by a Bosch factory trained pump technician ONLY!!!!!



Ha Ha Ha Ha Ha Ha



Sorry, so anyways it will help. You can turn it to any location you wish. At some point the fuel linkage will reach it's limit and will not alow any further fueling without modifying the trucks linkage. There are several locations where the linkage will require modding. Beware too high engine speeds with out heavy valve springs.



The pump's fuel rod (along side the pump) attatches to the breakover spring lever... . The rod imparts motion upon this lever which in turn imparts motion upon the spring which imparts motion upon the pin (centered between the spring ends) which in turn imparts motion upon the injection pump "fuel control lever" which transmits motion to the throttle shaft.



The BO spring is a shock absorber to the pumps linkage internal and external. The spring never moves in everyday operation. The ends of the spring impart motion onto (against) the pin it rides against.



The spring end(s) wear through as well as the pin.



The only time the spring moves is when(if) there is a sudden load imparted onto the linkage OR the PUMP'S linkage reaches it's max travel and the truck's linkage has not.



GL