Case 900 PSB High Idle

Cash4Toys

Member
Helped a friend install a rebuilt PSB pump, runs fine but per an electronic hand held tach it will run 2000 rpm. 500 rpm over the rated 1500 seems excessive to me. Seems to me later ones ran 1650 and then the 401's went 1800 but this is the 377 cu in.
Can someone tell me if the feul delivery is also increased by rpm? What is the corelation between high idle setting and fuel delivery setting? I do know how to set the high idle stop behind the cover on the throttle shaft or would you just leave it as is? Certainly don't want to shell it out over reving it.
 
"diesel tech" can tell you for sure. the high idle might not have been set correctly when it was rebuilt.
 
"diesel tech" can tell you for sure. the high idle might not have been set correctly when it was rebuilt.
them tractor pullers crank them up like that, but i would be ok with 200 rpm over stock but thats a bit excessive for continuous use on that big engine.
 
On Case PSB pumps it MIGHT have the speed control stop cam off one tooth on the fine splined throttle control shaft, that will throw the high speed stop screw setting off. Best remove the two tin covers and see what's going on, shaft and cam splines MIGHT be stripped too from wear which allows the cam to slip on the shaft.
 
I understand what your saying. Where the high idle/low idle cam is under the cover, is that made to fit in only one position on the shaft? If not I guess I'll just have to be extremely careful of it current position.
Does full throttle at high idle at 2000 increase feul delivery at say 1500? Wondering if I shouldn't just pull the pump and have the rebuilder make certain it is set right.
 
I understand what your saying. Where the high idle/low idle cam is under the cover, is that made to fit in only one position on the shaft? If not I guess I'll just have to be extremely careful of it current position.
Does full throttle at high idle at 2000 increase feul delivery at say 1500? Wondering if I shouldn't just pull the pump and have the rebuilder make certain it is set right.
Speed won't increase the fuel delivery. I'd try turning the high speed stop screw in and see if it has the range to set lower. That cam has fine splines and might need removed and turned to lower the speed range. That can be done with pump on engine if one is careful.
 

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