JD 1250 problems

[john_g]

I have a JD 1250 MFWD. with a Yanmar 3T95J engine and a JD 100 series loader. 5323 hrs on machine. Engine was said to have been overhauled before I purchased but seems to lack power. Black smoke when under load. I have all new filters including air,oil,fuel,and hyd. There is a lot of soot build up in the exaust manifold. Could the injection pump be set improperly? The "no tinker" lead seals to adjust the pump have been "tinkered" with. Thanks

 

[pfoxy]

Yep, sure sounds to me like somebody that didn't know what they were doing "turned it up" for ya.

Choice B would be that the injectors are worn and need to be replaced.

Either way, sounds like time to visit a competent diesel mechanic to me.

 

[kubmech]

John, unfortunately some guys take that adjustment apart when they tear-down the engine not realizing what they are messing with. There is no guidance in the manual for adjusting the setting. The best way I have found to deal with it is to count the threads you have showing. Turn it in a little and see if you get an improvement. If it gets worse then go the other way. If nothing you do seems to change anything then it could be something else. Then you can set it back where you found it and let the deisel mechanics handle it. could be something else, but that is probably where I'd start. Don't forget the simple stuff like, the 3ph lever all the way up causing hyds. to run over relief and load the engine.

 

[rdln]

Kubmech, are you saying that the 3ph should not be lifted all the way up when not in use?

 

[kubmech]

Should have been a little more clear. Normally when the 3ph is all the way up the feedback linkage will send the valve back to neutral. If it's out of adjustment the hitch will stay pressurized causing the relief valve to open and rob power from the engine as well as overheat the hyd system and will eventually damage the pump. This is a relatively common problem and if you don't notice it, will send you off in the wrong direction thinking there is an engine problem. Depending on how the loader is plumbed it will also give you problems with FEL operation. I have seen people replace hyd. pumps, loader valves, even one engine rebuild. Imagine the look on there face when you reach over and drop the 3ph and the problem goes away. It's a sneaky little gotcha that's easy to fix once you know what it is.

 

[john_g]

I looked at different posts about jd and injection pumps. The only adjustments I can get to seem to be the fast idle. There is a cover behind the hand pump: is there anything I can adjust there? This tractor starts very easily even in cold weather. By lack of power I mean it will not go up a 5% to 7% grade in it's highest gear without stalling. Any suggestions about what I can do with out taking it in to a dealer. Also is there any info out there that I could read about turning up the injection pump.