The Combine Forum banner

1 - 10 of 10 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter #1
My 1680 is dropping below 2450 rpms and causing the alarm to sound. I've replaced both filters, the lifter pump up on the side of the motor, and the electric pump down on the side of the machine. None of this has solved the problem. When it starts to alarm i can slide the throttle forward and the rpms come up and it runs like it is supposed to. I'm wondering if the the throttle linkage has moved and the combine cannot run up to full rpm. The rpms are around 2580 when at full throttle. It only drops below the 2450 when the machine is loaded and pulling a hill. Anyone have any suggestions?
 

·
Registered
Joined
·
2,233 Posts
thought top rpm was 2650, might be wrong, what does manual tell ya for rpm, yes cables at times need to be adjusted, cummins or ih engine, need more info, scott.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #3
This combine has the cummins in it. The manual says that the recommended rpms were 2550 but i was thinking that when we first bought the machine that it ran around 2650. I need to check the linkage to be sure that it hasn't moved. What is the best way to go about checking that and making the proper adjustment? Thanks for the feedback.
 

·
Registered
Joined
·
77 Posts
How many hours on the 1680??? 2600+ probably governor in the pump. Gone thru lots of pumps and injector at this age and older
since the fuel no longer has the lubrication it use to. The ppump shop I use say they put a torque capsule in the pump which make it more responsive in pulling conditions. Also check cam on
rotor pulley to make sure cam are not staying in one place, if the bushings and cams cannot move it will take alot of power and will soon ruin the rotor belt, just something to look at too.
 

·
Registered
Joined
·
159 Posts
The operators manual for my 1680 with the cummins engine says high rpm without a load is 2700 to 2750. That is what the service manager says it should be also. I run mine at about 2730.
 

·
Registered
Joined
·
11 Posts
Discussion Starter #8
Yeah looked at my manual again yesterday and it said 2700 to 2750 high idle without load. It was running around 2550. The lever on the pump wouldn't even hit the stop at high idle. Loosened the bolts and adjusted the lever. Now it runs at 2700 high idle. It'll still be about a month and a half before we start shelling corn so i won't really know if that fixed the problem till then. If not then I'll check the governor on the pump. Also I'll definately check bushings on the rotor pulley to be sure that they travel freely. Just put that rotor belt on. Those don't come cheap. Thanks
 

·
Registered
Joined
·
94 Posts
When you check those bushings on that rotor drive make sure the ramp they ride on is smooth and not scalloped from the bushings only wearing in one place. Had a 1480 that the ramp was scallopped and the bushings wouldn't travel along smoothly to apply the additional tension to the belt. After 3 belts and a lot of head scratching replaced torque unit for $1,300 and haven't shred another belt since.

John
 

·
Registered
Joined
·
159 Posts
I would recommend a Quality Brand rotor belt. I put one on my 1680 and have had excellent results with it. They have kelvar in them and are lighter and stronger than the Case belt. I went through 4 Case rotor belts in 500 acres of wheat 2 years ago.

We rebuilt everything on the rotor and made sure it was all lined up properly and still had a belt go in less than 200 acres. I got a Quality Brand belt and I am still running on that belt. We have harvested over 3000 acres of wheat, rye, oats, corn and gratin sorghum since we changed the belt out.

The dealer warrantied the belts as they had several other customers with the same problem but as you know it is no fun to change a rotor belt out when it is a 100 outside and your working next to a motor that is at 200+.
 
1 - 10 of 10 Posts
Top