6600

Any of you John Deere guys also 6600 combine experts? Is it allowed to post a combine question here?

Post away!!! LOL

We are all experts in our minds. LOL

Hey thanks! Not sure what ok and whats not sometimes. My question is - I have a 1970 6600 JD combine- works great yet(not a lot of wheat to cut) but I get too much chaff in my bin; my neighbors have helped me adjust the sieves and they are close I'm sure; Im thinking my wind speed is maybe off? No book on this combine; I don't have a hand held tach; all I can say is the belt is running clear inside(down in) the bottom pulley the fan is on; and about 1/4" from the top of the top pulley.(it is adjustable). Hope this kinda clear- hard to explain. Thanks!

I ran a 6600 like yours for many years......I always ran the fan as fast as it would run.

If you've never ran a 6600, you might check the WOT setting on the engine. If I remember correctly, it should run around 2650 RPMs. It sounds high...and I ran mine for a while before I got a manual and figured out the machine was running way too slow.

I'm sure one of the other posters has a manual and can help you on the engine speed.

Hope this helps.

Ok, but not talking on "engine speed"...but meaning "fan speed" that cleans the grain...the fan underneath the machine. Im very sure my engine is running fine.....thanks.

The engine drives the fan. Slow engine = slow fan.

Hi, Banjoman09: I am not sure if this will be of help to you or not, but I will share of a similar experience we had on our 1976 7700 combine. We struggled for years getting enough wind from the fan through the cleaning shoe. After having the combine for 11 years, and while we were cleaning it up for winter storage, I discovered something on that combine that my dad had recalled hearing in a combine clinic at our local dealership during the first years we had that combine, but never was able to find. He said it was referred to as the "forward air duct," or something like that. If I recall, you need to crawl under the combine and get in between the transmission and the outer shroud of the cleaning fan. Just under the troughs of the conveyor augers and above the fan shrouding, you may find a gap in there that has filled up with dust and chaff. Some machine had this, while others did not, and I am not sure why that was the case. Our was built up with that to the point there was little to no gap in there. The cleaning fan WILL draw air from this, if set up as such. On the sides of the machine, there are two small, square tins that can be removed. Removing these will allow you to see the cross shaft driving the cleaning fan. This will also allow you to see the small openings just below this shaft where the air from this forward air duct is brought into the cleaning fan. There might be dust and chaff built up in here, too. I found this also can be a potential fire trap, particularly if a bearing goes out on that cross shaft. It takes some time with a blow gun, and other tools to remove this build up, if present. What I can offer is that after we cleaned this up, we had a sizable improvement in the volume of air the fan would push through the cleaning shoe, which made our soybean sample look better. I have seen some combines where this was present, and others that did not have it. This might be part or all of your problem, or it might not even apply, but it is probably worth checking into it.

But im not talking about the engine fan..........

Had the same problem on the 7700 years ago. I used a digital tack to find it was not near up the speed. I took the pulley with the adjuster apart and added a few shims to allow the sheaves to be pushed together more to speed it up. Hope that makes since.

Engine drives the cleaning fan, straw racks, cylinder, elevators, everything on that combine that moves!
If the engine doesn't run fast enough nothing runs fast enough.

Hope your just being silly.

There are several things you can check to find your problem. First, as was mentioned, be sure your engine speed is correct. If it is not the whole separator will not run at the proper speed. Next, be sure the crop is ready to harvest. If it is not you will be fighting yourself all the way. Once these two parameters are confirmed then be sure you are completely threshing the wheat but not over threshing it. When the wheat is good and dry the straw should look like you shelled out the grains of wheat by hand and not be ground up. If you are over threshing and the straw is turned to "meal" you will be overloading your cleaning shoe and no amount of cleaning shoe adjustments will cure your problem. If you are not over threshing check your cleaning fan speed. If your belt is worn you may not be able to get the speed you want. Wheat usually requires a lot of air (perhaps not as much as corn, but still quite a lot). You will want the chaffer to be open (to start with) about the width of your index finger or slightly tighter. Don't set it too tight. Set the sieve (bottom screen) about the width of your little finger. Do some cutting and look and check your return elevator. You should get a very small amount of grain through this elevator but you want some chaff, too, and not be all grain. Then check your sample. If you cleaning shoe is set properly the chaff will float out over top of the chaffer (never hitting it) and clean grain will go into the tank with minor amounts of material in the return as mentioned above. If chaff just falls off the chaffer INCREASE the air. If you see wheat on the ground more often than not it is because of too little air, not too much. Also, if your chaffer is set too tight you get the "garden hose effect" where your air becomes pressurized due to too small of an opening. You want air VOLUME, not pressure. Get these things right and you should be able to cut a nice sample. Tell us your current settings and we can help more. Mike

Hey thanks! My RPM is 2625.....has always been fine. My wheat is cut below 13........or 13.5.....chaffer? is which one? There's something to the belt placement on the top belt pulley- the one that adjusts. Should belt be about "flush" with top pulley? I will check the sieve openings. Thanks again.

No - not silly. Not sure where someone came up with the idea my engine is slow? its fine....2625 rpm.......thanks

Ahhh...ok...chaffer is top screen? Thanks

anything will help...even though I have farmed all my life- I was mostly "the hired man" of the family and dad took care of everything; now Im on my own and learning all this- this will help and I will look...thanks much

tach says 2625...should be fine. thanks!

I set the bottom sieve with "pinky" ; the top front part( there are two parts to the chaffer) I set with index finger ; the back part (about 12" wide) is sticking mostly straight up...is this right ?

There are decals on each side of fan that says "Air ducts must be inplace for proper air operation"....and this is??? There are two square holes by the fan- one on each side...the covers for these are not there. About 4 x 6" that you can see in....behind the fan. Maybe it means the "shields" ? which I do have on there.

Do you have an owner's manual for this thing? If not, sounds like you need to get one.

somewhere....lol

Your are right - was also hoping for experience from these guys ; still have too much grain and chaff in return....... moisture is 13.2 so will be cutting tomorrow- if I get this dang thing set right !

I run a 7700 when I bought it I had the same problem. The chaffer sive got bad and I got a new one.The new one was a small grain adjustable sive.The old one was a corn sive.With the new sive it does a real good job.

The guy I bought this machine from was cutting corn with it....I figured they use the same sieve? Is there a difference and how do I tell?

Im even getting parts of wheat heads in my grain bin.....