Northern, where are you locatedIJ, we ran a 2002 claas Mega 204 (series 3) with a 25ft Claas front, this last harvest in Australia. The season was poor due to lack of rain, however we at least got some grain to strip, the 204 came standard with the Claas pressed metal concave. We started stripping oats and the machine worked well, then we went to lupins still not a problem. It was only when we started to strip wheat that the overloading of the sieves started. The pressed metal concave seems to allow to much material through the openings in the concave, thus allowing to much material on to the sieves instead of some of it going over the walkers. I think the "one size fits all" does not work when it come to concaves The wheat was going about 7 - 9 bags per acre and we were down to 2 - 3 miles per hour to stop the grain going over the sieves. We ran the top sieve fully open, the bottom sieve 3_4 open and ground speed flat out in 2nd gear about 6 -7 miles per hour, all this did was run the returns at 70-80% full, too much! the sample was bad by my standards, plenty of chaff, turn fan up to get chaff out and grain went out the back to. We changed to size of the pre accelerators concaves did not make any diferance, ran with the de-awning plates opened and closed did not make any differance. So we slowed down the speed to 2 - 3 miles and closed the top sieve to about 11 mms and the bottom to about 11mm's aswell and the fan at about 1050 - 1100 rpm. sample was good, lose was very low only problem was the ground speed, my 4 month old son could nearly crawl as fast. This was the same situation in triticale, poor capacity. Friend of mine has a 1994 Mega 204 (series 1) that when he got it it had the Claas pressed metal concave in it, he ran it like this for the first year, and had a lot of trouble with overloading of the sieves, and this inturn caused grain being pushed out the back. In the off season he fitted a loewen wire concave to the combine, and for the last two seasons has been able to atleast double his speed and some times more, with little or no lose and a great sample. It is known in Western Australia that the wire concave when fitted to the Mega 204's and 208's get a 20 - 30% + increase in capacity of the machines by just changing from a pressed metal concave to a wire one. We had the dealer out in the padock with us and they tried everything we had throught of,still no luck. Then we got the Claas importer for Australia - landpower out to the paddock, still no luck in getting both ground speed, capacity and a great sample, all at once, both the dealer and landpower were great in trying to get the combine right. We played around with the combine all harvest and put up with it until we finished the harvest. When harvest finished landpower came back to us and offered to fit a wire concave to the machine, which we have since done, i know it will be a differant combine with the wire concave fitted next harvest, if it ever rains! Claas have wire main concaves and wire pre accelerator concaves listed in the parts book for all Mega's and lexion, the price for the mega wire concave is about 10 - 15% more than a pressed metal one. So the cost to fit them as standard whould be nil to Claas. email: claasman68@hotmail.com
