I gave up on mine after a new switch, having all sensors test O.K, checking ground to cab and probably some more things that I've forgotten. Since I only shell corn with it the cylinder speed hasn't been too big of a concern, I just run it as slow as it will go and adjust cylinder to concave clearance to get it off the cob. However last year when we started to shell the old girl just wasn't working right. One thing I noticed right away was too many cobs and husks coming over the shoe, and I have removed my separator beater and shaft and the metal curtain over the raddle, ala Ray Stueckle, so I checked the engine speed with my hand tach and it was O.K. but the motor is older than the combine, previous owner blew engine and got one off of an early l, the one with the Sims or CAV pump or whatever its called on it. I wasn't sure but what we were losing quite a bit once we got into the corn. My solution was to take a Micro-Trak, Calc-an-Acre that I had on my 3 wheeler and put it in the combine. I epoxy glued one of the little flexible magnets that Micro-Trak uses to the pulley on the cleaning fan and mounted a sensor to read it. Besides measuring speed, distance, and acres you can program it to read RPM,s. It will always show a decimal place, 1000 RPM will read 100.0, 950 RPM will read 950.0, but since that fan is supposed to turn at 1000 RPM it is real easy to glance at it and tell where you are at. Sure enough mine was only running bout 910-920 and after doing some adjusting on the throttle cable and stiffening up the bracket at the engine end to get it on 1000 to 1010 it was like a new combine. The same unit could be used on the cylinder. When I get real ambitious and if I get my header creep fixed before next year I may get some more sensors and a switch and fix it so I can check on any of them but that fan shaft is, I believe, critical as your cleaning shoe and walkers and straw spreader, if you're not using a chopper run off of that fan shaft. I hope someone can tell us both the key to making the factory tach work properly but even if mine were all working perfectly I'd still leave my Calc-an-Acre on my fan shaft as it will tell me if that belt is slipping. I also use the same unit on a deep placement fertilizer unit that I "Homebuilt" so it has been a very versatile unit for me. Mine is an older one, a Model 84C which has been superseded by something else so if you have to try that route you might check with Micro-Trak to make sure the new ones will work the same way.If you have a Shoup Mfg. Co. Fall 1999 catatlog they are on page 100. Gary D.
