[Veselin Kolev]

The gear reduction in the AM planetry is 3.67:1. The no load speed of the FP I use is 20,000 (I dont think this is the 6V, because my team replaced all of ours with 2004 FPs). The gear reduction on the FP motor brings its speed down to about 5500 RPM which is a good mate speed with the CIM, of course as long as you use the same motor pinion.

However, what are you trying to do exactly? As Sanddrag said, a drive train with 2 CIMs and 2 FPs running through the KOP? If you use the 2004 FPs (the ones that dont burn out) you will actually be getting less power, so there is no reason why it wouldn't work. If you are using the 2005 FPs (the ones that burn out rather easily) it will be a little more power than a CIM, about 60 watts per drive train. However, if you use the '05 you also have to limit its speed as Sanddrag said, to match its speed with the CIM, so you might not be getting any more power than a regular CIM. Also, you have to take into account the inefficiency of the AM planetary reduction.

If you are using two 2004 FPs and two CIMs for your drive train, you should be absolutely fine.

Hope that helps.