This weekend I finally got around to 'upgrading' my transmission pulley size. I got a new job about a month ago and due to the 50+ mile each way commute, barely have time to work on the mower on week days. So it was good to get some work done over the holidays.
The pulley I've been running is a 4.5". I run this with a 87" belt. I ordered a 3.5" pulley with an 86" belt. In order to make this work, I did have to modify a few things. The belt guides which I had made to be adjustable luckily only had to be adjusted inwards a bit. On the other hand, the belt was now running into the shifter in 5th gear. So I had to do some tweaking, heating, grinding, and polishing it to make the shifter go around the belt. The cool thing is that with it in 5th gear ( my racing gear) the bent "U" shape in the shifter now acts as a secondary belt guide, which is nice given the fact that I'm using a single long belt that likes to whack around like crazy.
The transmission, which is a Foote 5 speed hasn't had the oil changed in months. So I changed the oil.The gasket material I used previously was apparently not oil resistant. It had been leaking A LOT of oil. When I took it apart, hardly any gasket material was left. The new sealant I got is specifically for transmission cases.
These are supposed to be the bad transmissions. But interestingly enough, we have 4 guys in our group using them and so far none have given us any problems. Mine is still in good shape with minimal wear. The trick is to put the thing in gear and NOT shift it while driving.
With the slightly smaller rear pulley, the overall speed has gone up to around 45MPH, which is sufficient given that we race on a smallish track. I think the size of pulley now is about as small as I can go without having some slipping issues. This will be the setup I use until the end of the season. Then it will probably be time to modify the mower for a live axle setup.