RPC primary and secondary setup

racer7x

Active member
Here are some pics of the RPC primary and secondary setup.
Also a Bender conversion shaft and another RPC Cat secondary.
These are going on my 92 for grass and my 96 for asphalt.
 

Attachments

  • 100_0272.jpg
    100_0272.jpg
    202.8 KB · Views: 419
  • 100_0273.jpg
    100_0273.jpg
    221.9 KB · Views: 412
  • 100_0274.jpg
    100_0274.jpg
    218.3 KB · Views: 398
  • 100_0275.jpg
    100_0275.jpg
    207.3 KB · Views: 392
  • 100_0276.jpg
    100_0276.jpg
    220 KB · Views: 395

Belt

I think an 8BU is 52 plus inches. Remember, the cats had a conventional crank and the Yamaha's driver clutch is forward with the gear reduction in front. To run a bearcat secondary on a stock max4 chassis, you need to move the motor back about 3/4 to 1 inch and use the 8BU belt. Dean, with those standard A/C clutches, you will use the stock 8BU belt with the stock motor mount location
 
Last edited by a moderator:
Skinner said:
I think an 8BU is 52 plus inches. Remember, the cats had a conventional crank and the Yamaha's driver clutch is forward with the gear reduction in front. To run a bearcat secondaty on a stock max4 chassis, you need to move the motor back about 3/4 to 1 inch and use the 8BU belt. Dean, with those standard A/C clutches, you will use the stock 8BU belt with the stock motor mount location
Thats what I thought..:eck02:
 
FYI.. the 750/800 engines are based on the tz GP bike engine minus the tranny cavity. The bike took primary input to the tranny at the center to avoid crank twist, just as the sled does. All the shaft at the front does is transmit power to the primary clutch @1:1 (clutch/crank speeds equall, not like the apex were engine speed must be reduced to safely drive the clutch) hence it's not a reduction gear, only a countershaft turning in the right direction.The motors run backwards as evidenced by the rewind rope feeding at the top instead of the bottom.
Hope I cleared this up
 
Reduction

The reduction is like .95:1. If you put a degree wheel on the crank and mark the primary shaft, give it a rev, you will see that it is not a 1:1. The primary shaft is underdriven by about 3/16" per revolution of the crank
 
Skinner said:
The reduction is like .95:1. If you put a degree wheel on the crank and mark the primary shaft, give it a rev, you will see that it is not a 1:1. The primary shaft is underdriven by about 3/16" per revolution of the crank
Thats what I thought, .95 to 1 ....
 
Dean,

If you ever get time........would you mind taking some pics of the re-machined end of the jackshaft, with the keyway and a scale (tape measure) for reference?

Thanks,

Ken
 
Gentlemen..I stand with my tail between my legs...after I saw Skinners post I just had to investigate considering who it came from.
Degree wheel on output shaft/ D' indicator in cylinder showed me a 8 degree loss in one roll...next time I'll think before I spew ..my apologies to anyone I may have ticked off..
 
  • Like
Reactions: Ken
Ken, here's a few pics with a ruler.
 

Attachments

  • 100_0331.JPG
    100_0331.JPG
    68.8 KB · Views: 249
  • 100_0332.JPG
    100_0332.JPG
    72.2 KB · Views: 243
  • 100_0335.JPG
    100_0335.JPG
    75.4 KB · Views: 239
  • 100_0336.JPG
    100_0336.JPG
    58.8 KB · Views: 239
  • 100_0337.JPG
    100_0337.JPG
    79.8 KB · Views: 240


Back
Top