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Download the underlying Excel Spreadsheet

  KLR 650 Ninja 250 Concours DRZ 400/DL650 DL1000
Stroke in MM 83 41.2 58 62.6 66
Calculated Stroke in Inches 3.27 1.62 2.28 2.46 2.60
 
RPM Piston Speed FPM Piston Speed FPM Piston Speed FPM Piston Speed FPM Piston Speed FPM
1000 545 270 381 411 433
2000 1089 541 761 822 866
3000 1634 811 1142 1232 1299
4000 2178 1081 1522 1643 1732
5000 2723 1352 1903 2054 2165
6000 3268 1622 2283 2465 2598
7000 3812 1892 2664 2875 3031
8000 4357 2163 3045 3286 3465
9000 4902 2433 3425 3697 3898
10000 5446 2703 3806 4108 4331
11000 5991 2974 4186 4518 4764
12000 6535 3244 4567 4929 5197
13000 7080 3514 4948 5340 5630
14000 7625 3785 5328 5751 6063
KLR Ninja 250 Concours DRZ DL1000
The following maximum piston speeds are from the book, Performance Tuning in Theory and Practice, by A.G.Bell.       Note: Numbers in red 
  with underline indicate 
Stock  Motor       -       3,500 fpm       (cast crank, stock rods and cast piston)       approximate redline
Heavy Duty Motor  -     4,000 fpm       (forged crank, peened rods w/ good bolts, forged piston)       
Drag Racing Motor -     5,000 fpm   (forged crank, alum rods, lighweight pistons, etc.)      
KLR = 83mm       
Ex250 = 41.2mm      
Connie = 58.0mm      
DRZ=62.6mm