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View Full Version : does anyone have a big red manual? if so I need some info.



conig
09-01-2004, 05:17 PM
I have been trying to figure something out for modifying my big red. to determine the drive differences between a 250sx and a big red.

the final drive of a 250sx is 4.969 I found this info on page 64 of a scanned online copy of the manual under specifications. If you have the manual please take a look at this page assuming all 1985 manuals are the same it should be in the right hand column. I've spoken with others who would like to know this as well.


If any one cares to know assuming gears are limiting your top end and they do have the same ratio the 25 vs 22inch tire is 9.5% faster and equates to a 6.3 mph increase or decrease( 25 to 22 =- 6.3 22 to 25= +6.3)
I just played with threetire calculators converting standard to metric and pluggin in as needed to get these figures.

just some needed info to plan my future steps.

Seabass
09-02-2004, 03:28 PM
I've got both manuals at home...I'll try and get some time tonight to get some answers for you.

conig
09-02-2004, 03:43 PM
thanks man. Its greatly appreciated.

Seabass
09-02-2004, 09:27 PM
Here goes...

85' Big Red 250ES ---- 85' 250sx

Primary Reduction : 2.500 -------- : 2.407
Final Reduction : 5.683 ------- : 4.969
Gear Ratio, 1st : 2.388 ------- : 2.000
2nd : 1.608 ------- : 1.400
3rd : 1.178 ------- : 1.069
4th : 0.906 ------- : 0.848
Super Low : 4.083 ------- : 3.615
Reverse Gear Ratio : 7.898 ------- : 7.784

I'd love to swap these engines once...
Hope this helps.

conig
09-03-2004, 10:26 AM
thanks man so there definatly different, now to look for a rear pumpkin wih gears for my red.