250R 6th gear question 86-89

[bobizzle]

i have an 89' bottom end and i put a 86' transmission in it. when i was looking at the 250r manual, it shows two different part numbers for the 6th gears. the one for 86-87 & a different one for 88-89. does anyone know what the difference is in the two years. i did not sit down and count the difference in teeth. has anyone else noticed this, and will this work in the application im running.

[atvmxr]

so long as its all 86 gears you will be fine. 5th and 6th have fewer teeth on the 86-87

[fearlessfred]

the ratio is closer together on the 88/89. you will definitly notice the difference (from 5th to 6th )

[bobizzle]

sorry to take so long to respond. moved... what kind of difference is there between the 86-87 and the 88-89on the sixth gear... like a longer gear faster gear?

[bean #310]

sorry to steal your post but i thought 86 was the only yr with 6 gears and 87-89 only had five

[speedfreek]

Originally posted by bean #310
sorry to steal your post but i thought 86 was the only yr with 6 gears and 87-89 only had five Nope, my 87 has 6. 1 down and 5 up.

[twopump78]

85-89 all had 6 gears... the air cooled '84 only had 5

[Dave83]

Originally posted by bobizzle
sorry to take so long to respond. moved... what kind of difference is there between the 86-87 and the 88-89on the sixth gear... like a longer gear faster gear?
88-89 lower geared in 5th and 6th

[speedfreek]

Originally posted by Dave83
88-89 lower geared in 5th and 6th Lower numerically?

What kinda mph difference would this equate to on top end?

[D Bergstrom]

Originally posted by speedfreek
What kinda mph difference would this equate to on top end?

I downloaded a quad calculator from another website that a guy put together years ago. He took the gear ratios/final drive ratios from various quads and inputed them in. This way you can pick the quad you want, change sprocket sizes , tire sizes, rpm, etc and get the top speed. He had the 86 and 87-89 250R's listed. Per the calculator, with 13-38 sprockets, 20" tires, and at 9,000 rpm, the 86 would do 78.1 mph in 6th gear, while a 87-89 250R would do 75.1 mph. Of course, this is based on gear ratios, does not include friction, wind resistance, etc, but it is something to compare. I guess you could call the 86 transmission more of a "wide ratio" gearbox.

Doug

[bobizzle]

damn well i will be using this motor for a trail bike then. i will use my 89 trans for my drag bike.

thought the 89 was made to go faster in 6th with stock sprocket tire setup.

i have used this calculator a while back. with the 86 with a 12 front and 401 rear and 20 in tire, i think i got the calculator to 98mph or somewhere around there. i just needa send off my cylinder for port and polish now.

cant wait to fire up the r and run it.