86 Transmission VS 89 Transmission

[250Renvy]

I just picked up the last parts to complete my NEW bottom end build, unfortunately all the parts are 86 as that was all that was available new.

Since I've always run 88/89 stuff and never mixed and matched parts, I was wondering what the real difference is in the transmissions - especially if you mix it with a Long rod crankshaft?

There is 1 tooth difference on 3 of the gears - what difference if any would I notice and should I bother upgrading to the newer gears?

[red88r]

All I have heard and can remember from having them apart is that a 86 tranny will outrun the the 87-89. On the top end. I personally wouldn't bother upgrading to the newer gears.

[fourtrax_r]

if i can remember correctly the 87-89 had a much higher top speed than the 86. 88-89 was even higher than the 87 because it came with a 38t rear sprocket instead of the 39t on the 86-87. the only major difference in the trans is 5th and 6th gear on the mainshaft and countershaft. there were other small differences but nothing you couldn't mix and match. you just can't mix and match 5th and 6th gear.

[Langbolt]

If you're running the Stock displacement 246cc then you'll notice a wee bit of lag when shifting from 4th to 5th...then 5th to 6th.

With a big-bore it's not as noticeable.

If you're gonna have it ported and some aftermarket goodies like a Pipe & bigger carb you won't notice it as much.

I swithched my '86 to the '87-9 gearing and it just makes it a closer ratio gear box

Also if you're trail riding it.....you won't really use 5th and 6th as much....and when you do down the roads.....it'll have the faster edge on the '87-9's

:devil: