i have an 89 lt250r with the mods below.will going from a 12 tooth front sprocket to a 13 tooth front give me a noticable top end.i would like to get more out of the lower gears(1 and 2) they have plenty of bottom end and are over too quick.i would like to strech them out a little with out drastically reducing the bottom end.also,when i jet for 40:1 will i notice a power increase?im at 20:1 right now.

 

anybody even have a 13 tooth on their lt250?

 

Yea needaR I changed mine last year.
I always thought the same thing ,loads of bottom end.
Shifts so quick
It made a diff on mine(92 lt) I had 13 42 gearing with 20 in. holeshots out back.
But major winter rebuild this year.
Im going with 12 - 40 gearing Its a little higher than 13 -42 3.23
12 - 40 3.33 --------------- 12 - 42 3.50
its tough to find the right set up.

 

i just want it to make the gears a little longer.i think im gonna try 13/42 and see what happens.

 

hey there ive got an 88 and im running 12f 39r with 18inchrear tires and my top end is about 87mph..i also seem to have plenty of low end also. but yes it burns through gears in a hurry...

 

My 91 has 13/42 gears with similar mods to yours(they are listed on my gallery page). It had those gears when I got it so I can't say that it's overall better than the stock ratio but I was real happy with it's performance overall so I didn't change them. It does around 70 with 18.5" FastTrekkers.

 

I run 13/45 w/22" ohtsu and I love it but I do alot of hill climbin'. I ran 12/42 and 12/45 last year with 21" Mud Sharks and hated it. I went with the 13 tooth on front for the simple fact that the 12 tooth is hard on chains. I think the tire change made more impact than the gearing though.

 

i just went out and bought a front sprocket.how do you guys get yours on?did you move the axle or undo the master link in the chain?i couldnt find the master link so i had to take the bolts out of thte axle and move it to get some slack so i could get the chain off.

 

I would do as you did since the chain will need adjuster for the new sprocket size.

 

Loosen the bearing carrier like you would to tighten the chain, except go the other way to loosen it.

I was running 14/42 gearing with 20" bandits and had good top end but had to shift alot in the trails. Just this weekend I switched to a 13T sprocket and I lost quite a bit on top. Haven't been to the trails yet, tho.