mannerRM250

Member
Jan 21, 2010
2
0
Just picked up a a used RM250. Bike is wicked fast but first gear has a very short range. Once on 2 or 3 it has a much wider range. Guy I bought bike from said it was jetted for the track and that is why 1st gear is short. Any way to tweek the bike to have a longer range on 1st? I welcome any input thanks
 

IndyMX

Crash Test Dummy
~SPONSOR~
Jul 18, 2006
5,548
2
Amo, IN
I don't think jetting has much to do with how long first gear is.

I'd discount pretty much anything else he said. First of all, you don't jet a bike for track.. You jet for atmospheric conditions, fuel and whatnot..

You're not likely to find many MX bikes with a very long first gear.

Your bike has at least 4 more gears for you to use. I have to ask, why the interest in a longer first gear?

Even on a tiny Arenacross track, first gear isn't a requirement.. I rode all day Sunday on a very tight indoor, never left second.
 

wake_rider

Member
Feb 21, 2007
481
2
I rarely use granny-gear even on tight trails and tracks, but you might want to check out what sprocket set up he has. He might have changed the sprockets out for lower gearing in order to have a set up more geared for torque, but it would have nothing to do with jetting as jetting only effects fuel/air ratio and has no effect on the transmission or the aspect ratio of your gearing whatsoever...
 

whenfoxforks-ruled

Old MX Racer
~SPONSOR~
Oct 19, 2006
8,129
2
Merrillville,Indiana
Both the who needs 1st and whats the gearing now come to mind. If you need more 1st, bigger front or smaller back sprocket. 1st is for someone over 200 pounds, newbies, or riding on the street. Where you have the exhaust valve preload set will effect this also. Adjust the hit later is what you seemingly want. Get on it! Vintage Bob
 

_JOE_

~SPONSOR~
May 10, 2007
4,697
3
I found 1st gear to be very dangerous on my 02 RM. Second is a much better choice. I used first to load it into the truck and try and free it if I got stuck. Even second would rip by in heartbeat. Just learn to use second gear and keep a finger on the clutch if the speeds get real low.
 


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