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Gearing question 49 to 48 or 49 to 51?

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This has probably been discussed at length before so sorry if this is redundant.  I have a 2011 KX 250f and I ride primarily at one track.  The bike came with 50 tooth rear and I remember immediately not liking how quick I ran out of 2nd gear.  I bought right away a 49 tooth rear and that is what I have been using since.  On my primary track there are quite few spots where I wish 2nd would pull a little longer but it's just so busy to shift to 3rd and then right back to 2nd.  I thought I'd go with a 48 rear and that might give me that little extra I am looking for.  There is one spot on the track with a triple jump right out of a corner.  Not a lot of guys hit this jump since it's so close to the corner.  For me I just can't bring myself to go off this jump with my bike revved to the moon like that and I just don't have the speed in 3rd (or the shift would happen right on the face of the jump practically) to make it I'm not sure.  I've seen quite a few guys carted off on this jump so it's a little scary but it makes a big difference in lap times to make it so I'm thinking that a change in gearing might just be the thing to get me over the jump.  Or if I should just consider going way up and being in 3rd a lot more than I am now.  The way I ride now I only have two shifts on the track.  I have heard a lot of talk about the classic bad habit is revving the bike so much and I think I am guilty of it I would probably go faster if I was lugging more in 3rd.  Just wanted to get some advice from you guys who know more about this than me.

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Hello ejlif,

do you have a afetermarket pipe? I had a similar situation on my KX250F and after I had installed an Akrapovic exhaust the bike is great on lines, in few spots on the track where i needed to switch from 2nd to 3rd or 3rd to 4th now i don't need anymore, the exhaust just gave me that extra extension on the engine keeping th eoriginal gears. My suggestions, keep the 49, install a pipe if you don't have one than lean the fuel a few percents.

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Hello ejlif,

do you have a afetermarket pipe? I had a similar situation on my KX250F and after I had installed an Akrapovic exhaust the bike is great on lines, in few spots on the track where i needed to switch from 2nd to 3rd or 3rd to 4th now i don't need anymore, the exhaust just gave me that extra extension on the engine keeping th eoriginal gears. My suggestions, keep the 49, install a pipe if you don't have one than lean the fuel a few percents.

Hi yes I do have a full PC ti4 system and you are exactly right about that good call I also noticed what you are describing when I got the exhaust installed. I went ahead and ordered a 48. If I don't like it ill try a 51.

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Just curious what track is this?  Are you in socal?

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two more things you can try as well is to change the FI/IG map, the stock KX250 2011 comes very rich and if you have the tool or someone who can do it for you for sure it will help a lot. On my KX2500 2011 I had first leaned it which gave me extra power and throtle response, then later I changed the Ignition time, I had advanced it and the bike was behaving litle a two stroke, very quick response which might be what you are loking for to make the triple jump, a negative point is that the bike is more dificult to control and also if you had done any work on your top head then be carefully when changing the ignition time. On my case later on I had returned the IG to zero because I was getting tired faster. Right now I'm riding 13/49, with exhaust pipe and leaner FI, bikes works great and very happy with it.

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Have you tryed railing the corner in 3rd? you could try feathering the clutch all the way through the corner to keep the rpms up and then just pinning it on the exit or try seat bouncing it

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