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ndekens

99 KX 250 questions!

13 posts in this topic

Well I just got back into riding after having to sell my 2003 KX250 for truck tires and shocks.

Found a pretty well setup 1999 KX-250.

Got a couple questions though. Is the 99 motor much different then the 2003 motor? IE will my shop manual for the 2003 motor work for me or is everything gonna be different? Im mainly interested in the torque values for nuts and bolts.

Also (since the 99 came with a busted clutch cable) does the 99 ride much different then the 2003? I ride trails and tight single track.

Its geared 13/50 right now is the gear spacing in the transmission different then the 2003?

I may have a few more questions later but thanks for the info!:ride:

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i know the kick shaft on a 99 is thinner than a 2003 , and i think the transmission is geared dfferent on a 2003, but think alot of the internals are basically the same...i have a 2001 and when i bought it the ownwe said it was a 2003 engine

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Yeah, I think the kick start has already been replaced on this one. The transmission seems to be geared lower then the 2003. Its has 13/50 on it right now but im going to test out 12/50 on it for the single track riding I do but im thinking it might be too low.

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Yeah, I think the kick start has already been replaced on this one. The transmission seems to be geared lower then the 2003. Its has 13/50 on it right now but im going to test out 12/50 on it for the single track riding I do but im thinking it might be too low.

I run 12/50 gearing on my 99 kx250 and your right it is too low. Im going to try 13/52 next. I also only run single track

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The 99-01 KX's becomemuch better single track bikes if you put in a 94-98 1'st gear in them.

Ed

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I run 12/50 gearing on my 99 kx250 and your right it is too low. Im going to try 13/52 next. I also only run single track

Are you constantly pulling the front end up with the 12/50 gearing?

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Does anyone know whether newer kx 250 engines would fit into a 1999 kx 250? Thanks a lot.

Tom

What's "newer"? For starters, the 05-07 engines have a more perpendicular cylinder and a rear head stay.

Are you constantly pulling the front end up with the 12/50 gearing?

I ran 12/48-49 in my 2000's, but like Ed said, swapping out that trans is your best bet if you are going to ride trail alot.

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well basically I bought the bike pretty cheap as a project bike, and i've found that for around the same price as a full rebuild (which it needs) I can get like a 2003 engine with recent rebuild, nice piston, V force 3 reeds etc. I was wondering whether this (and other year engines for KX 250) were faster and whether they would fit my 1999?

Thanks, Tom.

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The 03 motor will fit fine but you need to use your 99 head so the mount on the head works with your frame.

Ed

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Are you constantly pulling the front end up with the 12/50 gearing?

I run 12/52 on my 2000 KX250 when I ride tight woods and 13/52 when I ride more open areas. It works great for me. It makes the rest of the gears pretty short though. The 94-98 1st gear would be nice. I don't have any problem with the front wheel flying up.

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I run 12/52 on my 2000 KX250 when I ride tight woods and 13/52 when I ride more open areas. It works great for me. It makes the rest of the gears pretty short though. The 94-98 1st gear would be nice. I don't have any problem with the front wheel flying up.

I don't have any problems with the front coming up either. As others have mentioned, the first gear is too high for technical trail riding and the 12/50 gearing is a bandaid of sorts but it kills the top speed. Will likely go with the earlier first gear when I rebuild the motor this winter and gear the bike back up

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