Maintenance & Technical > KX250 / KX125
KX250 Woods Conversion
Dan_AKAL:
I've got this 99 250 and I'm just gonna turn it into a woods bike this winter. There is a method to my madness here. I'm trying to get cross country racing started up here in the frozen tundra and plan on putting together a hare scramble next year. I bought this 250 from one of the guys who races MX and I am using it as a bench mark for the rest of the racers. Anyone here will recognize this bike from the MX track and when I am finished they will know what they need to do to get their bikes off road worthy. Anyway I have a few questions maybe you guys can help me with since this is my first Kawi. My previous experience is Yamaha and KTM.
I've read all of the stuff a KaToMer's web site. Thanks! This has been a big help. Now things like hand guards, skid plates, rotor protectors, radiator guards, and tuning the suspension are must haves. I'll put on an 11 oz. fly wheel weight and then see what I need to do with gearing. I already have Procircuit pipe, triple clamp, and shock linkage. The bike runs good but it is definately an MX bike. The throttle is more like an on/off switch than a throttle.
Here are some specific questions.
Anything I need to do to the Power Valve? At present it hits hard and a little early for my liking. However, I'll need to make more of a determination on this after I get the FWW.
How about reeds? Should I look here for different ones? I mean other than making certain they are functionally sound.
Someone please tell me about a torque spacer. I have no first hand experience with these. Only read about them. Besides going between the reed cage and the engine what do they really do?
Any comments on this would be greatly appreciated.
Dan
Rick:
Dan,
The hard hit on power delivery is probably a manefestation of the pipe more than anything. Most motocrossers use a pipe that does not work as well for off road, so first thing to do is find out what pipe you have.
Next, you need to make sure your power vavle is working properly, so pop that cylinder off and clean the power valve. This may be your only problem.
To continue, DO NOT add a flywheet weight to a 250, as I don't think you will like the result. The reason it works for some (old guys, right Paul) on a 500 is because the 500 has the power to run the weight. While I do run one on my son's KX125 in some situations, it is meant for to solve the complete lack of bottom end on a 125 for deep sand corners, a problem that is not present on a 250.
Run a NGK BR8EVX plug in the 250. More expensive, but you will not be disappointed.
You don't need a reed spacer on a 250, so save the money.
In a nut shell, the 1999 KX250 works well without spending a lot of money. Focus on suspension, getting the power valve cleaned up, running the right pipe, and installing a stabalizer and you will be happy as a clam. (hand guards, skid plate, etc. are a given)
Good Luck
Rick
mikesmith:
Good points,but with the pipe you can run a longer silencer (you need a spark arrester any way),the longer the silencer will soften the hit some.Id give yourself some time on the bike after you try Ricks tips and you will probally grow to like it.My 500 is ridden in everything (including very tight single track) and I only canged gearing,pipe,v-fource, power-now and I love it to have a "hit".
Dan_AKAL:
Thanks for the info. There isn't much wrong with my bike as it is. However, getting it somewhat tamer would help. I could race it like it is but it is pretty snappy.
My bike currently has a Pro Circuit pipe and silencer. From my best determination it is a Works pipe and I'm not too sure about the silencer other than it is difinately a PC. I thought about a FMF Gnarly pipe as I think the PC Works is more of a MX pipe. However, I don't know that there would be that much difference. Seems as though PC has a lot of experience with Kawi's so I think that I would rather stay with PC but other than the Works pipe there doesn't seem to be a lot of options for my bike.
Rick you are the first person I have heard say not to add a FWW on my KX250 for the woods. Sure seems like it would stablize things some. Speaking of stabilizers you mentioned installing one on my bike. I am assuming that you mean a steering dampener.
I'll do a top end this winter so that will encompass the power valve. It probably is dirty.
Although I may not add a reed spacer just what does this thing do? I have heard them called torque spacers. Not really sure that I understand what would be gained by lengthening the intake on the downstream side of the reeds.
Thanks Again
Dan
mikesmith:
Well as far as the reed spacer you already said what it does, increase the intake area for more crankcase volume resulting in a better charge.I think pulling the tips of the reeds back helps flow somewhat,there $27.00 or you could make one.I have only run a fly wheel weight on my wifes 85,not sure Im putting one on my 250.But unlike the 500 you have options on differnt weights for the 250,Id try like an 8oz,if you dont like it sell it.As far as the pipe Id run it,I think its a good pipe for most any type of rideing.And a Scotts stabilizer is on my 250 wish list!You know what works for one guy may not work for another, so get ideas from other riders,but go with what works for YOU!
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