I bought a '90 kx 250 a while back, and it was a bit of a dog to be honest. I've spent quite a lot of money on it, including a full engine rebuild, but I've finally come to the conclusion that I've bought the wrong bike ! I borrowed my son's XL125 last week, and although it was a lot slower, I had a LOT more fun. I only ride woods and sheep trails, and the KX is too all or nothing for me. What I need to know, has anyone fitted a four stroke engine into the KX frame, what was it, and how hard was it to make it fit ? I'm reasonably competent, and have access to some machine tools. I look forward to any replies, sarcastic or not ! Thanks all.
Can't handle a 2 smoke !
- Thread starter sherrif
- Start date
MONKEYMOUSE
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- May 10, 2001
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I bet it can be done. You would absolutly need to be able to weld thoe, no motor would bolt strait up execpt for anouth 90's KX motor. As for what motor to youse I wouldent know. Get mesurements of where all the mounts are and fine a motor with mounts close to it. See if you can get it to work. Will be a sweet bike if done.
bclapham
LIFETIME SPONSOR
- Nov 5, 2001
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ok, so you come from wales and you ride about on a KX looking for sheep, and you are worried about sarcastic comments!:)
If you feel the bike is a bit all or nothing, maybe you can tone down the engine a bit, for example try an extra head gasket or try a real heavy flywheel weight.
it rapidlly gets expensive swapping motors, and it sounds like youve got a rebuilt engine that would be a shame to get rid of. Keep riding it, once you get a bit more bike time i am sure you will learn to love that bit of 2-stroke heaven!
cheers, BC
I thought of something else that might help.
What is it that you like so much about the old 125?
I doubt it is the suspension. The light weight?
I can understand what your saying. I have an old XL 185 Honda. The bike is very low and easy to touch the ground on. That is all. Nothing about the bike is decent.
If you figure out what specific things you liek about the 125, it would be much easier to recommend soemthing else.
I have always like the easygoing nature of the 4 strokes, but I hate the 300 lbs of weight that goes with them.
What is it that you like so much about the old 125?
I doubt it is the suspension. The light weight?
I can understand what your saying. I have an old XL 185 Honda. The bike is very low and easy to touch the ground on. That is all. Nothing about the bike is decent.
If you figure out what specific things you liek about the 125, it would be much easier to recommend soemthing else.
I have always like the easygoing nature of the 4 strokes, but I hate the 300 lbs of weight that goes with them.
chrishorton
Member
- Nov 25, 2002
- 21
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My Dad rides a DR 350 and wow that is a cool bike. You can ride it however. It'll take you where ever you want however u want. Foreal Hes like 45 and loves it. Perfect old man bike haha jus messin. but no I love ridin it its a fun bike for all terain. i would definitly recomend it to you. Please don't mess the 250. If you did that then you wouldn't get any money for it if u wanted to sell. Foreal. jus get a different bike. Save you the trouble.
jaguar
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Just disable the power valves so that they stay in the closed position. That will keep it from having such high peak power at high revs.
Also you could put in a smaller carburetor, say 5mm less than what it has now. Also you could put on a countershaft sprocket with 2 teeth more.
Also you could put in a smaller carburetor, say 5mm less than what it has now. Also you could put on a countershaft sprocket with 2 teeth more.
- Nov 5, 2002
- 55
- 0
Thats what you get for buying a Kawasaki :P
I would agree with the clapman, there is a lot of things you can do to tame the KX. First you might want to get a fly wheel weight, next a pipe and silencer. A couple of the guys I ride with have KX 250's one has a FMF pipe and the other has a PSI. The PSI is much more user friendly the power comes on low and pull smooth with a nice hit toward the end. The FMF pipe hits hard, I don't like it in the woods it is to hard to ride.
The other thing is the power valve most of them are adjustable and can also help smooth out the power, also you want to make sure it is working or it will have a nasty hit to it. For the type of riding you are doing you might want to soften the suspension and raise the forks in the clamps a little. I wouldn't give up on the KX so easy they are nice bikes, but I would agree they are no XR 250. I think the XR 250 is one of the most under rated bikes out there, I would like to have one just to beat all those whinny KDX riders, maybe then they would realize the bike isn't as big of a bargin as they thought it was.
The other thing is the power valve most of them are adjustable and can also help smooth out the power, also you want to make sure it is working or it will have a nasty hit to it. For the type of riding you are doing you might want to soften the suspension and raise the forks in the clamps a little. I wouldn't give up on the KX so easy they are nice bikes, but I would agree they are no XR 250. I think the XR 250 is one of the most under rated bikes out there, I would like to have one just to beat all those whinny KDX riders, maybe then they would realize the bike isn't as big of a bargin as they thought it was.
jaguar
~SPONSOR~
MikeyG you are way off.
I have a KDX200 and have rode it with the valve actuator disconnected so I could move the valve actuator by hand just to see what it's like and how important valve position is to powerband. It didn't DETONATE or the piston crown shatter. jeesh, I know a KDX isn't a KX but the same applies.
Also I use a 12 tooth countershaft sprocket for MX and a 14 tooth for the street. It won't move with 2 teeth more? Pu-lez
But really I don't want to fight about something not really important. He'll probably just sell it and get an XR which he should do if he wants pudgy power.
I have a KDX200 and have rode it with the valve actuator disconnected so I could move the valve actuator by hand just to see what it's like and how important valve position is to powerband. It didn't DETONATE or the piston crown shatter. jeesh, I know a KDX isn't a KX but the same applies.
Also I use a 12 tooth countershaft sprocket for MX and a 14 tooth for the street. It won't move with 2 teeth more? Pu-lez
But really I don't want to fight about something not really important. He'll probably just sell it and get an XR which he should do if he wants pudgy power.
