250F Kx250f kick start

W

Welllit

Hey guys
New to this forum so forgive me if I don't post properly at first. I've been out of the game for a couple years and just picked up an 09 KX250F. The previous owner was a young kid who said it needs a top end. I tore all the plastics, shock, tank and carb off. So I pulled the plug and started to kick the bike to find TDC. However I will push down and it will go down 100% then the next 40% but it's not looking like it's turning anything up top? Am I missing something? I'm pretty mechanically inclined but I wanted to get a second opinions before I started tearing it down anymore. Any help would be greatly appreciated.
 
SRAD97750

SRAD97750

Moderator
Staff member
WELCOME!
I would put my finger over the spark plug hole and see if it's pushing any air. If not, probably needs valves. If weak probably needs a top end.
If nothing is moving at all, maybe the kick start gears are damaged or incorrectly installed.

Either way, disassembly is free!
No need to set TDC, just get a service manual and start pulling the top end.
-BIG DAN:thumb:
 
Mihylo33

Mihylo33

Welcome!

I think it's a 2:1 ratio(?) so every 2 turns the crank makes the cam turns once. So it will appear to be drastically slower.

Start posting some pics of this bad boy!:thumb:
 
W

Welllit

Here is the bike torn down so far. I'm going to spend tonight doing as you guys said and tearing down the head. Like I said I've been off a bike for 3-4 years but I'm happy to get back to what I love. Thought this would be a fun project for the next few weekends! I'm finding this site a lot more helpful than some others I've tried!
image.jpg
 
W

Welllit

Ok so I pulled the top end off and I believe it wasn't kicking correctly due to the timing because the previous owner was a young kid who didn't know his a** from his elbow and he tried fixing it before selling. I think the timing was way off and looks like it was run low on oil. Where the cams sit seems to be a little chewed up but nothing major. Jug looks good with no scrapes or imperfections. Piston looks ok. I don't know how to check the valves however which I think is necessary and get them to the right spacing so to speak. Any suggestions on where to go from here? I am planning on buying a new cam chain in case this one is stretched and doing a new piston rings jug and top of head and keeping the cams and valves because they look alright. What's my next move fellas?
 
Mihylo33

Mihylo33

Welllit:
Ok so I pulled the top end off and I believe it wasn't kicking correctly due to the timing because the previous owner was a young kid who didn't know his a** from his elbow and he tried fixing it before selling. I think the timing was way off and looks like it was run low on oil. Where the cams sit seems to be a little chewed up but nothing major. Jug looks good with no scrapes or imperfections. Piston looks ok. I don't know how to check the valves however which I think is necessary and get them to the right spacing so to speak. Any suggestions on where to go from here? I am planning on buying a new cam chain in case this one is stretched and doing a new piston rings jug and top of head and keeping the cams and valves because they look alright. What's my next move fellas?
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Here is my best advice on this.
Rebuild the entire bottom and top end. Send the head out, rebuild the crank, new cam chain, tensioner, valves, cam, piston etc etc. It's been my experience that you'll regret it if you don't.
 
W

Welllit

Mihylo33:
Here is my best advice on this.
Rebuild the entire bottom and top end. Send the head out, rebuild the crank, new cam chain, tensioner, valves, cam, piston etc etc. It's been my experience that you'll regret it if you don't.
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That's pretty pricey to to do all at once. What's involved in doing the bottom end? I've never done one on one of these before. Can you give me details on what I would need to buy? Also how much is it to get the head redone? I'm trying to stay within reason. Keep in mind I will probably have the bike for a few rides and get another project.
 
Mihylo33

Mihylo33

Welllit:
That's pretty pricey to to do all at once. What's involved in doing the bottom end? I've never done one on one of these before. Can you give me details on what I would need to buy? Also how much is it to get the head redone? I'm trying to stay within reason. Keep in mind I will probably have the bike for a few rides and get another project.
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Oh I thought you were keeping it to ride.
To do it right about 900 total.
Split the cases, pull the crank. New rod bearings and new crankshaft bearings.
 
W

Welllit

Yeah for now I'm just going to do the top end. Can you direct me on where to get the parts for the best deal and also what parts exactly I will need to do the top end correctly? That would be extremely helpful. I'm having trouble finding any decent prices on anything.
 
Mihylo33

Mihylo33

Welllit:
Yeah for now I'm just going to do the top end. Can you direct me on where to get the parts for the best deal and also what parts exactly I will need to do the top end correctly? That would be extremely helpful. I'm having trouble finding any decent prices on anything.
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Motosport.com and rockymtnatv/mc.com will have what you need.
To rebuild the crank will cost about $150 total. It's the cheapest part. The expensive part is the topend rebuild. It has the most moving parts and to skimp out on just any 1 part will turn that rebuild from 900 to about 2200 usually within hours.
 
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