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2009-Post Blown Head Gasket

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What's up guys, I've been looking on the forums for a few days for answers to the problems I am having with my bike. I came down to it being the headgasket. As well as got other very useful important information. So the bike is a new, to me, 09 kx250f. So the day I got it I was riding around my woods, fairly hard, and I blew the head gasket. So I tore the bike down and replaced the head gasket as well as the base cylinder gasket while I was at it. Replaced all o-rings in the process including the water pump ones, new spark plug as well as cleaned up the piston and head. Fresh tank of gas. I go to start the bike, it starts first few kicks. But I heard an extremely loud rattle, first thought was it was the motor, but obviously I checked everything else to be sure, unfortunatly it is the motor. So I figured it was the timing off a tooth or something. Checked timing, it was fine. Started the bike again. Really rough to start and it couldn't idle now. Still had the rattle, but I have to rev the bike for it stay on. So I just killed the bike and it's currently sitting. 

 

Any thoughts?

IMG_0229.jpg

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Here's a video. You can see I can't start the bike without the throttle open and after I let it go, it sputters and dies out.

 

Youtube link because I can't upload a video directly.

 

 

 

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dumb question but did you mess with the idle when you had it apart?

 

If you want to run it up to MA we'll get you going.

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dumb question but did you mess with the idle when you had it apart?

 

If you want to run it up to MA we'll get you going.

 

I actually didn't touch the idle but did play with it to try and get the bike going. One thing I noticed is that my fuel screw (stupid R&D flex jet one) that was installed when I bought the bike is really hard to adjust. I went through the carb again last night and cleaned all jets and blew them out. Flex jet still wont spin.

 

My uncle used to be a motorcycle mechanic so I'm going to have him take a look at it, but I really appreciate your offer to help me out. I'll keep that in mind if he can't fix it.  

Oh and something I might add, the new spark plug I just put in already is turning black and I havent even gotten a chance to ride it, just starting it and running for a few seconds.

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I wouldnt worry too much about the plug being black if it is only starting and running poorly for a few min at a time.  once you get out and ride it make sure its not completely sooted up tho.  Since you have gone over everything mechanically and you say its all assembled correctly, I would look at the carb and make sure its adjusted properly as well. 

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Grabbed a set of feeler guages and checked the valves, the exhaust valves were both extremely tight. I'm assuming this is the problem but will have to wait until tonight when I get back from class to install the new shims. Shim kit is supposed to arrive today by the end of the day. I'll report back tonight after I adjust the valves. Hoping thats the problem because I've already gone through the carb.

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check you cam chain tensioner make sure its tightened and working properly .. note this from the manual -

This is a non-return type camshaft chain tensioner.
The push rod does not return to its original position
once it moves out to take up camshaft chain slack.
Observe all the rules listed below:
When removing the tensioner, do not take out the
mounting bolts only halfway. Retightening the
mounting bolts from this position could damage
the tensioner and the camshaft chain. Once the
bolts are loosened, the tensioner must be removed
and reset as described in “Camshaft Chain Ten-
sioner Installation”.
Do not turn over the crankshaft while the tensioner
is removed. This could upset the camshaft chain
timing and damage the valves.
 

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check you cam chain tensioner make sure its tightened and working properly .. note this from the manual -

This is a non-return type camshaft chain tensioner.

The push rod does not return to its original position

once it moves out to take up camshaft chain slack.

Observe all the rules listed below:

When removing the tensioner, do not take out the

mounting bolts only halfway. Retightening the

mounting bolts from this position could damage

the tensioner and the camshaft chain. Once the

bolts are loosened, the tensioner must be removed

and reset as described in “Camshaft Chain Ten-

sioner Installation”.

Do not turn over the crankshaft while the tensioner

is removed. This could upset the camshaft chain

timing and damage the valves.

 

 

Thanks, but I have a manual and have followed the steps for removing the tensioner so that is not the problem.

 

I won't be posting back for a few days until a new set of bolts come in for the camshaft holder and I can put the bike back together.

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Also, just need some quick advise. If I take the head back off, should I replace the gasket again? I literally just put a new one on and haven't even ridden the bike, only started it a few times for short periods of time.

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nope the gasket should be fine if it hasn't heat cycled, and even if it has it still probably fine.

Where you able to tell where the old gasket failed? make sure the head/cylinder sealing surface isn't warped?

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nope the gasket should be fine if it hasn't heat cycled, and even if it has it still probably fine.

Where you able to tell where the old gasket failed? make sure the head/cylinder sealing surface isn't warped?

 

Cool cool.

 

Yeah the old gasket was shot you see where there was coolant on the surface of the gasket where there definitely shouldn't be. Yeah I checked for warp.

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Getting new cam holder bolts, muffler packing, pilot jet and some oil filters on Thursday and the bike will be going back together. Will let you guys know how it goes. Had to adjust valves, the exhaust valve was so tight I couldn't fit any feeler gauges in between the cam and valve cap. Pretty sure that was the problem. Also I'm getting rid of the stupid R&D flex jet and putting in a stock pilot for now. Will buy a fuel screw at some point. I just want to get the back running and running well.

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Alright so here's an update. Put the bike back together, haven't put in the new pilot jet yet though. Start her up, ticking noise is still there. I think it's the cam chain at this point. Going to order one and install it. Hopefully will fix my problems.

 

However the bike wasn't consistent in it's running habits, one time I start it and it will stay running. The next it will die out. I think this has to do with the flex jet fuel screw being messed up but I will rule that out once I put the new jet in tomorrow.

 

Also it was fairly hard to start, is this a sign of the cam chain being bad?

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Another update. Just installed the new pilot air screw to replace the fuel screw. Set at 2 1/8 turns out as per manual. Bike starts after like 10 kicks but dies out once I take the choke off unless I'm on the throttle. Also I shot a few flames in the process of starting it.

 

Cam chain? Anything else? I really don't want to pay to have it looked it.

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Another update. Just installed the new pilot air screw to replace the fuel screw. Set at 2 1/8 turns out as per manual. Bike starts after like 10 kicks but dies out once I take the choke off unless I'm on the throttle. Also I shot a few flames in the process of starting it.

Cam chain? Anything else? I really don't want to pay to have it looked it.

Shooting flames? Black plug? It sounds a bit rich.

One thing to check is the throttle valve, it should be open a very tiny bit.. like 2.5 mm or so. Also if you haven't sorted the carb that needs to be the first priority.

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Also you should make sure your petcock is working properly.. your starting issue sounds like everytime I forget to turn the petcock open.

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