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02 XR250 Valve measuring

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I've run into a problem ad am confused. Manual says to line up the T on the compression stroke and measure valve clearances. I did. However, I noticed quite alot of ticking upon reassembly. I disassembled, remeasured and the RH exhaust continued to click. More didling around unveiled a substantial gap (like as thick as a nickel in that same exhaust valve after more rotation of the lywheel and the pressure was off that valve. What i noticed was that there are three markings on the flywheel. First a II then the F then the T. For kicks I called TDC the place where the II mark aligned with the mark on the case. Remeasured / adjusted / reasssembled and the thing purrs like a kitten. I disassembled again, aligned this time as per the manual with the T , reassembled and the clicking was back as was the major RH exhaust valve gap. Now I'm really confused. Anybody help me with this? 

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The automatic decompression lever is activating. Rotate the motor just past TDC and then back clockwise to TDC and you can hear a slight click as the decomp releases. Then you adjust the right side.

Put a big wrench  on the crank and roll the motor around a few times and it will all make sense

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Hmm, its a manual decomp? You sure?

Also, this is maddening as this isn't this mentioned in the manual? My lever is set so that tis backed out all the way on the adjustment setting. 

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I'm having a similar issue with my XR250L 1991. I can't get the thing to stop ticking. I have an automatic decomp, and I can't figure out how to get the spark plug out. I have a number of long sockets from 10mm to 19mm but none of them seem to fit in the gap to get the spark plug out. I made sure to make the decomp as loose as possible.

 

I've measured my valve clearance 3 times, making sure to follow what my manual said: Rotate the crank counter-clockwise until the T line lines up with the notch on the crank case bolt hole thing. My Haynes manual said specifically make sure NOT TO ROTATE clockwise at all. It also said to make sure that I am on the compression stroke TDC, not the exhaust stroke TDC. It said if I'm on the exhaust stroke TDC the valves will have no free play in them at all but when it's on the compression stroke they will...so I made sure I was doing that right too. But I still have REALLY bad ticking and I can't freakin figure it out.

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Well i had repeated the measuring, assembly, check, disassembly, etc so many times I bit the bullet and dropped it off at my local shop. :(

It was beyond frustrating. Even my POS Crf250x wasn't this weird.

Whats more, I bet its something simple. I have trouble shot this enough and am losing riding time.

I'll let you know what the issue was as rest assured, bringing my bike in and paying someone to fix it is a huge dent in my mechanical pride.

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Well turns out 4strokeridertt is correct. It only cost me 50 bucks for verification but I think I'm gonna send the bill to Honda . The the exhaust is measured as 4stroke says..,, the problem is..., the f****** manual seems to omit this point.

I'm pissed but now the beast purrs like a kitten

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Yofrankie

Can you explain a little better what was happening and how it was fixed? Like I said I'm trying to figure out why mine is ticking too.

My manual said to line up the T line and to specifically NOT rotate the crank clockwise...

The guy you said was right was saying to rotate it past the T then back a bit to the T to release the decomp....but you said you don't have an automatic decomp??

Mine is a XR250L with an automatic decomp cable running to the kickstart. I do not have a manual decomp lever on my bike.

Edited by TonesMagones

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It's possible that the flywheel has somehow rotated on the crank, placing the T mark in an arbitrary location.  This could be caused by a backfire which has sheared the key allowing the flywheel to rotate or the flywheel could have been installed without the key.  You can confirm the T mark by using a piece of wire to feel TDC through the spark plug hole.  This method is also accurate for installing the cam and aligning the timing marks on the gear.  I don't like crawling around on my hands and knees to look for the T mark, so this is my standard procedure for valve adjustment as well as cam timing.  A rotated flywheel presents no problem if you use this method.  The spark plug can be removed with a thin-walled 18mm deep socket, and some riders have used a grinder to make them fit, but the oem spark plug wrench that comes in the tool kit is much easier to use, especially on the 400.

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You can confirm the T mark by using a piece of wire to feel TDC through the spark plug hole.

Ok so you're saying take a piece of wire, hold it through the spark plug hole and rotate the crank with the wrench to find the highest TDC point.... Basically the wire will be moving up as I'm turning, then at some point it will be moving back down so in between those points is the point of TDC?

Should I be rotating counter clockwise the entire time? People have been saying go past the TDC point then go back clockwise to release the automatic decomp.... But my manual says NEVER rotate clockwise because that will activate the auto decomp....

Is there a way to tell whether its activating or not? For example when I push the kick start I can see it activating.... But I can't recall if it does the same thing when I rotate the crank manually....

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I HAVE THE SAME BIKE, SAME YEAR AND HAVE NOT HAD THIS PROBLEM.

 

Ok so you're saying take a piece of wire, hold it through the spark plug hole and rotate the crank with the wrench to find the highest TDC point.... Basically the wire will be moving up as I'm turning, then at some point it will be moving back down so in between those points is the point of TDC?

 

CORRECT

Should I be rotating counter clockwise the entire time? People have been saying go past the TDC point then go back clockwise to release the automatic decomp.... But my manual says NEVER rotate clockwise because that will activate the auto decomp....

 

ROLLING IT BACK SLIGHTLY WON'T HURT IT IF YOU KEEP IT TO A MINIMUM.

Is there a way to tell whether its activating or not? For example when I push the kick start I can see it activating.... But I can't recall if it does the same thing when I rotate the crank manually....

 

YOU COULD JUST DISCONNECT THE CABLE TEMPORARILY.  YES, YOU CAN SEE THE LEVER ON THE HEAD MOVE.  YOUR CABLE MAY BE ADJUSTED TOO TIGHT.

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Be sure to rotate the crank in the recommended direction. CW or CCW, documented here. Use search.

If you think the manual compression release is causing problems, disconnect the cable. Plenty of slack now.

When adjusting the valves at the T mark, the piston is at full compression and the rockers should be loose, so all 4 wiggle.

The hard part is the piston will want to rotate beyond TDC.

Either remove the spark plug or use a heavy wrench. I use my old torque wrench that does not wratchet and is heavy.

The motion pro feeler guages are great for setting the valves. Worth the cost.

http://www.motionpro.com/motorcycle/partno/08-0393/

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