Jump to content

XR250L valve adjustment


Recommended Posts

Have a 96 XR250L and trying to adjust the valves for the first time !

The exhaust valves seem way too tight - I would have thought they would have loosened up after 5000 miles. The intake valves are too hard to get to. I just can't seem to get in there and check - looks like even with the tank off, the frame would block good access to the intakes. Any comments or tips here -

Link to comment
Share on other sites

chiefculprit is right, it really is much easier than it looks. i have the guages that are all flat with no bends in them and the are so thin they slide in really easy.

here is how i do it.

move it to TDC, make sure it is the right TDC.

move your shoplight so you can see what is going on.

loosen the 10mm nut on the post.

spin the adjustment up a little bit up.

slide the feeler underneath in the gap. it is easy.

while sliding the feeler back and forth turn the post down with fingers until it grabs the feeler guage. This lets you know you have the feeler in the right place etc.

with the screwdriver turn the post until the guage slides with drag.

let go of guage, grab wrench cinch the bolt down while holding the post with your screwdriver.

recheck the gap with the guage.

recheck the nut is tight.

recheck the gap with the guage.

after you have done all four sorta rattle each one and make sure it feels like its matching rocker.

bike will run allot better with valves adjusted correct.

Good luck.

markyuma

Link to comment
Share on other sites

Here is a previous post on valve adjustment:

https://thumpertalk.com/forum/showthread.php?t=902580&highlight=.

http://en.wikipedia.org/wiki/Four-stroke_engine

I was sketchy about doing the valves but made myself learn it. Take the tapet covers off and turn the fly wheel and watch the valves move. Also what helped me was to remove the spark plug and put a long straw into the hole and watch it go up and down. On the compression stroke (piston going up) you will notice the rockers flatten out, that is the TDC you are looking for and verify with the mark on the case and flywheel. Also you should be able to rattle all 4 rockers with your fingers (very little play but its there) telling you correct TDC. Good luck tons of people here can help with just about anything you want to do to your bike.

Link to comment
Share on other sites

The exhaust valves seem way too tight - The intake valves are too hard to get to. I just can't seem to get in there and check - looks like even with the tank off, the frame would block good access to the intakes.

you mean tight for the nut or the valve clearance? if is clearance what you mean you may want to be careful here since the T (TDC) at the rotor could be the compression stroke (which is what we need) or the exhaust which gives a bit clearance at the intake but makes the exhaust ones tight (since they're open) so what we need is TDC compression so there should be a bit of play in both intake and exhaust valves, but I am just assuming you meant tight clearances

Link to comment
Share on other sites

Thanks for all the help here - When I checked the exhaust valve clearance, it seemed too tight. I was afraid to make any adjustment. I lined up the TDC mark - could this be 180 degrees off and need to go around again or is it always at TDC when the marks are lined up?

Link to comment
Share on other sites

You have 2 TDC and 2 BDC (4 strokes) Stroke 1 is fuel intake (piston goes down) Stroke 2 is compression to ignite (piston comes up) Stroke 3 ignition explosion (piston goes down) Stroke 4 exhaust elimination (piston comes up). As basic as I know it. Like I said before: "Take the tapet covers off and turn the fly wheel and watch the valves (sorry - rockers) move. Also what helped me was to remove the spark plug and put a long straw into the hole and watch it go up and down. On the compression stroke (piston going up) you will notice the rockers flatten out, that is the TDC you are looking for and verify with the mark on the case and flywheel."

Link to comment
Share on other sites

Took the seat and tank off - first time they have ever been off !! With the tank off, there is good access to the valves so I'm going to do the adjustment tomorrow. Thanks for all the help here.

Link to comment
Share on other sites

Did the adjustment this morning - easy with the tank off. Exhaust valves loose by .001, intake loose by .001. Just took a test ride and no noticeable improvement but I'm glad I did the adjustment. When I had the seat off I drilled some holes in the air box snorkel on top - thought that would allow it to breath better.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

×
×
  • Create New...