valve adjustments clarified for the XR600R ... you can do it! here's some tips.

[woodbutcher80]

ok guys .

so i recently bought a 93 xr600 . rode an xr when i was a youngin and now wanted to buy my own big red pig.

anyways , i did everything to the T like the manual said ...

i got the dash next to the T mark lined up , and like many people who posted on TT , i had to use a small bungee on the kick starter to keep pressure on the flywheel to keep the mark lined up perfect.

i realized the valved were wayyy too tight , so i loosened them up , and got the feeler gauges to just lightly rub .

i then put her back together and started her up ...

CLACK CLACK CLACK !!!!

thats all i heard . and JUST like many people on here, it was louder than before the adjustment! and no , clacking valves are not happy valves . think sewing machine....

well i couldnt figure it out until i read between the lines in the manual ..

it said to set the TDC on the compression stroke . well , this little video helped me out on that : http://www.youtube.com/watch?v=RbrVR6Tm8Vk

keep an eye on the upper left intake valve in the video ... when you see the INTAKE rocker move , the piston is on the downstroke and the intake valve is letting in a mixture of air and gas.

the piston then begins to rise up on the compression stroke the manual is talking about . THIS is where you need to be in regards to the T mark on the flywheel . if you see the T mark but you notice that if you pass the T mark by a smidge and the intake rocker is moving, you need to rotate the flywheel counter-clockwise one more time to get to the compression TDC. in other words, you have a 50% chance of getting it right the first time you line up the T mark...just be sure,

now... im sure your thoroughly confused right now .. and if you are, no worries. to makes matters simpler, try this explanation:

take out the inspection hole allen key , and dont worry about the big allen key crankshaft cap below the inspection hole in the center. when the crankshaft cap is off,the manual says to turn the flywheel with a socket to rotate it counter clockwise...

i got an easier way : put the pig in 4th or 5th gear, put her on a stand and just rotate the rear wheel forward(the direction you ride it) to line up the marks. the wheel seems to hold it in place well(no bungee needed) .

ANYWAYS , when your rotating the flywheel , watch the intake valves(the two closer to the rear of the bike) . when you see them move and then stop , keep a close eye in the inspection hole... the NEXT TIME YOU SEE THE MARK NEXT TO THE T ,STOP ! your good to go . all valves rockers should be loose , including the front right exhaust valve which is connected with the decomp lever(everyone has an issue with this).

i got around this lever by making it completely loose with the adjusting nuts on the cable. i left it loose until i was done adjusting the valve clearance on that front right valve. then i simply adjusted the compression cable nuts so that the metal rod thing that hits the rocker was about 1/8" away from touching it . you can verify the distance after your totally done with the valve job by pulling on the manual decompression lever on the handlebar . i like to have to pull my lever half way before the metal rod hits the rocker arm/valve assembly to relieve pressure.

in regards to the valve clearance of .004 on intake and .005 on exhaust... the best way to explain it is you should be able to slide the feeler gauge in there and it should have decent resistance.. good enough that if you put in one size bigger feeler, it wouldnt go in unless you held it real tight and jammed it in .

well thats how i did it at least .

you SHOULDNT hear really any clacking at all when done .

the BEST way to describe the sound is a sewing machine whistling . . or if your around street bikes like a honda inline 4 it should sound like that when your ear is by the engine.

ihope this helps clear up some of the other posts. i know i understood most of them except i just bypassed the compression stroke part of the directions since only a couple of the tutorials said to do that . most said to just line up the T mark .

just be sure to line up the T mark AFTER the intake valves make their move.

look at that link above again... look at when the video is at 4 seconds. this is where you need to be when at true TDC . youll notice the intake valves do their move just before this true TDC.

just my 2 nickels on it .

now get clacking!

Edited December 28, 2010 by woodbutcher80

[natey]

+1 ........I just set my valves for the first time at 13,000 miles. What a mistake to not check them many moons ago. The intakes, which are supposed to be at .004, were at .007 and .006. The exhaust were a tight .005.

I turned the crank to top dead center several times to get it to land on the mark, then read that taking the plug out was a good idea to even out the turning making it easier to hit the mark, and to make sure it's the right color and is not worn in terms of a rounded electrode. At the correct top dead center, you will be able to feel free play in all valves by grasping and moving up and down.

The thing to keep in mind is that you can force a .006 into the valve adjuster, but it won't go in easily. So if you want to make sure you are right, you can see how the next size slides in and thus determine if you are each them accurately. Playing with different sizes allows you to contrast right and wrong so you can make sure you are accurate.

Anyway, the end product is like woodbutcher said, sewing machine sounding, smooth and quiet. Wow what a difference, and you can be assured that i will be checking these more often to see if they change that much on their own and how long it takes.

This is definitely easy to do but just requires a little practice to make sure your accurate. And don't be a dumb-ass like me and avoid this.

[woodbutcher80]

sorry , the old youtube link has been closed ... this one will help if anyone needs it . intake valve is on the right side in this one though .

[bork]

Remember, better loose than too tight. Too tight will result in leakage, after the heat swelling takes up the slack, & thus, burning seat mating surface.

[Little Fauss]

ok guys .

so i recently bought a 93 xr600 . rode an xr when i was a youngin and now wanted to buy my own big red pig.

anyways , i did everything to the T like the manual said ...

i got the dash next to the T mark lined up , and like many people who posted on TT , i had to use a small bungee on the kick starter to keep pressure on the flywheel to keep the mark lined up perfect.

i realized the valved were wayyy too tight , so i loosened them up , and got the feeler gauges to just lightly rub .

i then put her back together and started her up ...

CLACK CLACK CLACK !!!!

thats all i heard . and JUST like many people on here, it was louder than before the adjustment! and no , clacking valves are not happy valves . think sewing machine....

well i couldnt figure it out until i read between the lines in the manual ..

it said to set the TDC on the compression stroke . well , this little video helped me out on that : http://www.youtube.com/watch?v=RbrVR6Tm8Vk

keep an eye on the upper left intake valve in the video ... when you see the INTAKE rocker move , the piston is on the downstroke and the intake valve is letting in a mixture of air and gas.

the piston then begins to rise up on the compression stroke the manual is talking about . THIS is where you need to be in regards to the T mark on the flywheel . if you see the T mark but you notice that if you pass the T mark by a smidge and the intake rocker is moving, you need to rotate the flywheel counter-clockwise one more time to get to the compression TDC. in other words, you have a 50% chance of getting it right the first time you line up the T mark...just be sure,

now... im sure your thoroughly confused right now .. and if you are, no worries. to makes matters simpler, try this explanation:

take out the inspection hole allen key , and dont worry about the big allen key crankshaft cap below the inspection hole in the center. when the crankshaft cap is off,the manual says to turn the flywheel with a socket to rotate it counter clockwise...

i got an easier way : put the pig in 4th or 5th gear, put her on a stand and just rotate the rear wheel forward(the direction you ride it) to line up the marks. the wheel seems to hold it in place well(no bungee needed) .

ANYWAYS , when your rotating the flywheel , watch the intake valves(the two closer to the rear of the bike) . when you see them move and then stop , keep a close eye in the inspection hole... the NEXT TIME YOU SEE THE MARK NEXT TO THE T ,STOP ! your good to go . all valves rockers should be loose , including the front right exhaust valve which is connected with the decomp lever(everyone has an issue with this).

i got around this lever by making it completely loose with the adjusting nuts on the cable. i left it loose until i was done adjusting the valve clearance on that front right valve. then i simply adjusted the compression cable nuts so that the metal rod thing that hits the rocker was about 1/8" away from touching it . you can verify the distance after your totally done with the valve job by pulling on the manual decompression lever on the handlebar . i like to have to pull my lever half way before the metal rod hits the rocker arm/valve assembly to relieve pressure.

in regards to the valve clearance of .004 on intake and .005 on exhaust... the best way to explain it is you should be able to slide the feeler gauge in there and it should have decent resistance.. good enough that if you put in one size bigger feeler, it wouldnt go in unless you held it real tight and jammed it in .

well thats how i did it at least .

you SHOULDNT hear really any clacking at all when done .

the BEST way to describe the sound is a sewing machine whistling . . or if your around street bikes like a honda inline 4 it should sound like that when your ear is by the engine.

ihope this helps clear up some of the other posts. i know i understood most of them except i just bypassed the compression stroke part of the directions since only a couple of the tutorials said to do that . most said to just line up the T mark .

just be sure to line up the T mark AFTER the intake valves make their move.

look at that link above again... look at when the video is at 4 seconds. this is where you need to be when at true TDC . youll notice the intake valves do their move just before this true TDC.

just my 2 nickels on it .

now get clacking!

?

Reading your post yesterday got me busy clacking last night. I had "done" my valves but it didn't seem right (clacking). Checked last night, all were set loose, probably had it on wrong stroke. This morning, started easy and quiet and I lost the blue smoke startup. Thanks:banana:

[woodbutcher80]

no problem ...

[Kenzo]

...u want easy?

...u want foolproof?

forget top dead center compression stroke!

with the bike on a stand...transmission in top gear...turn the rear tire/wheel forward and observe the valvetrain...

...always adjust closed intake valves when exhaust valves are opening(~1/2 way).

...always adjust closed exhaust valves when the intake valves are closing(~1/2 way).

to make it a one man job i use a BF-screwdriver or prybar between the spokes and the swingarm to keep the valvetrain in place against the force of the valve springs...it will want to rotate past that point...but DO NOT rotate it backwards to position the valvetrain correctly or else u'll engage the decomp/anti-kickback on the XR engines.

this method works on virtually all dirt bikes w/ 4 stroke motors...

...even the L!

?

[Justinsaneok]

...u want easy?

...u want foolproof?

forget top dead center compression stroke!

with the bike on a stand...transmission in top gear...turn the rear tire/wheel forward and observe the valvetrain...

...always adjust closed intake valves when exhaust valves are opening(~1/2 way).

...always adjust closed exhaust valves when the intake valves are closing(~1/2 way).

to make it a one man job i use a BF-screwdriver or prybar between the spokes and the swingarm to keep the valvetrain in place against the force of the valve springs...it will want to rotate past that point...but DO NOT rotate it backwards to position the valvetrain correctly or else u'll engage the decomp/anti-kickback on the XR engines.

this method works on virtually all dirt bikes w/ 4 stroke motors...

...even the L!

?

= 1000 the only way to do it on a harley.

[elsalvadorXR6]

I have a dumb question.

what if you dont have a kickback or automatic decomp on your cam? does rotating back still have the same negative effects?

stupid I know, but Im about to do my valves at 350miles after rebuild.

cheers

[woodbutcher80]

I have a manual decomp too . It isn't hard at all to keep it from rolling back if its in a high gear while rotating the wheel . Just follow my op, check the valves and you'll be good to go

[Justinsaneok]

I have a manual decomp too . It isn't hard at all to keep it from rolling back if its in a high gear while rotating the wheel . Just follow my op, check the valves and you'll be good to go

Ya its never a good idea roll a 4 stroke backwards. I had a kdx 200 backfire when trying to start because the plug was shot and it started backwards. I didn't know and dumped the clutch and got 30 feet before managing to pull in the clutch. Somehow I didnt crash. Most the time if a 4 stroke turns backwards things break.

[Kenzo]

I have a dumb question.

what if you dont have a kickback or automatic decomp on your cam? does rotating back still have the same negative effects?

stupid I know, but Im about to do my valves at 350miles after rebuild.

cheers

most bikes it's not a problem to counter rotate the motor a few degrees to get on the heal of the cam...

...the XR's with it's decomp/anti-kickback design is the only one that i'm aware of that there is a problem...

...it will automatically open the right exhaust valve(if i remember correctly) giving u and incorrect lash/gap reading.

?

[elsalvadorXR6]

thanks...

I just wanted to know if by disabling the "problem" i.e. automatic decomp negates valve setting issues like roll back...

In other words since there is nothing to cause problems when adjusting the valves is there an issue if you "happen" to roll the crank back and forth looking for TDC?

thanks for your post, its great and informative as well as easy for the newb, we all learn something...

christian

[elsalvadorXR6]

thanks KENZO

I specifically took off my auto decomp on the cam and welded it shut to make my valve adjust easier, I see no purpose for it too since it fails high mileage wise, makes noise and makes finding tdc for valve adjust harder.

sooo......

if there is nothing to cause problems should I be as carefull with ROLL BACK or not

also what would break when a piston and vakve train rotates backwards? I dont get it

I did this during the rebuild and I fail to see what happens that would break stuff

thanks

I am looking for wisdom here....

sorry for hijack

christian

[elsalvadorXR6]

well I just did mine, took the plug out and loosened all the adjusters first so I could make sure I was at tdc easily,

mine were slightly tight after about 500 miles rebuild, so who knows?

all I know is that they are looser and set well now and the bike has more snap off idle...

thanks OP...

sometimes one forgets how to do stuff,,,,

cheers