WR250F '02

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L.B
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WR250F '02

#1 Post by L.B » Tue Jun 05, 2012 12:24 am

Hi,
Really didnt know where else to put this,was even worried about posting about it in the first place!
Do a re-shim on a mates bike,WR250F.Anyone here done one already?
I've np's actually doing it,but just after any pointers I should know about before I dive in.....

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aaronmvrider
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#2 Post by aaronmvrider » Tue Jun 05, 2012 12:59 am

they have valves... not powervalves.... :smt006 :smt006


oooh the shame of it .... :smt019 :smt019
1 x 4mm stroker rz 375cc 1983
1 x 7mm stroker rz 443cc 1984 (under construction)
1 x rz 500
1 x mv agusta 1000

cbirk
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Re: WR250F '02

#3 Post by cbirk » Tue Jun 05, 2012 10:07 am

L.B wrote:Hi,
Really didnt know where else to put this,was even worried about posting about it in the first place!
Do a re-shim on a mates bike,WR250F.Anyone here done one already?
I've np's actually doing it,but just after any pointers I should know about before I dive in.....
Measure once with the feeler guage and then swap the shim. DON'T replace the shim more than once. Meaning, if you measure your lash, measure your existing shim, and then figure the difference and put in the correct shim. After that you're good. DON'T REMEASURE AND THEN RESHIM!! If do right you won't make a mistake. Sometimes the shim gets stuck in the retainer and the strongest magnet won't pull it out. In that case, just push down on the spring retainer and the top of the valve will pop it out during compression. Oh, and if the service intervals are the same as our YZf's, replace the timing chain while you're in there. They are cheap and recommended to change every 8 hours or so. Oh, and don't over-torque the cam retainers. They are only 8mm bolts. If they are over torqued you will cause premature wear on the cam journals.

Born and raised on thumper 4strokes. Done valves on my Husky Supermoto, YZ250f, KX250f, buddies YZ450f/yz250f, and many more. lol (the RZ is my first 2T which is why I suck at it)


:smt006
1982 CB750f SS
2005 CRF50
2006 YZ 144

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L.B
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#4 Post by L.B » Tue Jun 05, 2012 11:00 am

Gotcha there & understand why!
Problem,drained oil pulled the filter & found a ton of metal filings in filter housing,so I be bolting it back together & leaving this lil time bomb.
Yes Aaron,Im bi - mechanical :smt005

cbirk
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#5 Post by cbirk » Wed Jun 06, 2012 11:25 am

L.B wrote:Gotcha there & understand why!
Problem,drained oil pulled the filter & found a ton of metal filings in filter housing,so I be bolting it back together & leaving this lil time bomb.
Yes Aaron,Im bi - mechanical :smt005
Metal shavings are normal in the screens believe it or not. That why they are there. Lol Every thumper I've owned or worked on has had them. My buddy broke in his 2011 kx450f the other week and pulled shavings out at 3 hours. lol Now if they were chunks I would worry. How many miles are on the bike? I would at least check the valves.
1982 CB750f SS
2005 CRF50
2006 YZ 144

jord-rz
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Re: WR250F '02

#6 Post by jord-rz » Wed Jun 06, 2012 2:57 pm

[/quote]

Measure once with the feeler guage and then swap the shim. DON'T replace the shim more than once. Meaning, if you measure your lash, measure your existing shim, and then figure the difference and put in the correct shim. After that you're good. DON'T REMEASURE AND THEN RESHIM!! If do right you won't make a mistake. [/quote]

Why wouldnt you recheck your valve clearance after you installed the new shim? obviously you would do it right if you didnt make a mistake, but how are you gonna know if you made a mistake if you dont check your work?
85' rz350 - R6 rear shock, progessive springs & race tech emulator, Fork brace, steering damper, 01' r1 front brakes, GPL Racing ported cylinders & milled head, GPL Racing gp exhaust, V-force reeds, reed spacers, 28mm PWK'S, Zeeltronic pcdi -10v

cbirk
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Re: WR250F '02

#7 Post by cbirk » Wed Jun 06, 2012 3:47 pm

jord-rz wrote:
cbirk wrote:
Measure once with the feeler guage and then swap the shim. DON'T replace the shim more than once. Meaning, if you measure your lash, measure your existing shim, and then figure the difference and put in the correct shim. After that you're good. DON'T REMEASURE AND THEN RESHIM!! If do right you won't make a mistake.
Why wouldnt you recheck your valve clearance after you installed the new shim? obviously you would do it right if you didnt make a mistake, but how are you gonna know if you made a mistake if you dont check your work?
The shim needs a heat cycle to properly seat itself back in to the retainer. If you keep pulling the shim in and out to check and recheck you will end up with inconsistent and wrong measurements and ultimately the wrong shim.

If you really want to recheck, then do it after you heat cycle the engine, wait for it to be completely cool and then recheck. I think the Yamaha service manual has a chart that will tell you exactly what shim to put in based off your lash and existing shim. Now the one thing I've always found to be a bit ambiguous was the correct "feel" of the feeler gauge. What I think to be a light drag may be loose to someone else. idk...

I have a complete Hotcams shim kit for your WR (7.48mm) if you need it L.B.
1982 CB750f SS
2005 CRF50
2006 YZ 144

jord-rz
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#8 Post by jord-rz » Wed Jun 06, 2012 5:06 pm

where did you learn that? From all the school and training, countless service manuals ive seen and opinions from other technicians, Ive never ever heard of that. I dont believe that you would need to do a heat cycle to have it seat properly, its not like its a press fit or something like that. The shim would not change size once its cooled. When doing on a valve adj on something like a modern 600 or 1000, it can take quite a long time. I dont think it would smart to have to tear everything apart after a heat cycle just to make sure the valves were adj properly.
85' rz350 - R6 rear shock, progessive springs & race tech emulator, Fork brace, steering damper, 01' r1 front brakes, GPL Racing ported cylinders & milled head, GPL Racing gp exhaust, V-force reeds, reed spacers, 28mm PWK'S, Zeeltronic pcdi -10v

cbirk
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#9 Post by cbirk » Wed Jun 06, 2012 5:42 pm

jord-rz wrote:where did you learn that? From all the school and training, countless service manuals ive seen and opinions from other technicians, Ive never ever heard of that. I dont believe that you would need to do a heat cycle to have it seat properly, its not like its a press fit or something like that. The shim would not change size once its cooled. When doing on a valve adj on something like a modern 600 or 1000, it can take quite a long time. I dont think it would smart to have to tear everything apart after a heat cycle just to make sure the valves were adj properly.
I learned that from experience and then was reassured the technique from one of Grant Langstons mechanics who then became a mechanic for Aussie Dave Road Racing, and also from my buddy who is an emission engineer for S&S. On a thumper it's no big deal to run the bike, cool, and then recheck. (except for the amount of time it wastes) I could see for an I-4 it being a p.i.t.a. I suppose you could simply turn the engine multiple times to get the shim to seat properly. By me saying "heat cycle" I should have clarified it a little better as heat is not needed for anything. It was laymen's term for spin the engine a shit load knowing it would be sufficient. From what I remember, service manuals are of a measure twice cut once mentality and don't have you recheck.. I could be wrong though and unfortunately I don't have 4t thumper anymore to have the ability to check the manual. I guess everyone wrenches differently.
1982 CB750f SS
2005 CRF50
2006 YZ 144

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L.B
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#10 Post by L.B » Fri Jun 15, 2012 9:21 am

Guys need some input,Ive gone & shimed the valves,all intakes are bottomed out,<.04 or 1 thou!Exhaust is way down too.
If intakes have bottomed out & low compression,does this mean valve seats could be totalled?

jord-rz
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#11 Post by jord-rz » Fri Jun 15, 2012 10:52 am

not necessarily, what did you get for a compression test. Remember that with tight valves, the valves are open longer. So it will give you a lower compression reading than if the valves were at spec. how many kms on the bike? I wouldnt worry too much about worn valve seats, usually its the valve that wears. Just shim it to the proper spec and hold er
85' rz350 - R6 rear shock, progessive springs & race tech emulator, Fork brace, steering damper, 01' r1 front brakes, GPL Racing ported cylinders & milled head, GPL Racing gp exhaust, V-force reeds, reed spacers, 28mm PWK'S, Zeeltronic pcdi -10v

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L.B
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#12 Post by L.B » Fri Jun 15, 2012 11:00 am

Thanks jord,unfortunately I haven't done comp test yet.But can kick it over with one hand easy,without decomp lever!Its an 02 model,hard life from the looks,dont know how many km's been disconnected.It is not running either....
What I meant was it couldnt be good if intake factory spec's state .10 to .15mm,I cant even get a .04 shim between the cam/valve...
Plus the metal in the oil was a real worry,I mean there was alot!
Should I just pull the cams & do the shims & see what happens?

jord-rz
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#13 Post by jord-rz » Fri Jun 15, 2012 12:25 pm

ya, pull the cams, check for wear on the cam journals and shafts. Put the new shims in and run it. thats all u really can do, unless you wanna spend a bunch of time trying to find where the shavings came from. What did the shavings look like? there they magnetic? Steel shavings arent a huge deal (depending on how much) as long as u didnt get chunks, or teeth lol! also if the oil came out kind of gray thats not good, means the aluminum has worn. If I were you I would put the valves to spec, try and get a proper compression test done and run it up and see how she sounds. do you have a manual? Let me know if you need specs, I can bring up the service manual off the yamaha dealer site.
85' rz350 - R6 rear shock, progessive springs & race tech emulator, Fork brace, steering damper, 01' r1 front brakes, GPL Racing ported cylinders & milled head, GPL Racing gp exhaust, V-force reeds, reed spacers, 28mm PWK'S, Zeeltronic pcdi -10v

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L.B
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#14 Post by L.B » Sat Jun 16, 2012 2:09 am

Rightio then,thanks again Jord,I have the fac spec's.Ill rip into it & see what happens.Oil was clean,looks more like hard facing,why I suspect the valve stems could be toast.
Only thing I gotta get my head around the shim sizes lol....Ill pull them out an order a set.

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L.B
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#15 Post by L.B » Tue Jul 31, 2012 9:02 pm

First up,big thank you to cbirk for shim kits. Hope you're healing up fast mate.
Just like to check with you guys.
Inlet clearances on this bike are ·15mm. Now before i pulled the bike apart inlet valve clearance was zero. The shims that i pulled from bike are 1.9mm. Now i subtract ·15 from 1.9 =1.75 sized shim.
Is this correct way of working out clearances (not my numerical skills lol)

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