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195exh shims seem to be down in a hole? bad parts?

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I pulled the valve cover on an 07 crf250r to find the 195 exhaust shims low in the retainers both sides. the shims do not stand proud of the retainers at all  and getting a tapered feeler gauge in results in a dished or concave shape between the shoulders of the retainers.

I am thinking hard about this, 

the tips of the valve stems look fine no mushrooming no damage. could the keepers be wearing out?

is it possible a machinist trimmed the tips off the ex valves back when kw intakes were done?

could the keeper groves in the valve stems be wearing out?

could the retainers be wearing out?

could someone have installed intake keepers on exhaust valves at some point?

I looked at an other 250's head and see the shims stand tall above the retainer .

when I measure from the shoulders of the retainer to the valve tips I get 1.5mm what do you guys get?

I have shimmed a few heads in my day and have not seen this on other crf 250/450 bikes and I am wondering what to do here so any help appreciated thanks.

 

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checking the parts pic I see #13  #21 for int and ex retainers is their a chance these parts would sit on the opposite valve springs?

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The 07 parts diagram shows the same part # for the intake and exhaust retainers, but in 08 the intake side stayed the same but the exhaust valve stem size was reduced by half a MM. Because of that the exhaust retainers were different and cotters also, so there may be a parts mix up or like you were saying possibly the KW valves are the issue.

If KW valves are whats being used you need to use the KW retainers, springs and spring bases also.

Are the valves new? Did it have the correct valve clearance at one time but now doesnt?

Anyway good thing you caught it before a major engine problem occurred.

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tdw its a friends bike it had the kibble white intake put in a year ago and the ex valves remained unchanged, the guy shimed the valves and it developed a tick at that time. I pulled it apart and found a bad pin bore in the piston, then putting it back together I come across this ex valve shim deal so I think it over and ask questions.

I looked at the rockeymountainatv Honda parts pic-  noticed numbers 13 and 21 for int and exh retainers but I better compare part numbers I guess.

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I had an 08 that had the same issue on a brand new OEM head with all new OEM valves & hardware. i ran shims that made it flush with the retainer and that had me .001 tighter than the min spec. The correct shims had the shim recessed below the retainer like you.

Never got to the bottom of it, just ran it slightly tight without issues. Luckily exhaust valves dont normally move. I triple checked all the part numbers and they were all correct.

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A 1.95 mm or .076" shim is a little thinner than most of the shims Ive seen on the exhaust side, and is a more common size on the intake side in general.

I think nzgsr makes a good point about trying a thicker shim and re checking the clearance. Is it possible the shim is to thin and the clearance reading being taken is between the retainer and rocker arm, instead of between the shim and the rocker arm?

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for sure the 195 shims are down deep in the hole and the  feeler goes in at a bad angle- its just wrong.  bigger shims will get it above the retainers and give a true reading.

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I had the same problem when I sent my head out for it to be check out. Was told the seats needed re cutting so went along with it. When it came back, I checked the clearances once it was back on the bike

and t it was like what you describe

ImageUploadedByThumper Talk1457384304.900146.jpg

ImageUploadedByThumper Talk1457384335.457050.jpg

I ended up sending it out somewhere else and I had new valves put in

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Hello everyone

I have an 08 with the same problem in a brand new OEM head with all new proxy valves and oem springs, gaskets,seals.is it normal?I could not find the problem

inde22x.thumb.jpg.4d3c2f5c281c02bc70d190429cb8f66a.jpgcheck 0,32index.jpg.9cfc0417e9a587a445f94854289f33f4.jpg0.20mm

 

which one is right?

 

in3333dex.jpg

Edited by Miral Atli

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On 10/18/2020 at 1:19 AM, Miral Atli said:

Hello everyone

I have an 08 with the same problem in a brand new OEM head with all new proxy valves and oem springs, gaskets,seals.is it normal?I could not find the problem

inde22x.thumb.jpg.4d3c2f5c281c02bc70d190429cb8f66a.jpgcheck 0,32index.jpg.9cfc0417e9a587a445f94854289f33f4.jpg0.20mm

 

which one is right?

 

in3333dex.jpg

Not real sure what your question is, or what problem your having with this. Did you get it all figured out? 

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