Yz250f valve question

kb22
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kb22
Edited Date/Time 1/13/2021 6:23pm
Hello all I was hoping you all could help me out with a valve clearance check. So I would call myself a fairly mechanicaly inclined person but a bit ocd. So when I am checking the clearance are we aiming for the feeler to slide all the way through? Or is it suppose to slid just to the middle of the lobe? With the buckets it’s a bit different than I am used to. I appreciate any help or guidance, thank you in advance.

Keith
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kb22
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kb22 1/8/2021 7:25pm
1/8/2021 7:25pm
Ahhh that means they are way off then, thank you very much for the clarification. Is it typical that the exhaust valves could be measuring like .06-.08 instead of the .18-.24?
Paul_Pitzonka
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Paul_Pitzonka 1/8/2021 7:37pm
1/8/2021 7:37pm Edited Date/Time 1/8/2021 7:44pm
Yes, valves tend to tighten over time as the seat and valve wear... On many of the bikes I’ve seen the intake valves tend to lose clearance faster than the exhaust, but this is more than likely caused by poor air filter maintenance...
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kb22
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kb22 1/9/2021 2:51am
1/9/2021 2:51am
Well I’ve done the oil every ride and air filter every ride so I guess the guy before had lack luster maintenance. I’ll re-check tonight after work but idk how much more tdc I can get. Recommendations on going with a re-cut over a shim? I have been eyeballing Williams motorworks. Thanks again for the help.

Keith

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Paul_Pitzonka
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Paul_Pitzonka 1/9/2021 5:20am
1/9/2021 5:20am
kb22 wrote:
Well I’ve done the oil every ride and air filter every ride so I guess the guy before had lack luster maintenance. I’ll re-check tonight after...
Well I’ve done the oil every ride and air filter every ride so I guess the guy before had lack luster maintenance. I’ll re-check tonight after work but idk how much more tdc I can get. Recommendations on going with a re-cut over a shim? I have been eyeballing Williams motorworks. Thanks again for the help.

Keith
How thin are your shims?
kb22
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kb22 1/9/2021 9:27am
1/9/2021 9:27am
Honestly, I bought this bike in June and it was insanely clean but like every 4-stroke I looked at the po had only tracked the oil changes. So I’m not sure how many hours are on it and would assume it’s the stock shims. But I haven’t removed the cams to look at this point. Unfortunately the wife and I work opposite shifts as RNs so I get an hour once a week to get after it.
kb22
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kb22 1/9/2021 5:58pm
1/9/2021 5:58pm
The exhaust is about .03 on both maybe less and that’s about the same for the intake. So it seems like I would need some thin shims? Thanks in advance
Paul_Pitzonka
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Paul_Pitzonka 1/9/2021 6:20pm
1/9/2021 6:20pm
kb22 wrote:
The exhaust is about .03 on both maybe less and that’s about the same for the intake. So it seems like I would need some thin...
The exhaust is about .03 on both maybe less and that’s about the same for the intake. So it seems like I would need some thin shims? Thanks in advance
You need to pull the buckets and check the actual shim size not just the clearance.
kb22
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kb22 1/9/2021 6:30pm
1/9/2021 6:30pm
I just started that, I’ve got another 12 tomorrow and afterwards I’ll pull the cams and check them out and update. I’m hoping it’s just a shim and then I can do a top end and be good for a little while longer.
kb22
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kb22 1/10/2021 5:31pm
1/10/2021 5:31pm
Alright I got it all apart here are the measurements. Let me know if I’m on the right track.
Paul_Pitzonka
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Paul_Pitzonka 1/10/2021 5:59pm
1/10/2021 5:59pm Edited Date/Time 1/10/2021 6:01pm
Based off the use of hotcam shims and the shim thickness it would be safe to say it’s been shimmed prior and It’s very possible whoever shimmed the valves prior may have shimmed them incorrectly... You have plenty of room left to shim them and bring them back to spec...
kb22
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kb22 1/10/2021 7:40pm
1/10/2021 7:40pm
Yeah the one numbered three looked different I was thinking stock? I’ve got the buckets back in but the caps have been difficult and I’ll have to wait until tomorrow night to re-check. Hopefully these are the correct shims and everything bolts back up nicely. Thank you for the help and I’ll report in with how this goes.
kb22
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kb22 1/13/2021 6:23pm
1/13/2021 6:23pm
Just an update: got all the valves smack dab in the middle except the shifter side Intake, it was less than 20 but greater than 18. I figured close enough and it ended up an entirely new bike! Thanks for the help!
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