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Mnbluepitsyz450f

Valved clearance adjustment help

17 posts in this topic

Hello everyone i done search and searched before i poped this question out here in the forums.. here it goes I just traded my 77 chevy for this yz 450f bike the guy gave me all the recites showing that he just rebuild it over winter (plus hes a ex racer and owns his own shop) he told me to check the clearance in 10 hrs of running that it had ruffly 30 to 40hrs of break in he said ... Well im not a mechanic i can follow what i read pretty well the manual told me

VALVE CLEARANCE (cold):

0.10 ~ 0.15 mm

Example: Installed is 175

Measured clearance is 0.22 mm

Replace 175 pad with 185 pad

Pad number: (example)

Pad No. 175 = 1.75 mm

Pad No. 185 = 1.85 mm

ok i tried to shim in the spot it told me aqnd i couldnt even get a 0.10 in on either side.. how do i go about finding the right one i need? to put in do i start at 175 and go up till it meets a gap of 0.10 and 0.15 or am i missing something plz help this noobie out before i trash a nice bike :thumbsup:

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you go down in pad numbers. Example if you have .09mm clearance and a 175 pad you want to go to a smaller pad size, they go in .05 increments so go to a 170 pad number but don't trust the number use a micrometer. I would suggest buying a Hot Cams shim kit from your local dealer.

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Make sure your on tdc and make sure the cams line up before you put it all back together and also check the clearances before you put the valve cover and ect back together.

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Hello everyone i done search and searched before i poped this question out here in the forums.. here it goes I just traded my 77 chevy for this yz 450f bike the guy gave me all the recites showing that he just rebuild it over winter (plus hes a ex racer and owns his own shop) he told me to check the clearance in 10 hrs of running that it had ruffly 30 to 40hrs of break in he said ... Well im not a mechanic i can follow what i read pretty well the manual told me

VALVE CLEARANCE (cold):

0.10 ~ 0.15 mm

Example: Installed is 175

Measured clearance is 0.22 mm

Replace 175 pad with 185 pad

Pad number: (example)

Pad No. 175 = 1.75 mm

Pad No. 185 = 1.85 mm

ok i tried to shim in the spot it told me aqnd i couldnt even get a 0.10 in on either side.. how do i go about finding the right one i need? to put in do i start at 175 and go up till it meets a gap of 0.10 and 0.15 or am i missing something plz help this noobie out before i trash a nice bike :thumbsup:

The example given in the manual is a bit confusing to a someone new at it. The manual is giving an example of a valve that needs to be tighteed up witch with these bucket style valves is never going to happen. They only tighten up into the seat making the clearance tighter. So you need to put a smaller shim in. Hope this helps.

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Ok thank you very much .. so i go down in size till i get the gap back to 0.10 and 0.15?

Correct just go down one size at time and then turn motor over slowly a few times to set the parts in place and then check the clearance. I see your from Minnesota are you going to be racing D-23?

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Start with engine against the compression stroke, the flywheel mark lined up at TDC, and the lobes of both cams pointing "up and outward". If you can't get a .10mm (.004") feeler under any one of the intake cams, or a .20mm (.008") under one of the exhausts, then use a smaller feeler gauge until you find one that does fit with a slight drag under it. If you find that an .05mm (.002") will not fit, then go two sizes smaller one the shim (from a 185 to a 175, for example) and remeasure.

If you find an intake that measures .05mm (.002"), and it has a 185 under it, change that shim to a 180 (.05mm smaller) and you will then have a clearance of .10mm.

Be EXTREMELY careful with the cam caps:

  1. There is a half circle locating ring under each cap at the ball bearing. Watch for this and do not allow it to fall into the engine (stuff a rag in the chain tower).
  2. Always push the cam caps back down into place with your fingers ONLY. NEVER draw them down to seat by tightening the bolts.
  3. ALWAYS torque the caps in the prescribed sequence to NO MORE THAN 7 ft/lb (84 in/lb)
  4. NEVER turn the engine over with the chain tensioner slackened

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I see your from Minnesota are you going to be racing D-23?

No ill just be trail riding but after reading the post grayracer513 posted :thumbsup:

Anyone close to cloquet mn here next month wanna help a feller out lol!!

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VALVE CLEARANCE (cold):

0.10 ~ 0.15 mmExample: Installed is 175

Measured clearance is 0.22 mm

Replace 175 pad with 185 pad

If his measured clearance is 0.22mm, shouldn't he need that 185 shim, or something thicker than his 175? Now, I'm kinda going on the assumption he's talking about his intake valve clearance here, since he posted a clearance zone of .1 to .15mm.......

Jimmie

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i did under both cams like it showed in the pic!

100_0132.jpg

100_0135.jpg

100_0136.jpg

Something else i noticed left cam looks to be off alittle?

100_0138.jpg

100_0139.jpg

100_0140.jpg

Edited by Mnbluepitsyz450f
edited for pics

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If his measured clearance is 0.22mm, shouldn't he need that 185 shim, or something thicker than his 175? Now, I'm kinda going on the assumption he's talking about his intake valve clearance here, since he posted a clearance zone of .1 to .15mm.......

Jimmie

I think you will find that the text in his post is a quote from the service manual given as an example. He said he couldn't get a .10mm under any of them.

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No ill just be trail riding but after reading the post grayracer513 posted :thumbsup:

Anyone close to cloquet mn here next month wanna help a feller out lol!!

I live in Cloquet...small world. Let me know if you still need a hand.

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I think you will find that the text in his post is a quote from the service manual given as an example. He said he couldn't get a .10mm under any of them.

Correct

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powers450f Lol real small world !!! yea i dont get paid again till the first then ill run down to rj's and buy some shims then ill get back at ya if you dont mind..

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Hey haven't had a chance to catch up been running around trying to get my bike ready for Grantsburg this weekend.

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