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Checking valve clearence - Really confused ?????


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1st off, bike has about 27 hours on it and I do have it on the compression stroke BUT when you line the punch mark up on the crankshaft with the crankcase cover the mark on the cam sprocket is about 5mm higer then the mark on the cam holder. I rotated it 3 times and it always ends up like this. So which is more important to line up? One way or the other one of the marks will be off. Do your's line up exactly?

A freind suggested it might be off by one tooth and ya know if I did move it one more tooth it look's like it would then be spot on but is this possible from new? I remember all my other 4 strokes were spot on. He also stated it would still run and just have a slightly different power output then normal.

I checked the exhaust valves both ways and get .014 or .356mm so it seem's it doesn't make a difference which marks you line up?? Intake I can't even slide the thinnest angled gauge through which is .005. At .014 are the exhaust close to what they shold be?[/b]

I really need help in converting all this to measurements in the book! I don't understand why I can't slide anything through the intake side either?

Valve specs from SERVICE MANUAL for intake are: 0.16 +or- 0.03mm (0.0063 +or- 0.0012in)

Exhaust: 0.28 +or- 0.03mm (0.011 +or- 0.0012in)

<font color="brown">I have no idea how to convert this over to the .012 (example) 3 digits on my guage or in 3 digit mm.

If someone would be so kind to explain this all to me. Guess I need a refresher course in math. ๐Ÿ™‚ Hope T.T. has some excellent mathematician's out there that can teach me??

1st things 1st! Once I get this figured out then my next post will be about what shims I need??

Guess I'll be the 1st to post have a merry xmas and a happy new year!!!

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I don't know on the marks, I just lined up the marks on the crank and never paid attention to the cam marks.

On the measurements, the intake should be .005-.007 (basically .006 + or - 1 thousandth), and the exhaust should be .010-.012 (basically .011 + or - 1 thousandth)on your feeler guages. Just ignore the mm measurements unless you have those type of feeler guages. If your intakes are tighter than .005 then they are out of spec. and need to be re-shimmed. Letting them get tighter will result in a burned valve. You need a feeler that goes lower than .005 so you can see what your clearance is, so that you will be able to measure your shims and order the correct size replacements. For example, if the valves are at .003, or 3 thousandths too tight, then you need a shim 3 thousandths thinner. You can't figure out what shim you need without knowing the existing clearance.

Hope that helps some.

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Then mine are all screwed up at 27 hours or so on the bike!

Intake: right side- clutch side .004 Left side I can't even get a .002 through it and have none smaller! How do you even measure any smaller and is this normal?

Exhaust: both at .014 A .015 will slide through but it's tight. Sort of got to push it hard to get it to slide through so I guess it's considered .014

Just curious what a shop charges to do this? That's with it of course taken down to the valve cover being off. I don't want to take it and learn it myself but how in the world do I figure out what size shim for the left intake if I can't get a .002 (smallest one I have) to slide through???? Anyone else run into this? You guy's may have noticed I repeat things alot. That's just so the story get's drilled into your heads right and I'm assured the correct answer! ๐Ÿ™‚

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My local bike shop charges $100.00 to adjust. I am not experianced with 4-stroke bikes and the CRF is designed weird in that you have to remove everything first including the entire rocker arm assbly. I'll spend the 100.00 instead.

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Huffa, I thought it was strange that the mark on the cam chain sprocket was about 5mm above the other mark on my bike as well. I even put a pencil in the spark plug hole to make absolutely sure I was at TDC. Tried moving the cam chain over 1 tooth out of curiosity and this made it obviously way off. I then took my friends 03' CRF apart to check it out. Exact same thing. I guess Honda wants you to look at the marks from slightly above (so that they line up) rather than exactly perpendicular to the engine ๐Ÿ™‚. Oh well, bike runs excellent.

Sounds like your exhaust valves are too loose and the intakes are too tight. I reshimmed when my intakes went to 0.004-inches. My feeler gauges go down to 0.001-inches and sounds like you need some like this to find out what yours is on the one side. It really is very easy to reshim the valves....as long as you can measure what they are now. Sounds like you need all four shims. That would cost around $20 and should take about 45 minutes.

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Oh yeh. You also probably need a micrometer to measure the existing shim thickness. I could not read the numbers on two of my shims. I guess this may sound complicated. I luckily just had all the tools I needed. After taking my bike apart to check what shims I needed (needed both intakes and one exhaust), I ordered the parts, waited 3 days, paid my $15, and went home to tackle the job. Once I had the shims on hand, it only took about 45 minutes total from taking the gas tank off to starting the bike back up to check.

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Well, if you're tighter than .002 then you don't really need to know, just use a shim .006 thinner than the one you have...if you are at 0 clearance now you'll be dead on at .006 then, and if you are at .001 now then it would put you at .007, which is within spec also, and will allow more time before another adjustment is needed.

So, you need one shim .006 thinner than the shim on the '0' clearance valve and one .003 thinner than the shim on the .004 clearance valve.

If you are at 0 clearance though I'd have someone look at the valves before just putting in new shims...that very tight valve may need replacement if it has been run like that for long.

I hope that was clear, it's easier to think than put in words.

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You guy's have all been a big help!!!!! I AM going to tackle this !! Anything seem's complicated at 1st till you do it once or twice!

Some just take it to the dealer which is fine but I can't keep taking it to the dealer every time my valves need adjusting. Besides that, the 100 bucks they charge I can buy an awful nice micrometer (Any to recommend?) + other tools.

O.K. I learned alot already. Now what MXaddict said about the tight valve needing replacing could very well be a possibility and that would of course change shim size. Guess we won't know till I take head off and inspect but it seem's with the 0 tolerence that is not a good sign and doesn't make me a happy camper as the bike is LOW hour's for an 02.

That will be my task today then - to remove the head. Stay tuned to Stage 2 to the following saga of " As the wrench's turn " and please inform me anything else you think of.

<font color="brown"> Thank You ALL! - Huffa

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I'm on stage 2 (head removal). What tool can be used to take the place of the one in manual referring to it as the stopper tool for the use of cam removal I guess? What exactly does it stop?

It say's to turn lifter shaft fully clockwise. How fully, 360 degrees or what?

Keep in mind I'm getting this off the service manual and NOT the owner's manual so it might be slightly worded different. .

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I just used a small screwdriver that fit and a small set of vicegrips to hold it.Just turn it in clockwise until it stops,you'll feel when to stop.I just clamped the vicegrips on the screwdriver and rested the vicegrips on the case in front of the countershaft sprocket.Held for a week while I waited for the shims.My intakes were tight(.005left/.004right) after the first 12 hours on my '03.I think that's typical for a new motor but I'll be keeping an eye on it though.

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Hoffy

I'm sure I can get one for way under a 100 that's why I stated I'll still have $$ left over for other things.

Interesting odditiy I found on camshaft sprocket mark or marks I should say. Remember I said when lining the cam sprocket mark up in conjuntion with the crankshaft and the mark was off about 5mm on the sprocket? You do remember, ok then good I'll proceed. When taking the sprocket off I noticed there are 2 marks and not 180 degrees apart but more like 185. So I got to thinking - the other mark is down the exact distance I was saying it was off so I put sprocket back on 180 degree's to the other mark and PRESTO!! it lined up perfect! I'm not saying I'm going to install it that way but don't you find it strange that everything lines up how it should be. Could honda have had it turned 180 degree's to the wrong mark from factory? I just don't know, you tell me???

<font color="brown"> T.Rex, Thanks for the explanation on the cam adjustment also. I used a slightly different method to hold it there. My 5 and 1/2" screw driver came within a 1/2" of the top swingarm chain roller so I had wooden shims laying around and just wedged them in between driver and roller and screw driver is now locked in place.

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Huffa, just got my bike back together tonight. I had to split the cases again----crank, long story. At any rate I noticed my marks never line up that great either. Something like the 5mm off you are talking about. Starts and runs fine though. RR.

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The wife works at the dealer where I bought the bike.I asked the service manager if he saw this in other Honda's and he said yeah they suck with that.So I felt like an idiot after taking mine back apart three times to make sure,even moved it a tooth each direction.No good.So they just don't line up exactly.Oh well like RR said starts and runs great so ???.

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Those cam marks were a PITA for me also. I never did get them where i thoght they were lined up exactly. Next time I take it apart I will scribe a new alignment mark and then it should go back without all the head scratching[my head]. 5 hours on the BD valve kit.All is well

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I keep saying if you rotate it 180 degrees the other mark lines up almost perfect so you really wouldn't have to scribe a new line, just rotate it. Why there are 2 I haven't come across an explanation from anyone yet.

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