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Exhaust valve clearance question

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My exaust valves have a clearance of .005 on the right and .003 on the left. They have been like this since 20 or so hours after it was new. I got my dealer to replaced the valves this winter when I rebuilt my engine a 150 hours. When I got the head back from the dealership, they said the valves were fine but replaced them anyways because I asked them to. I measered the clearance again, and it was still the same. Is this ok to run it like this. They don't make a shim that is the right size for this clearance. I was told by the dealer, that this is alright. The bike starts and runs great. Any input on this would be a good. Thanks.

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Put it this way.Spec is .011 I run Mine at .008 as my mechanic suggest. He says the book is to lose.Why I don't know,but .008 to .012 works..012 is kinda sloppy.He say's he sets some of his race bikes at .005 int and .005 exh.Hard starts but more power.I would say your exhaust are tight.Specialy.003.Hot cams shims come in.005 increments wich normaly moves your valve lash.002mm.They make the shims for the size you need.

A:new shim thickness

B:recorded valve clearance

C:specified valve clearance

D:old shim thickness

A=(B-C)+D

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Maybe you meant to say your "intake" valve clearance? Anyway, my left intake valve is .003 and the right is .005, possibly just like yours. Its been like this since new, neither left or right has moved. My exhausts are at .011.

I have had no trouble so far, the bike starts and runs great, but have wondered the same.

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Maybe you meant to say your "intake" valve clearance? Anyway, my left intake valve is .003 and the right is .005, possibly just like yours. Its been like this since new, neither left or right has moved. My exhausts are at .011.

I have had no trouble so far, the bike starts and runs great, but have wondered the same.

I was wondering that myself.Intake?

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Exhaust valve clearance is typically set about double what intake valve clearance is set at due to the extra heat the exhaust valves are subjected to which causes additional expansion.

I wonder if there is a possibility that the cam is rotated slightly when you are checking the clearance, and you are actually on the ramp for the lobe.

Clearances should be checked with the peak of the lobe pointing away from the rocker.

Whoever told you that thinner shims are not available is nuts. If you do in fact have insufficient clearance then ordering thinner shims can be done at any Honda dealer, that knows what they are doing.

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Maybe you meant to say your "intake" valve clearance? Anyway, my left intake valve is .003 and the right is .005, possibly just like yours. Its been like this since new, neither left or right has moved. My exhausts are at .011.

I have had no trouble so far, the bike starts and runs great, but have wondered the same.

No it is the exhaust clearance, and I measured is properly, and it was at TDC. It's pretty bad, but I'm not sure why it still runs fine. It is a tiny bit hard to start when left sitting for a few weeks, but other than that it runs good.

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I would stay within .001 of the Honda specs, and like others have said, be sure you are measuring the clearance correctly. The Hot Cams shims are in increments of .002 (.05 mm) and the kit has any size you could possibly need. Honda apparently doesn't sell an assortment of shims, so I've found that what most dealers have on hand is hit or miss. Also be aware that with the titanium intakes, the springs are weak enough that a .005 feeler guage can compress them if shoved in forcefully--you only want to feel a lite drag.

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No it is the exhaust clearance, and I measured is properly, and it was at TDC. It's pretty bad, but I'm not sure why it still runs fine. It is a tiny bit hard to start when left sitting for a few weeks, but other than that it runs good.

Geez... something smells here. Doesnt seem right to me that a dealer would adjust the exhaust valves so tight and then blow you off with a shim excuse. Just seems wrong to me.

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I checked the clearance again today, and found the CRF 250 Shim Calculater on the crfsonly site. I put all my info into the spreadsheet, and it gave me the size of shims and the part number for them. I will order them tommorow. Thanks for your input and help.

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If you are going in from the side or the front, your reading will be tight. You have to put the feeler gauge in from the opposite side. You have to put the gauge in the right side of the left shim and the left side of the right shim, if this makes sense.

I dont know if this how you are doing it, but i read a lot of guys getting the same tight reading when going in from the side but once they go in the other way it`s right in spec.

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If you are going in from the side or the front, your reading will be tight. You have to put the feeler gauge in from the opposite side. You have to put the gauge in the right side of the left shim and the left side of the right shim, if this makes sense.

I dont know if this how you are doing it, but i read a lot of guys getting the same tight reading when going in from the side but once they go in the other way it`s right in spec.

What? can someone explain? this don't sound right and theres only one or two ways you can actually get a feeler gage in, from the front or on the side.

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There are 3 sides to put the gauge in. If your standing over the top of your bike looking down at your left valve, you can put it in from the front, you can put it in from the left side, or you can stand on the right side of the bike and slide the gauge in the right side of the left shim.

The last way is the way i do all 3 of my CRFs, when i first got the bikes i could not get the right size in there when goin in from the side. I put the gauge all around the shim untill i found this out. I`ve read on this site and others of people haveing tight readings on their exhaust valves but once they do it this way it will come out alright.

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There are 3 sides to put the gauge in. If your standing over the top of your bike looking down at your left valve, you can put it in from the front, you can put it in from the left side, or you can stand on the right side of the bike and slide the gauge in the right side of the left shim.

The last way is the way i do all 3 of my CRFs, when i first got the bikes i could not get the right size in there when goin in from the side. I put the gauge all around the shim untill i found this out. I`ve read on this site and others of people haveing tight readings on their exhaust valves but once they do it this way it will come out alright.

I still don't see where it makes a diff,I'm not getting it but don't waste your time on me.The only thing i see here,is on your exhaust valves you need to be

carefull on not going under the shim.Thats where people get their tight or screwed up readings.You need to be between the rocker arm and the shim.On the intakes you have shim buckets over the shim and it doesn't matter how you slide your gage in.

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If you are going in from the side or the front, your reading will be tight. You have to put the feeler gauge in from the opposite side. You have to put the gauge in the right side of the left shim and the left side of the right shim, if this makes sense.

I dont know if this how you are doing it, but i read a lot of guys getting the same tight reading when going in from the side but once they go in the other way it`s right in spec.

I did it this exact way.

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Keep in mind that the clearance set on the valves also playes a role in your cam timming.. If your gap is too big then your valve will open later,probably by a couple of degrees...That makes a diffrence in were your power comes on.Just as a tight clearance will open the valve sooner and could even stay open slightly as the valve heats up and expands....My prefrence would be a little loose than a little tight.. Loose makes noise and tight recks valves.

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Keep in mind that the clearance set on the valves also playes a role in your cam timming.. If your gap is too big then your valve will open later,probably by a couple of degrees...That makes a diffrence in were your power comes on.Just as a tight clearance will open the valve sooner and could even stay open slightly as the valve heats up and expands....My prefrence would be a little loose than a little tight.. Loose makes noise and tight recks valves.

I like what you have to say. I didn't really ever think about the timing effect. I know it's suttle but it might be enough to make a difference.

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