valve adjustment


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morg56
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valve adjustment

Post by morg56 »

I'm trying to check the valve clearance on my 79 cbx . I have tried to follow the honda manual . I get confused were it say's " open no. 2 ex valves to maximum ". My question is how do you know you are right at maximum ? It seems as you turn the crank it's hard to tell were max is . There does not appear to be a mark on the crank or anything .Any help is appreciated .

steve murdoch icoa #5322
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Re: valve adjustment

Post by steve murdoch icoa #5322 »

Best money you can spend is to purchase the Mike Nixon valve adjustment book.
Many photos and detailed descriptions.
https://www.motorcycleproject.com/text/ ... valve.html

EMS
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Re: valve adjustment

Post by EMS »

Engine 101: A valve is at max open when the tip of the cam lobe points vertically down on the valve shim.

morg56
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Re: valve adjustment

Post by morg56 »

thanks for the imput . Like I was saying it just seems not very accurate to just eye ball the cam location ,but if that is what has worked for years I'm ok with it . One other question now . So , say you have checked all the clearances and filled out your chart ,so now you need, lets say to change 7 shims. But you still don't know what size shim is in the bucket . Can you take out each shim , measure it and keep track of where it came from .then go get the 7 new shims that you need and install them . Or do you have to take out one shim ,measure it ,go get the replacement,put it in ,then move on to the next ? Sorry if this sounds like a dumb question ,but it's not spelled out in the manual ,I'd rather ask then break something and feel stupid for not looking into it . Thanks

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cross
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Re: valve adjustment

Post by cross »

That’s exactly how you do it if you don’t know what’s there. Measure the gap, wrote it down, take the shim out, measure it and write it down. When done calculate what shims you need to get to 0.13mm and make a plan on which existing shim you’ll reuse and where. When you’re done, record shim sizes so you know what you have in which position for next time.
DO NOT rotate the engine with shims removed.
Sasha

'82 Honda CBX
'99 Triumph TBS
'01 Honda Valkyrie

:auto-sportbike:

steve murdoch icoa #5322
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Re: valve adjustment

Post by steve murdoch icoa #5322 »

There are a couple versions of the valve adjustment spread sheet to make the job easier to track.
http://www.cbxclub.com/protect/valve.pdf

viewtopic.php?f=25&t=9208&p=80478&hilit ... eet#p80478

morg56
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Re: valve adjustment

Post by morg56 »

I'm sorry but I'm still confused . How do you "Measure the gap, wrote it down, take the shim out, measure it and write it down." but also follow these rules " DO NOT rotate the engine with shims removed " It seems to me you will have to rotate the engine as move from one set of valves to the next ,taking out the shims if you have to . Please clear this up for a simple guy from the north . Thanks

jnnngs
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Re: valve adjustment

Post by jnnngs »

morg56 wrote:
Tue Jan 05, 2021 7:14 am
I'm sorry but I'm still confused . How do you "Measure the gap, wrote it down, take the shim out, measure it and write it down." but also follow these rules " DO NOT rotate the engine with shims removed " It seems to me you will have to rotate the engine as move from one set of valves to the next ,taking out the shims if you have to . Please clear this up for a simple guy from the north . Thanks
For each valve where the clearance / gap is not to spec:
- rotate engine so that valve is at it's maximum gap / clearance (so when lobe is pointing away from the shim)
- measure the clearance / gap and write it down
- take the shim out, measure the shim size (using micrometer or similar) and write it down
- put the shim back in and then move onto the next valve which needs adjusting
- repeat as above

Then you can work out:
- what shim size you need for each valve to get the correct clearance gap
- then see if any of the "incorrect" shims can be used in another valve
- and order the remaining ones if existing ones cant be used.

EMS
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Re: valve adjustment

Post by EMS »

For one thing: I always do only one valve (or maybe two) at a time. Do NOT turn your engine without a shim in the bucket.

morg56
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Re: valve adjustment

Post by morg56 »

thanks for the help ,it makes sense now . Fairly involved process ,but I should be able to do it now . Thanks again.

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