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Discussion Starter · #1 ·
Just how important is it for the clearances to be within specs?

I checked mine this weekend ('02 with 61,000 miles) using Fred's videos as my guide and this is what I came up with. All of the exhaust valves are .008" (the tight side of the specs). Three of the intakes are .005" (tight side of the specs) and three of the intakes are .004" (too tight).

Someone tell me how critical this is and should I be concerned?

--Bill
 

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Sounds like you have all the info you need to collect the shims needed to get them in spec. The ones that are in spec, even at the edge of spec are certainly OK. The ones that are out are out and should be reshimmed. Some of us took the unnecessary time and effort to center spec ours -- total folly, but gets you that warm, fuzzy feeling. Working with the shims is not difficult. Just take care to carefully note your cog positions and to blow any excess oil out of the shim seat in the bucket before setting the new shim in; so you get an accurate reading when you verify the new clearance. Will it blow-up if you don't do this, I doubt it -- but why even check if you are not going to take action to correct?

prs
 

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Grumpy Fart
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As the engine heats up, the clearances become smaller. If the clearance disappears and the valve stays open, performance drops and valve wear greatly increases. It is much more costly to pull the heads and redo the valves than take the time to properly set the clearances.
 

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Just how important is it for the clearances to be within specs?

I checked mine this weekend ('02 with 61,000 miles) using Fred's videos as my guide and this is what I came up with. All of the exhaust valves are .008" (the tight side of the specs). Three of the intakes are .005" (tight side of the specs) and three of the intakes are .004" (too tight).

Someone tell me how critical this is and should I be concerned?

--Bill
Those +/- specifications are there for a reason, I would at the very least adjust the ones that were out, while you have it apart you might as well bring the others up to around the center of spec. I adjusted my 02 at around 60,000 miles and all the exhaust were out and 4 of the intakes were on the bottom of the spec. and regardless of what others might say, I did see an improvement in the way it ran.
Just my opinion, others may vary.
Paul H
 

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I'd agree with the previous two posts, if they are out of spec or borderline then get the right shims. You've already done most of the hard work getting at them for the check, it's not a big second step to do the shims.
 

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Discussion Starter · #6 ·
OK, that's settled. I'm going to get 'em back where they should be.
I read a post a while back where someone asked about sanding the old shims down. I don't remember the answer. Any reason not to give that a try?
Thanks for the input.
 

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That would likely screw-up the surface hardness and allow excessively fast wear. Just get a shim kit or order the ones you need from Hal.

prs
 

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That would likely screw-up the surface hardness and allow excessively fast wear. Just get a shim kit or order the ones you need from Hal.

prs
I certainly wouldn't sand them either, but unless they're hard-coated or plated, it's the same hardness thru the shim.
 

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Vendor
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If you have to pull a cam to swap shims, you should go ahead and set EVERY VALVE on that head as close to center spec as you can. This will increase the time interval before they go out of spec.

Don't just set the ones that are out of tolerance. Do them all. You have the cam out anyway, there is no reason not to.

The Honda shims come in .025mm increments, which equates to about 1 thousandth, so the smallest change you can make is .001 inch to any valve. If an intake is at .005, go ahead and drop the shim in it down one size to bring it to .006 (center spec). Do this with EACH valve in the head, not just the ones that are out of spec. If you don't you will just have to come back and do it again in 30K miles. Also, setting them all as close to the same (center) spec as you can, will make the engine idle and run smoother and increase gas mileage.
 

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at 61,000 miles if u set them all near the center range u will very likely never need to adjust them again
 

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OK, that's settled. I'm going to get 'em back where they should be.
I read a post a while back where someone asked about sanding the old shims down. I don't remember the answer. Any reason not to give that a try?
Thanks for the input.
i would guess the shims have a rockwell hardness of 58 0r more. i am going to do mine on a surface grinder. cuz i can hold ten thousanths. you could sand them but you will have to mike the thickness around the whole outer edge to maintain uniform thickness and if they are as hard as i think they are you will be sanding the rest of your life to remove .001 ". if you don't have access to a surface grinder with a magnetic chuck and a cbn wheel, i would buy new shims. i would say they are not surface hardened, just heat treated and then finish ground, so they will be the same hardness all the way through. bill
 

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Discussion Starter · #13 ·
Ok, done! I read Fred's post about changing all of them after I finished, but that's what I did. Went to the Honda dealer to get the necessary shims and he tells me he doesn't stock the half-sizes. Says they use after-market shims which only are in .005 increments. So I got the exact ones he had that I needed and erred on the loose side for the others. All of my exhaust clearances are now in the .009 -.010 range and the intakes are all .007. So I feel good about that.

Thanks to you all for encouraging me to go ahead and finish the job right. I really was reluctant to remove the camshafts, but it worked out alright.
 

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WOW I haven't looked into the valve adjustment on the Goldwing before seeing this post. From what i read this sounds much more involved then the adjustments made on the VTX
I am unsure of how the 1800VTX is done, but the GL1800 is actually easier to check than is the VTX1300 because of the cramped space the 1300 presents. Neither one is difficult, just tedious and requires attention to detail. Adjusting a shim in bucket design is a bit more involved, but actually needs be done far less often. The "scariest" part of the GL1800 procedure for me is to NOT strip the valve cover pan screws, especially the front ones, they are notoriously weak -- I have done this three times and so far, so good; although I did replace one front cover bolt and ran a rethread tap in its head threads because I thought it felt "funny" -- it was probably OK - just the gasket giving a bit. My VTX is due again soon, so I had better gather up my little wrenches and tie some string onto them ;-)

prs
 

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If you have to pull a cam to swap shims, you should go ahead and set EVERY VALVE on that head as close to center spec as you can. This will increase the time interval before they go out of spec......
However, comma, if you're lazy (as am I) AND you ride the bike a lot (as do I), you MAY consider setting the clearances to the max allowable.

That way, you may never need to pull the camshafts again.

That's my plan when/if my bike ever requires one or more shim swaps (so far so good, though).
 

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Valve adj

I started the valve adjustment on my VTX1800 yesterday and did all the desmog removal and finished the front cylinder valves. They were all right on spec. I ran out of time for the rear cylinder and I am dreading it with the lack of space. It looks like it will be a real pain. I will have to watch the video on the GL to see how it compares.
uga
 

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About how much time is involved to do all the valves ????????????
 

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Valves cool during the millisecond contact they have with the valve seat. The tighter the clearance the hotter the valve runs. Hot valves can warp a stem. It also leads to permature wear of the valve surfaces, valve guides and stem seals. You can also burn a hole inthe old ones. Loose clearances lead to premature wear and a lose of performance.

THe Volkswagon Beatle taught me this. You adjusted valves every 3,000 miles. Remember the pre 1971 exhaust valve on #3 is supposed to be .001 looser than the others.
 
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