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Camshaft Holder Wear

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Old 09-13-2023, 08:07 PM
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Camshaft Holder Wear

I'm seeing some wear marks on the camshaft holder cap bearing surface furthest from the cam gear; front cylinder exhaust.
The valve clearance was running a bit tight there; it was at .010 instead of the .012 spec.

No failures or catastrophes; it was running good actually.

I would think that only .002 off wouldn't have that but I don't know these bikes too good.

What think some of you of greater VTR knowledge?

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Old 09-16-2023, 06:42 AM
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Originally Posted by GreyWater
I'm seeing some wear marks on the camshaft holder cap bearing surface furthest from the cam gear; front cylinder exhaust.
The valve clearance was running a bit tight there; it was at .010 instead of the .012 spec.

No failures or catastrophes; it was running good actually.

I would think that only .002 off wouldn't have that but I don't know these bikes too good.

What think some of you of greater VTR knowledge?
What type of CCT's are installed?
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Old 09-17-2023, 12:19 AM
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It has been running with factory auto tensioners.
I was checking valves and had decided to install some manual tensioners.

Speaking of which, I never liked how the factory Honda tensioners worked in the motor. The cam chains end up running way too tight, in my opinion anyhow.
I noticed this last time I had the bike apart and the same thing now; I removed the auto's did what ever I had to and when I re-installed them, with no load on the cam chain, TDC, the tensioners would tighten up to what looked appropriate. But, just by turning the motor by hand or after some running time, I see that they have tightened up considerable more. I don't get it. Wonder if this had something to do with some of them having failed.

Anyhow, on the cam holder thing, I must have installed, removed and checked the mating surfaces half a dozen times. Doesn't make sense to me.

Edit; I do have a dial indicator, magnetic base type; but, no unit to hold and spin the camshaft in to test runout.
Edit #2; What I discovered as well is that this exhaust cam, on the front cylinder, will not turn by itself once it has been installed and the cap torqued to spec, The other 3 will, just from the off center weight of the cam lobes. this cam needs a slight pressure to turn in the head. It may always have been like this and I didn't notice it last time I was in there. maybe there is a slight warp in that part of the head(unlikely), maybe a defect from the factory( also unlikely).

Or, like my old buddy used to say, the Ford man; "Just effing run it hard and forget about it"......

Last edited by GreyWater; 09-17-2023 at 01:03 AM.
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Old 09-17-2023, 06:12 AM
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Can't help thinking that the Honda engineers know what is optimal. On the other hand the bean counters did have their say in how good parts needed to be.
The auto CCT's do seem to apply a lot more tension to the chain than properly set manuals. Which is ~5mm or so of chain slack between the gears. I found this out recently when checking clearances and changing back to autos with the stopper mod installed.
Wonder if it's an issue with oil and/or circulation.
Did both the front exhaust valves have the same clearance?
What is the mileage on the engine?
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Old 09-17-2023, 08:13 AM
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Just making sure every time you were in there, those caps were returned to their original location and orientation? And out of curiosity, how did you measure the chain tension after installing manuals?
Can you share a pic of this wear?
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Old 09-17-2023, 08:12 PM
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Haven't been working on my SuperHawk this weekend; It was really nice up here where I live so I took advantage and went riding in the mountains, because, I'll be looking at snow soon enough........

I thought about the oil circulation as well. I proved that the camshaft oiling passages were/are clear. As I understand it, camshaft/cam holder oiling comes from the head up through the tabs on the holders; I reason that if the camshaft is clear and the bearing surface closest to the cam gear is fine then oiling should be fine. But, I am going to recheck the cap passages( just to be sure)

As far as clearances go; the numbers were at .010"; front right(riders right) was at .011". The motorbike is fairly young; 27,000 Km/16 or 18 thousand miles. All the valve clearances were out equally between the two cylinders. Each had 1 intake at .005 and the other was on the money; both cylinders had 1 exhaust at .010" and the other at .011"

As far as parts not going in from whence they came; that's not it. See, I did the front cylinder, found this issue, re-shimmed, put the valve train together, temporarily using the existing auto tensioner and moved on to the back hole. I didn't like the metal centered tensioner gaskets that the Ape came with(no good reason, just didn't like them) so I ordered some Honda gaskets as well as 2 of the new shims that I was needing. Everything is here now so I'm ready to get back at 'er. So ya, I haven' t installed the red Apes yet. But here is my thinking; if I press down, then pull up hard on the chain and the gear to gear gap deflects 5mm in total, than I would consider that barely acceptable and would probably tighten it up just a hair more.

I thought about taking a pic when I posted this but didn't. I can though; it's no big deal to take the front chain and cap/caps off again; I've got to replace the old tensioner in the front still after I finish up the back one.

One more bit of info on that problem cam and holder. When I was playing around with it I was able to crisscross torque the cap to about the 15-16 N/m range and everything looked happy, but as it got close to 20-22 that is when the cam started to bind.

Last edited by GreyWater; 09-17-2023 at 08:17 PM.
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