Timing- / cam-alignment, new CCT's, valves...

[vivec]

Hi all,

Been reading many many forum-topics about the dreaded CCT failures.

While riding at about 40Km/h my bike suddenly, out of the blue (worked like a charm before) started to puff-tick-clankish-sound from the bottom front (hard to say exactly while on the bike, being a bit startled by the phenomenon)...

Soooo... beforehand read a lot already about CCT's, but never got around to changing the original Honda ones. After hearing the sound, I immeditately pulled the clutch, stopped the bike and put it off. Never starting it afterwards...

Last week I began the journey of taking the bike apart for the first time. I actually enjoyed that .
viewtopic.php?t=28583 --> Thank you so much!!

Now, the rear cilinder cams look fine, but the fronts... ouch... They're out of sync even without having measured them precisely.



My question is this:
I will need to realign these cams first. I am not going to crank my engine while they're this out of whack, because then I'll just be kissing piston with valves (more than they might have already).
So... can I just remove the cams and align them the right way? I mean, when the cams are removed, all the valves are UP right?!
I can then crank the engine over (by rear-wheel, because the damn alternator nut won't ever come off!).

My idea;

Mind you, all necessary or blocking parts are off already. All fluids are even drained ;).

1. remove CCT
2. remove upper chain guide
3. with the loose chain, remove the cams (along with the attached sprockets). Hold the chain, don't drop it.
4. crank the engine to the FT mark. Check if the OTHER (rear) cilinder has its cams facing downward, so on the oposite stroke from the front (if that makes sense).
5. place the cams back, aligning them properly (upward, outward, aligned). Bolt them down up to spec.
6. place the chain guide and the CCT back (manuals this time), tension the CCT.
7. See what valve-clearances I have and do a compression check

Hope the above makes any sense.
I realise that my valves are probably bent, but I'm not asuming anything. I wish to measure these (the clearance) once the timing is in order. Probably do a compression test too.

Thanks for the advice everyone !

[tony.mon]

Yes, all of that works.
Assuming that you know which cylinder has the cct that HASN'T failed, remove the affected cylinders cams and turn to the correct timing point fit the good one, and then rotate the engine to the correct timing point for the affected cylinder and reinstall the cams.
Then measure clearances, if the broken cylinders Gaps are all too large, pull the head off and repair.

[vivec]

Thanks !
Although it sounded clear as rain in my head, it's simply good to have someone else's view on things.

Asumption is the mother of all f****ps, so best have some extra / alternative views.

[Wicky]

Greetings

Have you contacted Rob de Hoo a fellow VTR riding flatlander who distributes Krieger Manual CCTs ?

https://exhausist.com

https://www.facebook.com/robdehoo

[vivec]

I've eBay'd the CCT's already, but thanks for the tip nonetheless. If the bike lives, I'l be wanting to upgrade and I see Rob can supply all sorts of accessories.

[vivec]

So... on a scale from 1 to 10, how bad is this?

The valve-bucket won't come up when I lift the cams / lobes up...
I'm guessing the valves underneath are bent like straws, but haven't taken the head off. Wanted to check in here first...

[vivec]

By the way, the buckets themselves are not stuck! They move very well. I can pick them out with a light magnet and you can 'turn them' by just moving your finger across. So it's like if the spring won't push them back up while the cams have been lifted off them...

Gawd, I'd hate to get the head off and see the mess ;)

[vivec]

Some other strange thing... bike doesn't want to shift past 4th gear.
So without starting it, it will shift up up up up to 4th, but then it doesn't do any more shifting. It's not stuck, but pulling up the gearlever by foot simply moves it up but no 'click'.. if you know what I mean. Is that normal? Of should I start prying open my gearbox as well... ?!

[VTRDark]

Oh dear.....what a mess. Actually getting the head of is really simple, what will most likely give you some grief is getting the springs compressed to get the collets out and then back in so a spring compressor is required ( extra expense ) then we dont know the state of the valve guides if the valves are that badly damaged. Then you will need a new head gasket ( extra expense ) and possibly some diffrent size shims for getting your valve clearances. (extra expense and ofcourse the valves themselves ) and you may as well change the valve stem oil seals with Orginal Honda Ones Only so more expense You can use pattern part head gasket. It all adds up so you may want to consider getting hold of another head complete with valves and transplant that on instead. The worst part of having to remove the head is getting the exhaust nuts undone. Lets hope these are not siezed and end up snapping. Best to use a nut splitter to get rusted nuts off and replace them. Better to be safe than sorry as removing broken studs is a nightmare.

As for the gear selector they can get a bit stuck when there is no momnetum. You can't exacly rock the bike back and forth because your valves will stop things spinning over. First things first get the head off to assess the damage. Have you got a torque wrench because you will need this for the head bolts. And dont forget the small bolts down inside the camchain tunnel. Stuff some rag down there as you dont want to risk dropping one down inside the engine.

Drain coolant
Undo exhaust mount and drop the exhaust out the way
undo top rad bolts and pull them outwards after removing the hose that runs across the front.
Drop oil cooler and the bracket that holds it to the frame.
Remove cam cover
Remove cct and undo the small coolant hose that connects to the head
Remove both cams with sprockets attchached (don't mix them or the cam caps up) dont worry about the chain dropping down
Remove spark plug
undo the head bolts and the small bolts inside the cam tunnel

IIRC I think that's it so give the head a knock with a rubber mallet to loosen and free it up and you should be able to lift it up and forwards and out from the front and dangle the cam chain over the front of the block

[vivec]

hi @VTRDark,

Thanks a lot for the reply.

When the valves are bent, the bike is down anyway. The expense part was clear from the beginning ;-). It's now just a matter of how much and NOT increase that amount by being dumb or negligent.

Everything else (radiators, hoses, fluids, etc.) is off the bike already and I have pretty much all tools required, except for the tool to load / compress those springs and get valves out. But I've read that it can be manufactured using a large clamp and a lot of patience.

Anyway... the thing that bugs me most are the prices of original Honda parts. Especially since the economic value of the bike is so low these days. Then again, you either like to ride it, or you don't... so it's all relative.
8 Euro's for a single metal shim however... is just criminal.

I'll be removing the head and see if there's any structural damage to the head itself. When the cylinderwall or the valve-seats are damaged it'll be a new head. If not, then I might try to lap a few new valves in myself. My father was in engine revision decades back, so I'll have at least some historic experience to help me .

Would you recommend changing the camCHAINs out? The bike has run 80.000 kilometers and I cannot find any evidence of them being changed ever. They look fine by the naked eye... then again, that's a sore indicator.
Also when the head is off, I'll check the chain guides. There's no way to really inspect those with the head still on.

By the way, the front CCT came out like this:



... so it's a clear story as to the cause of the catastrophy ;).
Replacement manual CCT's are on their way.

[vivec]

I love the smell of napalm in the mornin...







The piston looks pretty clean (grind in there fell in when removing head). No visual damage apart from the carbon.

Next step is to get the valves out and see what exactly needs replacing...

[VTRDark]

It's only the valve stem oils seals that really need to be original Honda parts if your going to change them. There's a couple of thou differance between the inlets and exhaust which you don't get with the pattern part oil seals. You can use a pattern part head gasket (much cheaper) and you can get shims anywhere but you need to measure up first so you know what sizes to get. Cam chains very rarely need changing. They do stretch with age a little but nothing out of the ordinary and I wouldn't worry about the chain guides.

Two bent valves is the norm. Straight forward failure there. That is how the ACCT looks. It's the internal spring that breaks.

viewtopic.php?f=18&t=38226

[vivec]

How would one get the valves out? I mean, the manual describes a specific tool for pressing / pushing down the springs, but those are costs I don't want to make ;).

Found contraptions like this on a Dutch forum.



Have you guys got any genius ideas or contraptions which you used for this job?

[vivec]

plain valve tools aren't that expensive I'm finding out now. However, I believe they're all asuming your valves are still straight...
I'm wondering if they will 'fit' a bent valve.

Also, I tried pushing the spring down manually (something underneath the valve-head) by hand and with a socket on top (no hammers or anything) but it won't even nudge.

[tony.mon]

Just buy the right tool for the job.
You can sell it on to someone on here, there's no shortage of new people logging on and asking how to stop their engine clattering.