CCTs - let this be a warning to you all...

[bandsawman]

Don't drop the bollock I did...

I've been meaning to get round to sorting out my CCT's since I got my Firestorm nearly 2 years ago - but kept putting it off.
I think I was deluding myself that if one were to go, it would let me know by starting to rattle and then get gradually worse.
Wrong!!!

The first I knew of it when it happened (and, let's face it, I knew it eventually would) was the sound of the piston hitting the valves - I must say that I was shocked at just how loud that sickening noise was! I'm still having nightmares about it now...

The result? Well I was extremely lucky - I only got 3 bent valves, 2 cracked valve guides and slight scarring to the piston surface.
But it's been a surprisingly big job reaching this stripped down stage - fortunately I've been able to tackle it myself, but imagine the labour costs if I'd had to take it in to a dealership?! But it could've been much worse - I could've had a valve snap off - which (I've read) can result in an engine write-off. Also, I could've been stranded miles from home.

I priced up the parts to repair the head, but it was nearing £150 and it's quite a tricky job to replace the valve guides (which I'd decided was beyond my capabilities, so would have to pay labour on getting it done). Fortunately, this forum saved me - well, Tony.mon to be exact - he offered me a replacement head - nice one fellah

If only I'd done the stopper mod sooner, I could've saved all this heartache and it would've cost me nowt!

[tony.mon]

If a valve snaps off It's a much bigger job, because the piston is trying to shove the valve through the head.
That will wreck the piston, but even then you have to split the cases because the pressure on the big ends and mains means that they will be shot.
But you'd need to split the cases to get the piston out anyway, and while you're there you might as well replace all the shells.

(yes, I know it's possible to go in from underneath; through the sump.
But you need to take the oil pump out to get access, and to do that the clutch has to come off- by that time you might as well bite the bullet and drop the engine out- at least then you're working at workbench height instead of bending over the bike all the time.
And if you put the engine on a £40 engine stand from Machine Mart it's pretty straightforward to split it and rebuild).

Mind you, then you'll start thinking "I might just as well put high compression pistons in while I'm buying pistons" and that's how I started......

So I'll second the warning, even though I make a few bob fixing them up sometimes I'd rather you don't have to go through this experience.

[benny hedges]

bent valves

pfffft.

take a lesson from the legendary pops yoshimura....

http://www.yoshimura-rd.com/t-company_history.aspx?v=co

after an engine failure in 1974, he stripped the top end and straightened the bent valves by eye and reassembled the engine to finish the race.
sheer wizardry

bad luck with your cct mate, good to hear it's on the mend

[sirch345]

A good post BSM Sorry for you, but take notice any of you who are thinking about doing CCT mod's, get them done

Chris.

[sgoaty]

I put the manuals on today as im always paranoid about these things. Its a good job I did as my front one didnt have the metal end piece on it

Was a bit of a faff getting the tension right i did them as tight as I could with my fingers and it started to whine once it warmed up. So I backed them off a fair bit and nipped the nuts up. theres no rattle or whine now so hopefully its OK.

[simo]

I put the manuals on today as im always paranoid about these things. Its a good job I did as my front one didnt have the metal end piece on it

Was a bit of a faff getting the tension right i did them as tight as I could with my fingers and it started to whine once it warmed up. So I backed them off a fair bit and nipped the nuts up. theres no rattle or whine now so hopefully its OK.

I've got a pair of cct's to go into my sons storm in the next few weeks and have wondered about getting the tension correct. Your method is what i had in mind sgoaty.Do you agree Sirch?

[benny hedges]

you will already have at least one cam cover off (hopefully!)
stuff a rag down the chain tunnel, remove the centre guide and feel the tension in the chain.
there shouldnt be any.
you will think it is too loose but it isnt.
there should be a good 10mm of play in the chain.
the bike wont be noisy with 10mm play and it wont jump the cogs.
set both ccts up the same and you wont be far wrong.

dont forget thread locking compound on the centre guide bolts - and recommend you put some on the tensioner bolt too, just to be safe.

[sirch345]

I put the manuals on today as im always paranoid about these things. Its a good job I did as my front one didnt have the metal end piece on it

Was a bit of a faff getting the tension right i did them as tight as I could with my fingers and it started to whine once it warmed up. So I backed them off a fair bit and nipped the nuts up. theres no rattle or whine now so hopefully its OK.

I've got a pair of cct's to go into my sons storm in the next few weeks and have wondered about getting the tension correct. Your method is what i had in mind sgoaty.Do you agree Sirch?

Simo, that sounds reasonable to me. What I think is a good idea is to lock the original CCT off as it is using a locking key (the Haynes manual shows you how to make one of these), but first set the piston for the cylinder you're working on at TDC on the compression stroke (have a read of this to see how that's done:- http://www.vtr1000.org/phpBB3/viewtopic.php?f=31&t=8326 ) then lock off and remove the CCT. With it locked in position you can then measure the distance from the plunger head to the flange (mating surface of the CCT). Next transfer that measurement to the manual tensioner so you have the same distance from the plunger head to the flange, then lock it off in that position with it's locking nut and fit to the engine. Providing this is done correctly you'll safely be able to start the bike and from there you can do the fine adjustments by ear.

As with any work being done involving the valve timing, always turn the engine over a few full turns (ANTI-CLOCKWISE) first, before pressing the starter button.

Chris.

[simo]

Thanks fellas for that advice,it answers alot of questions on the adjustment.

[sirch345]

Thanks fellas for that advice,it answers alot of questions on the adjustment.

No problem Simo, having re-read of what I had written (after checking I got it right this morning ) I've just altered it slightly so it's a little clearer to understand,

Chris.

[tony.mon]

Your write-up in Workshop is spot-on, Chris; I get people on workshop days to read it out and use it as a checklist when setting cam timing or fitting CCT's.
Thanks from all of us