Inlet valve replacement on front cylinder

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smokerider
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Inlet valve replacement on front cylinder

Post by smokerider »

Hi !
My VTR has been giving a fluffing kind of valve noise for some time, like 3-4000 km. Sadly 2 weeks ago I found out why.
When I came home from a strowl my engine suddenly sounded like a Ford Taunus or Opel Astra with worn cams.
Instinctly I ordered new CCT's, and got to the job when they arrived. As described elsewhere in the forum, it was the front cylinder who had the failing CCT.
The sping inside had not broken, it was just worn and soft, compared to the new part. The inlet valve cam had jumped one tooth, and because of the chain's
lacking tension, this in addition to the one tooth, has caused my inlet valves to touch the piston, and take some damage.
After the repair the engine runs nice at idle speed, but when I rev it, knocking noises appear on the front cylinder, which I suspect to be the noise of bent valves.
If anyone here have had similar experiences, and could confirm my suspicion of the bent valves, this would be helpful, as I haven't ordered replacement parts yet.
My VTR has 53000 kms, would new valves and top head gasket be the only parts needed, or do I have to dig deeper in my wallet and replace more parts when the
cylinder head is on the workbench anyway ?
Thanks Smokerider... :roll:
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benny hedges
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Re: Inlet valve replacement on front cylinder

Post by benny hedges »

the valves will most probably be bent.
possibly also damaged the piston crown.
could be more damage but you wont know without removing the head.
good luck :)

and make sure you time it back properly.....

just one question - why did you buy new honda tensioners when youve proved to yourself they fail...?
You do not have to say anything. But it may harm your defence if you do not mention when posting something which you later rely on in quote. Anything you do say may be ripped to sh*t.
tony.mon
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Re: Inlet valve replacement on front cylinder

Post by tony.mon »

I'd hazard a guess that it's actually bent the exhaust valves, so best not to order parts until it's stripped.

One tooth out doesn't normally allow the valves to touch the piston, so i would have thought that it's moved out by at least two teeth, but there's really no poj nt in just fitting manuals or replacement CCT's and hoping it'll be ok, you need to pull it apart and see.

If you take off the front cam cover you should be able to see how far down in the head the buckets are sitting; they should be roughly equally positioned when the front cylinder is in the correct place to fit the cct.

But you'll have to take the head off, I'm afraid, to be sure.


You'll need an exhaust gasket plus whatever valves need replacing, plus shims to get it back within tolerance once completed and refitted.
It's not falling off, it's an upgrade opportunity.
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sirch345
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Re: Inlet valve replacement on front cylinder

Post by sirch345 »

S/R, You could just try a compression test before stripping it down again.

I hope you used the instructions in this link below for setting the valve timing when you fitted the new CCT's :?:
http://www.vtr1000.org/phpBB3/viewtopic.php?f=31&t=8326

Chris.
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smokerider
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Re: Inlet valve replacement on front cylinder

Post by smokerider »

Hi again,
last night I found out that the valves are OK, there is a problem with fuel for my front cylinder who causes the engine to stop after about 30 sek to 1 min.
At first at idle it runs normally and fine, but after some time the front cylinder wont run.
There has been suggestions put to me that the carburetor tube to the front cylinder might be out of position, or that there is a blocking of fuel 2 the front carb.
Beneath the fuel tank there are 5 hoses, 2 who connects directly to the carbs, 1 overflow, 1 thin tube under the fuel tank that I haven't seen where ends up, and 1 more that goes directly to the tank. The thin tube underneath, and the overflow tube were worn and bad, I will try to replace the tubes, and check the carb connection to the front cylinder.

As for the positioning, yes I have disassembled 3 times to check the cams and the positioning, and there was 1 tooth out of position on intake cam the first time, after that
everything was ok with the timing.
As to why I replaced the CCT's with new Honda parts, this is why the Honda shop assured me that the new parts are OK since the change in 2002, and that I don't like the idea of having to service APE CCT's regularly. (My big hands don't fit very well in these narrow spaces ! :lol: )
Any advice on what could be the reason why my front cylinder runs out of fuel after 30 sek to 1 min would be appreciated !
Thanks Smokerider
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Stratman
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Re: Inlet valve replacement on front cylinder

Post by Stratman »

If you have connected the vacuum hose to the bottom of the petrol tap then it is in the wrong place - it should be on the side. The bottom "lug" does not have anything connected to it.
Two bikes, still only four cylinders!

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Wicky
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Re: Inlet valve replacement on front cylinder

Post by Wicky »

...As to why I replaced the CCT's with new Honda parts, this is why the Honda shop assured me that the new parts are OK since the change in 2002...
Could you get the Honda shop to put that guarantee on OEM CCts in writing as well as promising to rebuild your engine in the event that they fail - which dealers are they?
... I don't like the idea of having to service APE CCT's regularly.
How often do you think manual CCts need adjusting?

P.S. +1 on the vacuum hose
It may be that your whole purpose in life is simply to serve as a warning to others.

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smokerider
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Re: Inlet valve replacement on front cylinder

Post by smokerider »

(Re: Inlet valve replacement on front cylinder

Unread postby Stratman » Thu Aug 04, 2011 9:39 am
If you have connected the vacuum hose to the bottom of the petrol tap then it is in the wrong place - it should be on the side. The bottom "lug" does not have anything connected to it.
Two bikes, still only four cylinders! )

Hi again, my petrol tap has the 2 hoses on each side, and the 4/8 mm hose underneath, as it was before I disassembled anything.
Do you know how this vaccum assisted petrol tap works ? Is it in need of vaccum from both cylinders in order to give petrol to the carb ?
I just bought new hoses which I will change this afternoon. Am beginning to think it might be a vacuum problem, or some dust blocking tube to front carb..........
Any suggestions are appreciated thanks !

PS ! As to the CCT's, they came from davidsilverspares in 6 days, and is a reasonably priced replacement part for the original, I would give them 20000kms, aka 4 years of riding.
Thanks Smokerider
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Kev L
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Re: Inlet valve replacement on front cylinder

Post by Kev L »

The trouble is, smokerider, nobody can give you a guaranteed lifespan for the stock CCT's. They may last 2 weeks or 12 years before the spring gives out and pistons become intimate with valves. You may be lucky, you may not.
Just do a search using the facility in the top right corner of the forum page on CCT failure and you will find plenty of information about the consequences of your course of action. Don't be surprised that a Honda dealer tells you to replace the CCT's with equipment THEY SELL. They are after all in business to make a profit, however they will never back it up by offering to repair damage caused by a failure.
I fitted manuals from Rider on a storm as soon as I got mine, just for reassurance. I haven't had to adjust them as yet and I know Benny of the Hedges has done a significant mileage with very little attention to the CCT's.
I wish you good luck with whatever you decide to do fella but remember you have been warned.

:wave:
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AMCQ46
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Re: Inlet valve replacement on front cylinder

Post by AMCQ46 »

if you like the concept of automatic adjustment [which I do], then fit the stopper mod [look in workshop knowledge base] to the new Honda parts, and you have the best of both worlds. Auto adjust and no bent valves when they fail.

on the vacumn petrol tap, the small vacumn hose from the reat cyl inlet should be fitted to the back of the tap, the fitting on the bottom of the tap is actually a drain, and should not have a hose fitted.
AMcQ
tony.mon
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Re: Inlet valve replacement on front cylinder

Post by tony.mon »

I had standard ones fail after 18 months.

Bent valves.....
It's not falling off, it's an upgrade opportunity.
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smokerider
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Re: Inlet valve replacement on front cylinder

Post by smokerider »

Re: Inlet valve replacement on front cylinder

Quote: Postby AMCQ46 » Thu Aug 04, 2011 1:04 pm
if you like the concept of automatic adjustment [which I do], then fit the stopper mod [look in workshop knowledge base] to the new Honda parts, and you have the best of both worlds. Auto adjust and no bent valves when they fail.

Hi, could you please inform me more about what stopper modification you are referring to ?

By the way my VTR ran like new last night after finishing the CCT job, and the engine has lost the bad noises it had ! :D
Thanks Smokerider
tony.mon
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Re: Inlet valve replacement on front cylinder

Post by tony.mon »

Just search the Workshop section for "stoppoer" and all will be revealed.....
It's not falling off, it's an upgrade opportunity.
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