Bent valves.

[Yorkie boy]

Hi all, first post from a Refugee in Lancashire. New to Firestorms and the Forum. Mine ( a 1997, 24k miler) suddenly sounded like a bag of marbles had been dropped in her, was cruising gently at 3000revs at the time. From what I gather, chances are that the cct's have gone and I've probably bent some valves - but the Haynes manual basically advises that any valve work is left to the experts with spring compressors, and I'm no expert and don't have a spring compressor. I'll be changing the ccts (stable door and bolting horse!) but is there any way for a novice to assess what damage has been done and how many valves I may need. Grateful for any help/advice.
Cheers.

[Kev L]

Welcome to the club mate. Sorry it's in these circumstances. I would only use the Haynes for guidance on torque settings and general info. Search on here for a number of guides to help you through your current predicament, also download the factory manual through the link on here. Good luck.

[monkeymatt]

To be honest it's relatively easy to unbolt the cylinder head etc assuming damage has been done .
Mine had all 4 valves bent in the front cylinder a few months ago.
And took advantage of stripping the engine down , cleaning internals and replacing parts .cost me approx 300 pound per cylinder but well worth it .
I found the Haynes manual useful for very few articles but found the manuals on here more realistic.. and I looked at the situation to gain a better knowledge of the bike engine. If you were going to attempt a repair yourself just take your time with plenty of photos check and recheck .
Shop prices for a rebuild would almost certainly make the repair "uneconomic"

[Yorkie boy]

Cheers mate, I've had too much fun already to give her up as "uneconomical". Happy to take my time and get her back on the road, with a pair of new ccts's.

[Jscobey]

While if you bent valves you need far more than CCTs. Its easy enough to pull the headers and see if the valves are straight. Then pull the carbs and do the same thing. Not definitive answers but an easy check. If the damage is worse than just bent valves like piston fragments bouncing around in the cylinder, you'll need a hone to oversize or if its bad enough than you'll need a new motor

[VTRDark]

First determine if you have any bent valves or not. There is a slim chance that you may have got away without any damage at all apart from a failed tensioner. It's really no biggie to remove the cylinder head though for the cost of a head gasket if needs be.

Start with reading the following http://www.vtr1000.org/phpBB3/viewtopic ... 31&t=28583 and get your head around the timing. DO NOT FOLLOW THE HAYNES FOR TIMING IT IS WRONG Then by removing the cam cover do a visual inspection of things. Is the cam chain slack, has it jumped teeth and if so by how many, can you turn the engine over my hand at the crank? Do not try starting the bike until you know for sure or this will cause further damage.

(:-})

[sirch345]

First of all check the front CCT with a small flat blade screwdriver. Remove the end bolt on the CCT and insert the screwdriver so that it drops down into the slot in the worm. Turning it clockwise a little (no more than one complete turn, less would be better) you should feel some resistance, and if you slacken your grip on the screwdriver, providing the CCT has not failed it will turn the screwdriver back. If you can feel no resistance, and the screwdriver doesn't try to turn when you slacken your grip on it, that's a pretty good indication the CCT has failed.

On a standard CCT, at around 3,000rpm is where the tension changes as the engine goes up an down the rev range, so unfortunately it probably is a CCT failure, and more than likely the front cylinder. Checking the valve clearances will give you an idea if you have any bent valves.

As Cybercarl says, do not try to start the bike, as you could cause more damage

Chris.

[adewhitmarsh]

Hi, I can help if you need manual ccts & fitting details. Cheers Ade

[Yorkie boy]

Thanks all, really helpful and reassuring, appreciate the topic-link and the Haynes manual warning! Will take the plunge this weekend and start stripping her down, will let you know how I get on. Still planning to enjoy a few more miles this year before the snow falls.

[VTRDark]

Oh.... and I should add if you meet any resistance at all if turning the engine over at the crank/generator cover then stop, don't try to force it. It's normal to feel some slight resistance as you come around onto the compression stroke but this will be a fluid movement and wont suddenly come to a halt.

(:-})

[tony.mon]

When you find that you have bent two inlet valves on the front cylinder, you can hit ebay for a cheap rear head and strip the valves off that to replace yours. All you need is a spring compressor and a cheap £3 valve grinding stick and paste from halfords.

If it's only a bag of marbles that is usually the extent of the problem, anything more like dropping a toolbox full of spanners into a cement mixer is a valve dropping.

[adewhitmarsh]

[Yorkie boy]

Well......it was all going smoothly. Link provided by Cybercarl made it all fairly straight forward and stripped everything down with no problems. However, when turning the crankshaft end bolt ahead of removing the ccts it feels like it's locked out. the first few turns were accompanied by a regular clicking noise and then nothing but a lot of resistance. Listening to Cybercarl's advice I haven't forced it but I'm stuck with how to sort the timing and get TDC.

Any suggestions on how best to proceed would be well received - kettle on, garage door shut (for now) !!

Stu

[adewhitmarsh]

Did you have 5-7mm of movement on cam chain between the cams, when the manuals are fitted ??

[VTRDark]

Yorkie It'S sounding like you have hit valves, so most likely have couple bent that have not retracted. Sorry I shall post more detail later when I get to a proper keyboard.

(:-})