Morning all, I bought a 1997 Triumph Thunderbird 900 at the end of last summer after a 10 year break from sports bikes. Great decision. Love the sound, torque, kerb appeal and flickability of this bike. But, unless I am going mad, I think it is getting rattlier. At first I suspected the Alternator bolt issue but it does sound like its coming from there. I now suspect a loose cam chain. So, can the wise elders help me answer these questions please... Does this sound like a loose cam chain or is this just the noise this engine makes? https://youtube.com/shorts/SG_djmU-K8c?feature=share Is it a DIY job? Im reasonably competent... ish. Where can I get a Cam Chain Tensioner? Thank you all S
Those engines tend to be noisy, even agricultural , it does sound louder than my Sprint did tho. If you pull the clutch lever with engine running does the sound go away? If not it is probably the clutch basket. If you have engine running and turn the headlights on full does the sound go away? If so it is either the alternator cush drive or the broken/loose alternator bolt. I'm not sure but think on your engine the bolt is fixed by splines somehow and the nut is on other side of the engine so you may have to remove opposite side cover to check. Sprint mfg, triumphparts.co.uk sell new camchain adjuster springs , yours may be worn and undersize. I've never done the jobs myself so can't help more.
Hi, Ive just been out to check. If I pull in the clutch lever there is no change in sound. When I turn the headlights on it does not change either. I've read about the alternator issue and, while Ive not had it apart yet, I cannot hear a localised rattle. Ive also been googling Tbirds on YouTube and mine definitely sounds more agricultural. Change of oil made no difference. Currently Im thinking its a worn cam chain or tensioner. I have ordered a new cam chain tensioner spring and am trying to work out if I can just pull out the tensioner without having to do all the TDC fiddly bits.
Stu9000 Yes i go for the tensioner. What are the miles on the bike and make sure the self adjuster hasn't just stuck. But i think you can change by just loosing things of. Joe.
This is what I was hoping you were going to say! 28k miles. 3 owners. Tidy bike. New spring ordered. Just to double check... I can remove the central bolt without messing up the timing mechanism. Do I just refit the bolt with the new spring and let it reset itself? Thanks again for the advice. S
I removed the central bolt in the cam chain tensioner. 71mm long. so, I believe, not obviously old or compressed. I even put a couple of washers on to create more push but it didn't make a bit of difference. Took em straight off again. So what does this mean? I contacted the old owner. He agrees it's definitely got more of a rattle. If a new spring isn't going to sort it could it be the cam chain needs replacing? Or has the tensioning system been damaged? Or is it something else? It's spoiling my enjoyment of the bike now. Worried something is wrong. Sounds bad. Maybe I should take it into a triumph garage.
I use one of these cheap stethoscope things to pinpoint engine noise, like this one: https://www.amazon.com/Powerbuilt-6...=Automotive+Stethoscope&qid=1651601403&sr=8-4 I suppose you could improvise with a length of steel rod, pressing your ear to one end and move the other end around various parts of the engine: head, generator, bottom end, exhaust etc. It's hard to proceed when you don't know where the noise is coming from. Good luck with it.
Stu9000 Trick i have tried before is take the cam chain tensioner nut of and put a small washer or something to tension it a little more. Then reverse the crank a couple of times and see if it quietens could be just a sticky tensioner. Let us all know how it goes. Joe
Wouldn't think it was exhaust leaking or valves. The exhaust would make a hissing or chuffing sound and probably pop on over run and the valves tend to get tighter with wear, not looser. Just wonder if it's possible to take the cam chain spring out and push the adjuster blade to put more pressure on it, could be stuck, tho I have heard of them breaking up. Was it hard to get the spring back in? I believe it takes some force so if it was easy I would guess there is something broken in there. How does it run generally, is it smooth and responsive? Carbs could need syncing. Is everything tight, could be loose exhaust mounting, engine mounting etc. I would give all bolts a once over.
Thanks for the replies. I tried to hear with a length of wood pressed to the cheek bone. Does not seem to be the alternator or clutch areas. The clattering noise seemed to be coming from the top of the engine. The top of the middle exhaust tube was the most significant but it's hard to be specific. When I took the cam tensioner spring out it was reasonably hard to push back in. Appropriately hard I would guess. Joe, I will try your suggestion. I did try adding three washers to increase the pressing force of the spring. No change. But I will try again, rocking it back in gear. Springdave, I was also worried the guides for the chain had eaten themselves or something. But feeling pressure when refitting the bolt maybe discounts that..?I 'll try pushing on whatever is down that hole with a screwdriver to see if it's stuck. Exhausts seemed not to be leaking. Tried soapy water and no bubbles. Carbs? Could be. Would they contribute to the rattle/clatter noise? Rubbers looked a bit cracked. The bike was popping on over run excessively even for a tbird when I first got it but I've been dosing with the yellow carb cleaner fuel additive and that seems to have helped a lot. I know outboard 2 stroke carbs so I reckon I could sort them out. It just doesn't sound like that though, but I'm a newbie so who knows! I'll take the tank off again and go round to check everything is tight. That's a good suggestion. The engine starts well. Pulls strongly. The bike has been a joy to ride. But the noise has got worse I think. It sounds more agricultural than other 900s on YouTube. I'm thinking of putting it into a garage. Carl Rosner seem to have a good rep. Or maybe even a triumph dealer. But this could get expensive. Thanks again. S
I just had a chat with the guys at Triumph West London. They were happy to talk through the issue at length even though it was 530. Extremely knowledgeable and not remotely patronizing. I was grateful for the time. I'm told if it does not go quiet when the lights are switched on (alternator issue) then there is a good chance it is the bolt that goes all the way through the engine to the clutch basket. I think he was saying the end shears off and the bolt just rattles around. Ill try putting it into first gear and dragging the clutch to see if it goes quiet. Then, at some point, Ill open it up and have a look for a polished bolt head. Ill also give the tensioner blade a good poke, and try rocking it as suggested. I will also generally eyeball any bolts around the engine to look for anything loose.
Ok, so the plot thickens. Having watched a ton of YouTube vids I convinced myself this is a cct issue. New spring arrived. It was longer than the existing one so I was hopeful. But the new spring did nothing to improve the rattle. With the spring out i tried to push a screwdriver in to see if i could help it along to a click, but no joy. I backed off the cct housing (two bolts) a few turns to see if that would allow it to click (I know, bodge territory). In doing so I realised the spring was not pushing back on the housing. So i took the housing off completely to look at the mechanism. It IS at full extension. The spring is doing nothing because it cannot extend the plunger any further. So, new chain or guides/pads required, or both. Few questions... Triumph dealer says they cannot get me in until June! I am at the point where I am happy to spend money but if I am without a bike for a month it might be worth doing it myself. Has anyone done this job? The other issue is the bike made a bit of a clonk when I took the housing out. Im guessing that is the tensioner guide pushing back. Running the bike up and down the road was ok. It sounds ok but wont idle properly. Jumped a tooth? Not bad enough to bend valves I understand but not sure I can ride it daily. So I am closer to solving the problem but potentially without a bike for a month. Bah!
Just to finish this off... It was the cam chain. 27k miles. Replaced for £500 and sounds a LOT better. Something to be aware of (I'm guessing many of you already will be)... The inner 'bolt' part of the cam chain tensioner can be removed without worrying the cam chain might slip. But I pushed my luck and removed the outer housing. There was a distinct clonk. When I reassembled it the bike would not idle, so I know Id made a mistake. I rode it very gently to the garage. They later told me it was 4 teeth out. I got away with it, just, and learned a lot. But it could easily have been an expensive mistake.
Finally got round to recording how she sounds after the cam chain fix... This is how she sounded before ...
