My GSX250 has come back from being tuned but found this sound developed after a few hours of road riding. Just need confirmation that this is my timing chain or perhaps a valve knocking against a piston? Perhaps I need a new chain and a new tensioner? Ben
id check the cam chain to make sure it hasn't skipped a tooth. if the cam chain and valves are all good and it still sounds like that, id have a look at the pistons, make sure the rings are ok and that you're not getting any piston slap
It certainly sounds like its skipped a tooth. I might open it back up. It's the second time its done this in 3 months. I think I might replace the tensioner because it doesn't seem to be keeping the chain tight any more. How frustrating. Do you think its worth getting a new chain? I'll have to take the entire top end off to change it wont I
No idea. I'll leave that to the experts. I thought you had a few issues with the cam chain previously. Was it all repaired correctly then? Does this mean that you have your Keihin CR carbies all sorted?
if this is a common issue for you then its not unlikely your chain is a little stretched/warped. Cam chains aren't usually expensive at all, and inevitably need replacing at some point on an old bike, so if you find a good deal on one i'd just go for it
Mechanic fixe the timing chain issues last time, said it had skipped 3 teeth but fixed it and adjusted the tensioner. CR Specials are being sold. 31mm too big for my bike even with a 180 main jet, 29mm's not sold in a pair for some stupid ******* reason. Unhappy but glad the bike runs on its stockies at the moment. Yes I can get one from Japan for $80 it just means I'll have to open up the whole engine though right? True I reckon its stretched, and the old tensioner needs replacing too I'd say. Neither is doing the job anymore
Definitely sounds like the cam chain is stretched. I'd get a new one and a new tensioner. You should be able to break the old chain, join the new one onto it, rotate crank and feed the new chain through, remove old chain and join the new one. Replace camshafts and tensioner, rotate engine by hand to check timing.
Sounds like chain to me, but hard to confirm through a video. As Linkin said, feed new chain through and old one out. Should not have to remove head.
Sounds like it's going alright apart from the carbies/airbox so it probably hasn't skipped a tooth but if that's the chain it might soon, chains shouldn't stretch that quickly. If a pro has set the tension & it's become that rattly in such a short time then maybe there's another reason. Maybe the guides are shot or moving or something. I'd be taking the head off & start again with new parts & check the whole assembly while your in there, no good having something that looks great it has to be reliable as well.
