First, thanks to Kiffsta and Glen for being absolute legends and helping me with some parts for both my gsxr250 and fzr250. I have been gifted an FZR250 for $300 that I am putting back together. Having serviced the carbs it actually started really easily and runs on all cylinders. However, I have a knock that I don't like the sound of. Can any of you Yam experts give me any ideas. Is there hope that once its warmed up a few times oil flow will quieten it or is that just wishful thinking? Are there seals that may have dried up or lines that could be clogged? Having spoken to a very well informed and trusted source of info it has been suggested that possibilities include: starved bearings in 1 and 4 first gear knock clutch basket rubbers dry Any further opinions regarding recommissioning an FZR that's been stood for several years is greatly appreciated.
Can you get a clear video with good audio? I had a 3LN6/7 motor with a rod knock. Giving it the italian tune up did not fix it (younger and less wise). Pulled apart to find a spun rod bearing on #3, someone had installed the rod backwards with the rod cap the correct way. If the throttle balance is out by quite a bit, you can get knocking/rattling coming from primary drive gear and gearbox, but get us a video first and we'll go from there.
That sounds "ordinary" Did u change the oil and filter before the initial start up? Was there any stray engine components in the old filter?
Hey, Yes I did but I admit I didn't look into the filter too closely. I'll go find it and take a better look. When you say 'ordinary' I assume that is sarcasm!
Sorry mate, this is all a bit cryptic for me. The engine obviously has an issue, in your opinion should I be running it at all? Is it catastrophic do you think to the point of a total rebuild?
Looking into the old filter will give u an idea of whats going "Engine" diagnosis isnt my expertise so maybe a few 'experts' in that field here can give an opinion or advise what the next move should be ? @Murdo @maelstrom @Linkin @Andych
Sorry, never found videos of engine noises to be useful for anything. My two cents is strip the engine and fix it.
You could certainly try balancing the carbies first... they do present with strange knocks, ticks etc unless they are all pretty close in balance. Check the timing chain tensioner as well but in the end... the only way you are going to know what you have is to do as @maelstrom has siad and pull it down...
Thanks for the help so far. I'm pretty sure the carbs are good but will recheck their balance first. Having listened to the motor with the screwdriver stethoscope method the real noise is around the stator/bottom of cylinder 4. It has been down on the right hand side so I'll pop the cover off of the stator to have a dig in there. Are components available for these things? if I'm going into pulling it down I will do it completely. Can I get gaskets/rings/valve seals/bearings etc? Thanks
There are quite a few sounds happening in that video. For one I can hear the cam chain rattling away, so it will need a new one (replace the tensioner springs also). Try nipping up the exhaust headers, it does sound like it has exhaust leaks. Just don't bend the flanges. New exhaust gaskets would help. Being honest if you want to fix it for a long time and not a short while, an engine removal and tear down would be the way to go, that way you can put all new bits in and it will be much happier.
The camera microphone is very sensitive - try the cardboard tube method, as it is idling it could also be the primary driven gear for reasons that we discussed - try pulling in the clutch and putting it into gear with the idle speed set
Hey mate, I pulled in the clutch and it definitely quietened one if the knocks. It also definitely smooths out when the engine revs up to speed a bit. I haven't looked into the work involved in repair or exchange of the primary gear. I assume its pretty exensive?
Primary gear is on the back of the clutch basket, they come as one unit. However when you disengage the clutch, the output shaft on the gearbox stops receiving drive (it will turn even in neutral due to clutch drag or a stuck clutch) Excessive imbalance of the throttlebodies/carbs can cause uneven power pulses, meaning uneven accelerations, and that's why you can get knocking/rattling from it.
@ruckusman .... u are in my expert list but for some reason I left u off .... too much multitasking on my behalf while posting And @maelstrom , I knew what your answer was going to be but didnt want u to feel left out
Thanks so much Fellas I also know that the only real solution is a tear down and rebuild, I guess was just hoping one of you knowledgeable fellows would say that there was a common cause and simple cure before I begin the task. Back to one of my questions: are the parts needed for a rebuild still available?