hi,i need help with a knocking sound that is coming from the motor-only when hot,mostly evident on the overrun (when coming back down),with no load...no knock if under load (holding front brake in first gear) does not affect riding, no vibration.engine clutch and gearbox seem smooth,just this knocking sound...deep knock in the clutch area of the motor,has only done 15000 miles-2004 model ,I have changed the oil and filter-no metal chips or flakes,the knocking is evident in neutral/stationary and no knock when moving or under load (chain and sprockets are new)..as it's a knock more than a rattle I don't think the camchain or tensioner are the problem, it's more of a fast clunk than a chain rattle--I could be wrong though--the knock is only there at 85 degrees and above (operating temp) and is only noticable on the spooling down from 3000 to 1500 revs at a standstill in neutral,it sounds like big end knocking (deep pitch,not rattle) but I thought that would be more evident under load,this seems to be the opposite...any help would be greatly appreciated
So it is mechanical knock linked to the bike decelarating. There is chassis and components movement. the engine movest on acceleration & de-celeration (even at stand still). So I would check all the engine mounting nuts & bolts specially if there are rubber grommets/ washer involved the could be perished. Also check all the locking washers (if there are any).
Been on holiday, got back friday, only just seen the post , sorry....no it's an internal engine noise like a tapping inside the clutch case, only when hot and can be heard at standstill on the overrun, but sounds like its coming from behind the clutch (if that makes any sense).....Thanks for your response though...
I thought cam chain tensioner, but could it sound like a knock not a rattle?,,,,,and no,no change when you pull the clutch in
WTF? This thread is a month old now. Why haven't you just taken it to a dealer? It could be something serious!!
It's off the road at the moment, and I was only asking if someone had come across this problem before..and I've been away (4th post up) and have been to a dealer (no noises until it gets hot..they think it may be camchain,but did not make a noise whilst it was there)...and it was june before I had any replies.
Understand that, Hawk. But I am really concerned that there might be something serious. This could easily be crankshaft/big end problems because it seems as if you have ruled out most other potential faults. Cheers!!
Went back to the honda dealers today.....the mechanic took the bike out for a good ride and got it really hot, and ...no noise whatsoever!.He reckons that it can't be anything seriuos as big ends or main bearings woulkd not "heal themselves"...he thinks that maybe the tensioner was letting go at temp, or between tension clicks, which may now have settled...just have to hope that it doesn't come back
Good news, Hawk. Now you can go flying - woops, sorry - riding around the 'A' roads for a weekend blast!
MOT,d whilst at the dealers for inspection,new camchain tensioner on order (just in case), so back on the road now...(sp "serious" on last thread)
I wonder if the cam chain itself can strech like the drive chain. Hope it all gets sorted out. TBH 15000 miles is nothing for these motors. BTW did you try running a higher viscocity oil; something like 10w50?
Yes, it does. That's why they have tensioners. Back in the olden days (70s), the camchains of CB250 and CB350 would generate a horrendous rattle. the 12 inches of chain would sometimes stretch at least one quarter of an inch.
It only seemed to make a noise above 106 degrees (really hot), I have since found a coolant leak from a pinhole in the radiator which could make it heat up too quickly and run above normal operating temp......I spoke to the mechanic yesterday and the hottest he got it up to was 95ish (not hot enough) so no noise was evident.... I plan to replace the radiator and he'll give it another go
The tensioner for a chain may not be spring loaded in which case it would not compensate for the strech. That it what the mechanic said to me about my car engine which has chain drive for cam
That is fair enough if you want to adopt an argumentative stance. Here though, in this thread, I was responding to @hawk05 's dilemma with his 2004 Blade which does have a tensioner of the spring-loaded type along which the cam chain will run along a neoprene face. Some of these tensioners are manually adjusted (Blades - RHS, rear of motor) whereas others will be 'self-adjusting' under a hydraulically pressurised piston against the tensioner runner.
