ptroy
14th February 2014, 18:51
Alrighty, a new noise has started coming from my vfr400.
Its a rattle / clacky type noise, not noticeable at idle. Increases with RPM and I only really notice it when on throttle / engine accelerating. With engine deaccelerating the noise stops.
Dosent make any difference with clutch in or out or in neutral.
When riding it sounds like it is coming from the top end, though with it on the stand it is hard to tell, sounds like from bottom end but depends where you listen it always sounds like its coming from somewhere else. Have gone around listening with a screw driver all over the engine and cannot hear the noise at all through the screwdriver, only time I heard something similar was with the screwdriver on the side of the carbs.
With the bike on the stand and in neutral, the sound seems to be most prominent around 3000rpm, especially if you blip the throttle at idle.
Events leading up to this happening:
Got new tyres, and dropped the bike at about 20kph leaving a stop light turning right (doh, didnt realise how slippery new tyres are, or there was something on the road). No damage appeared to be done other than cosmetic damage to the right hand side fairing. I didnt notice the noise after this, so I dont think its related.
Later on going for a ride I accidently over revved it changing gears where I must of selected neutral between 1st and 2nd. I think it may have seen 16k rpm. I noticed the noise almost straight away after this happened. I rode home very gingerly about 40km and the noise did not get any worse.
When I got back to the workshop and was checking the engine I found the oil was extremely low (bottom of dip stick, must of done more km's than I had realised before checking it).
So my thoughts were maybe damaged big end bearings, or cracked piston.
I have drained the oil and it looks fine, no metallic particles. Removed the sump, nothing suspicious in the sump. Looking up at the bottom of the pistons I cannot see any cracks or such things.
I have removed both side covers and nothing suspicious here either.
Any input on what the noise could be? Where else to look, could it infact be the carbs making the noise?
If it was bearings I would of expected to see metal in the oil, and maybe make the noise more consistently.
Before I strip the engine I want to make sure I have not overlooked anything, I would hate to strip it to find nothing wrong.
Its a rattle / clacky type noise, not noticeable at idle. Increases with RPM and I only really notice it when on throttle / engine accelerating. With engine deaccelerating the noise stops.
Dosent make any difference with clutch in or out or in neutral.
When riding it sounds like it is coming from the top end, though with it on the stand it is hard to tell, sounds like from bottom end but depends where you listen it always sounds like its coming from somewhere else. Have gone around listening with a screw driver all over the engine and cannot hear the noise at all through the screwdriver, only time I heard something similar was with the screwdriver on the side of the carbs.
With the bike on the stand and in neutral, the sound seems to be most prominent around 3000rpm, especially if you blip the throttle at idle.
Events leading up to this happening:
Got new tyres, and dropped the bike at about 20kph leaving a stop light turning right (doh, didnt realise how slippery new tyres are, or there was something on the road). No damage appeared to be done other than cosmetic damage to the right hand side fairing. I didnt notice the noise after this, so I dont think its related.
Later on going for a ride I accidently over revved it changing gears where I must of selected neutral between 1st and 2nd. I think it may have seen 16k rpm. I noticed the noise almost straight away after this happened. I rode home very gingerly about 40km and the noise did not get any worse.
When I got back to the workshop and was checking the engine I found the oil was extremely low (bottom of dip stick, must of done more km's than I had realised before checking it).
So my thoughts were maybe damaged big end bearings, or cracked piston.
I have drained the oil and it looks fine, no metallic particles. Removed the sump, nothing suspicious in the sump. Looking up at the bottom of the pistons I cannot see any cracks or such things.
I have removed both side covers and nothing suspicious here either.
Any input on what the noise could be? Where else to look, could it infact be the carbs making the noise?
If it was bearings I would of expected to see metal in the oil, and maybe make the noise more consistently.
Before I strip the engine I want to make sure I have not overlooked anything, I would hate to strip it to find nothing wrong.