Engine Knocking noise

Hi all,

I have a VFR750F-k and my engine has developed a bad knocking noise from the top end and I've lost power due to it. It's got the general clutch rattle they are prone to having and I've checked the valve clearance.

At 3-5000rpm the noise is the most extreme but I am riding it very carefully as this noise sounds quite terminal, can anyone help on this? I'd like to know the issue to fix it, although I have ordered another engine as can't afford the time to do an engine rebuild.

 

here's the youtube link of the noise VFR engine knocking - YouTube

 

Ever run her low on oil, maybe the po did ??

Take the bike off the road now, and trace the problem before further damage happens.

 

Sounds an awful lot like the noise my 85 VF1000F made just before I had the timing chain replaced. The engine would make a metallic slapping sound, especially when under load. The bike had about 55,000 km's on it at that point. I took it in to a mechanic at the local Honda dealer and they replaced the timing chain, guides and tensioner assemblies. After that the noise disappeared. Not sure if your bike is having the same problem, but might be worth checking. Not sure what year the VFR had the chain driven cams, versus the gear driven cams.

 

89 would have gear driven cams. I'm with squirrel and say park it now before it stops making any noises at all. Sounds like main bearings. With a spare motor coming would give you lenty of time to fix. May decide against it after you get the parts bill though. I doubt its something simple

 

Sounds to be a conecting rod bearing I think but I could be wrong. Ether way id be pulling my engine and going through it.

 

Have to agree sounds like big end bearing.

 

How many miles on the bike??

From the black paint, missing fairings, the bike looks like a beater, not something well-maintained or cared for.

Bad bearings would be unusual on most VFRs, but that one looks abused.