another nc30 crank!

[geoffro]

Hello guys, I have just bought my first 400 VFR and this will become a track/race bike in sunny South Africa.
I was enticed into buying this bike by a friend who is a bike mechanic as they want to increase the 400 class at local events. After paying for the bike(very little luckily,it has a bad crank knock), I decided to read up a little on this bike. I was very impressed that it is well loved and respected by many. Also told its bullet proof....
Which leads me to next question... I find after research that (including my bike mechanic friend) that these bikes do not "respond" well to crank rebuilds...I thought I read they are bulletproof!! I need to find another motor or crank. What if that one also does not last long? Has anyone succeeded in buying new bearings/having crank cut etc? (I am an auto mechanic so reasonably "savvy" with engines/and bikes).
Any advice appreciated chaps,thanks

[Neosophist]

Hello guys, I have just bought my first 400 VFR and this will become a track/race bike in sunny South Africa.
I was enticed into buying this bike by a friend who is a bike mechanic as they want to increase the 400 class at local events. After paying for the bike(very little luckily,it has a bad crank knock), I decided to read up a little on this bike. I was very impressed that it is well loved and respected by many. Also told its bullet proof....
Which leads me to next question... I find after research that (including my bike mechanic friend) that these bikes do not "respond" well to crank rebuilds...I thought I read they are bulletproof!! I need to find another motor or crank. What if that one also does not last long? Has anyone succeeded in buying new bearings/having crank cut etc? (I am an auto mechanic so reasonably "savvy" with engines/and bikes).
Any advice appreciated chaps,thanks

They are bullet proof, not idiot proof.

No disrespect aimed at you personally, but many of the bikes and horror stories about mechanics on these bikes that have been posted up on here over the years from south africa is really shocking.

It is often cheaper to replace the engine with a known good one, as you read, they are bullet proof, all you need to do is change the oil regularly and check the valve clearences they will last for a long time.

Sounds like it has been abused.

It is knock coming from the big end though right, not clutch rattle or anything else?

[geoffro]

HAHA Neo!! I fully understand not "idiot proof"!!
No offense taken many call themselves "mechanics" but just own some tools... I would like to think I dont fall into this catagory(with official qualification etc)
As you probably know it is very difficult to figure out weather an engine is a "known good one". We often dont have a huge choice in engines for sale.I am weary of buying one that "seems" looked after to have another crank go bad... But I suppose its a chance you got to take.
I fully agree on the oil/valves maintenance and no "rev limiter" etc. I will double check on the noise thanks for input my friend

[Neosophist]

HAHA Neo!! I fully understand not "idiot proof"!!
No offense taken many call themselves "mechanics" but just own some tools... I would like to think I dont fall into this catagory(with official qualification etc)
As you probably know it is very difficult to figure out weather an engine is a "known good one". We often dont have a huge choice in engines for sale.I am weary of buying one that "seems" looked after to have another crank go bad... But I suppose its a chance you got to take.
I fully agree on the oil/valves maintenance and no "rev limiter" etc. I will double check on the noise thanks for input my friend

You can bounce it off the rev limiter, its there to stop over-revving :)

Unless your downshifting then that is a different issue.

Anyhow.. yes find out where the knocking is coming from, does it go away if the clutch is pulled in, stupid things like is the amount of oil ok, nothing is loose right (exhaust colars)

If it really is big-ends then easiest way I can think is to find someone reputable to sell you an engine.

[geoffro]

thanks Neo, will look into all those. Have not even seen the bike yet, only info was from my friend. I know that sounds silly but paid less than what the rolling chassis is worth!! I can put a buck or two into this baby.