9K rpm limit for the VF500. Why?

The 9K limit is interesting. I wonder where this came from? I (try to) stick to it and I have seen plenty of evidence of dropped valves, I do wonder though it we are all being a little conservative. Assuming one knows about the dropped valve thing, then chances are your 500 will be well maintained. If it's well maintained, decent oil, valves clearances in spec etc etc then maybe we should stop worringing about it. The mileage these bikes will cover will be typically very small too. I reckon I am going to forget the self imposed limit and thrash the tits off mine from now on. (I have a spare engine btw..)

 

When I owned my VF500 I had no problems staying under 9k. Hell...I rarely go over 9k on my 4th gen. But with the VF500 I had the extra persuassion not to rev the tits off the bike cause of the Valvetrain problems.

The bike has lots of torque and midrange and easily pulls hard throughout the rev range. To this day, when i ride my old VF500 (my friend owns it now) I'm surprised how little you need to rev it to the limit.

I don't think it's conservative. ...why put the poor bike at risk and beat it up unneccesarily?

If you feel the need to rev the nuts off a bike you ride then you're riding the wrong bike, imo.

 

It's more fun for one. I'm just wondering how the 9K limit came about and why 9K. According to the (very limited ) dyno data I've seen, the engine still makes good power right up to the redline. IMO revving a engine to the redline doesn't qualify as beating it up. It's what they are designed to do or in the case of the 500 perhaps not..

 

You got me there. :tongue:

I think Jamie D mentioned that is what he recommends, and is what he pratices with his 500's.

You're 100% correct. The VF500's do make power up to the Redline...and yes the Engine is designed to make power all the way up there.
But it looks like they (Honda) buggered up somewhere and the Valves take a hike.

The 9K limit is just a guidline pratices by some on this forum....no way is it anything official.

 

There was a VF500 racing series in the UK when the bike was first introduced. (There are clips on Youtube). AFAIK they were pretty stock. Would have been interesting to see if there were valve issues then as it's pretty hard to restrain yourself to a 9K limit when racing:smile:

 

Probably has something to do with valve float at upper rpms due to weak valve springs or a frequency-driven harmonics problem between cams, rockers, springs, and valves.