3700-4000 rpm occasionally running rough

Gidday,

I ride a 2000 VFR - done 48,000km. Owned it for only 6 months. I have an annoying problem with the bike that bike shops don't seem able to resolve.

Sometimes (for 1 or 2 km in every 70km or so) if I am accelerating slowly or cruising slowly in 3rd or 4th gear at 3700 - 4000rpm the engine will suddenly start running roughly, like it is starved of fuel or something. It will come right as soon as you get on the gas and get above 4000 rpm. It never happens if I am accelerating hard through the same revsl. only when cruising or taking it easy.

The strange thing is that it doesn't do it all the time. Both local bike shops (Sydney Australia) reckoned it was cos I had an after-market exhaust fitted (Remus Grand Prix) - the solution: get a power commander and expensive tune up or go back the the standard exhaust. I went with the latter and picked up a pipe on ebay hoping that might fix the problem: it made no difference at all!! Grrr.....!

Anyone had this problem or any ideas on what the problem (and solution!) might be??

All thoughts welcome.

Cheers,

pete norton

 

Just about every VFR like yours (5th gen) is rough and barely has any power below 4K rpm. I wouldn't worry about it and instead keep your bike above 4K rpm.

 

That's one approach!

Thanks for the reply.

I have learned to largely ride around the the problem by keeping revs up BUT I'm just one of those riders who likes to have the whole operation running sweetly so will not be happy till I have it sorted.

Cheers,

pete

 

I agree with Joey. The 5th generation VFR likes to run above 4k. Most folks ride theirs between 5-6k when cruising. It runs the smoothest in this range. I don't think it is a flaw, just a characteristic.

 

Thanks for that

 

Remembering the VFR has a 12K redline the Gen 5 prefers to be above 4 or even 5K. Having said that have found no problem with mine 3rd gear bimbling around the Suburbs with gentle throttle in the 3.6k to 4k range on my '99 although my previous Gen 6 hated it. Could be related to the Gen 5 Mk 2 closed loop exhaust system (?) , if so O2 sensor removal with PC2 may be required to fix that.

If you want a good VFR mechanic to service your bike can point you to mine in the Penrith area or if in the North Shore have heard from other OzVFRers " Lloyd Penn " Artarmon is the man to see for VFRs.

 

I have actually found that I get better mileage running in traffic at 5k vs. 4k or less. Who woulda thunk.

 

Thanks for useful reply.

I'm in Fairfield so would appreciate contact details for VFR savvy mechanic in Penrith.

pete norton