Hi,

I've been suffering some hesitation with my NC21 (ZH) recently, at high speed and having cleaned out the carbs the hesitation is still present.

I put in four new NGK CR8EH-9 and was wondering what other people use in theirs, I'm aware that the fuel in Japan is different to ours (100 octane) and so would this have an effect spark plugs to use in the UK?

If not the plugs, I was wondering if a dirty ignition pickup could be the cause of the hesitation.

Cheers

Geraint

VFR22B wrote:Hi,

I've been suffering some hesitation with my NC21 (ZH) recently, at high speed and having cleaned out the carbs the hesitation is still present.

I put in four new NGK CR8EH-9 and was wondering what other people use in theirs, I'm aware that the fuel in Japan is different to ours (100 octane) and so would this have an effect spark plugs to use in the UK?

If not the plugs, I was wondering if a dirty ignition pickup could be the cause of the hesitation.

Cheers

Geraint

no not at all.. very few bikes in Japan are designed to use High octane fuel... all VFR400 series bikes are designed to run on 91 octane unleaded fuel, so normal unleaded will be fine for this bike as uk fuel is 95 ron. Japanese regular grade is most often 90 or 91, so slightly less knock resistant than UK regular grade but still fine for a vfr.

C8EH9 are stock plugs but having a resistor plug wont make much difference, i've never had any trouble using htem.

Hesistation at high speed isnt likely to be a plug issue, it could be a dirty pickup but not likely.

Fuel supply / vaccumn tap / vacuum line / fuel tank vent

carb settings / airbox / air filter.

generator / charging system / electrical system.

i would check the above in that order.

Thanks for the suggestions Neo, I shall investigate this weekend.

The bike seems to hesitate especially when I'm at an angle (when cornering) and I could make it hesitate even more by stretching my legs out straight when riding on the motorway - not sure if this would give you a clue as to what the cause of the problem is!


Cheers

Geraint