Hey all,
My RVF has developed a slight missfire above 90ish km/hr or in really windy conditions. Only stutters for a short second then revs cleanly again. Once given more throttle, it will tend to rev cleanly, if held at partial throttle will just continue to sputter. Doesnt backfire at all. If at 110 on the highway it will need about half throttle to rev cleanly again.

Recently changed spark plugs, checked all the connectors Infront of the airbox for damage/melting, and that there was no airbox obstructions.

After acquiring some old documents for the bike, i noticed it has been tuned with #130 jets (these seem very large?). The bike has a full tyga system, and standard airbox, which tyga reccommends Fr.112/Rr.115 jets for. From what I can tell RB Racing at Tarren Point are a pretty well respected shop. Wondering why it would have 130 main jets, could this be part of the problem?


I also noticed that the sub air cleaner from the airbox is missing, i have ordered one of these as well as a genuine air filter. I have also noticed a lack of torque in the mid range, which seems to be a common problem. This seems to be supported by the dyno graph. If the carbs need to be removed to be cleaned to remedy the missfire/stuttering issue, should I add an extra washer to each need to solve the lack of mid range.


Any ideas of other things to check would be appreciated, cheers.

Windy conditions cause the issue or is it a headwind that requires more throttle that causes the stutter? 108 main jets are std nc35, 130 would appear to be very large although it would only affect 3/4 to full throttle. The nc35 has a reputation for a flat spot around 6000 rpm that is reduced by raising the needles slightly.

Windy conditions cause the issue or is it a headwind that requires more throttle that causes the stutter? 108 main jets are std nc35, 130 would appear to be very large although it would only affect 3/4 to full throttle. The nc35 has a reputation for a flat spot around 6000 rpm that is reduced by raising the needles slightly.

Yes, the issue is caused via windy conditions, or speed above 90km/hr.

Windy conditions is a bit vague can you be more specific. All speeds above 90 or does it improve at some higher speed. Engine revs out cleanly to more than 10,000 rpm in all gears?

All speeds above 90 or so, gets worse with speed. At lower speeds say 90-110km/hr, it will rev cleanly to around 9000 rpm. Higher speeds it just becomes constant. Regardless of what gear.

In neutral does the engine rev cleanly to 12,000 rpm.

Yes, will rev cleanly in neutral all the way to redline. Will also rev cleanly to redline in first and second gear. Only once it gets over a certain speed, or at a slower speed with a higher velocity headwind will it stutter.

And this all started when?

After not starting the bike for about 6 weeks, flooded one cylinder, fouled the plugs. Was fine for a week or so after new plugs, then the issue developed.