Carb jetting
- Thread starter clinton
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concours
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Your problem is obvious.
Revving to 45000rpm is asking too much. Upshifting at 43000 is a better way to use the available tork.
marshg246
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What jet are you talking about - there is no 22. If you mean 220, then that is correct or 230 is listed some places. If you mean 4500 RPM, that has nothing to do with the main jet. How many RPMS at 1/2 throttle in 3rd gear?
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Does it still have the balance pipe exhaust as I've heard black caps need it to work properly although I'm not sure how accurate that is, that's if the black caps aren't breaking up internally. Probably better to fit a pair of peashooters and likely 260 main jets.
Those foam black airbox filters break up so is it reasonably new or still in good condition?
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If you have filled the oil tank to the top mark on the dipstick then excess oil will be breathed into the air filter and block the foam filter. Only ever fill to 1/2 way between the two marks on the dipstick. The foam filter breaks up over time and best to fit a new one.
Has balance tube on exhaust , everything is in good condition and it ran well with peashooters.i have just fitted black caps oem in good nick
Fast Eddie
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What number slides do you use ?
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The ones in there, which have not seen the light of day for many years. If wrong that only affects the transition from pilot circuit to main circuit ie bottom 1/4 throttle opening.
ashman
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Seems like no maintenance has been done to your carbs, changing mufflers the carbs need to be tuned part of tuning is jets, needle positions, a good clean out as well, depends on the mileage jets do wear out from vibrations.
Open pipes bigger jets, restricted pipes smaller jets, but each bike is different, just got to tune till you find the sweet spot for your riding style.
Open pipes bigger jets, restricted pipes smaller jets, but each bike is different, just got to tune till you find the sweet spot for your riding style.
220
acotrel
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If main jets are too rich, it does not usually stop the motor from revving out. The exhaust system is a more likely cause - if it is restrictive, it can cut the top off the power band. When you jet the carbs , needles and needle jets are critical. They need to be as lean as possible without causing damage, If the mid-throttle jetting is nice and lean, the motor will usually rev-out really well and when you begin to use the main jets, their oversize becomes less relevant. If the bike is under-geared, it can rev without pulling. The Commando engine is deceptive, it is faster when it is forced to pull. It always seems to spin-up at the same rate whether the gearing is high or low.
acotrel
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I think some guys must ride by whacking the throttle open. If the midrange jetting is right, the bike will usually be much faster when the throttle is fed-on in a controlled fashion. If you get onto the main jets too quickly, the acceleration rate can be slower. People who are not accustomed to road racing are often slow around corners the grab a handful of throttle when the bike is upright and pointed in the right direction. It is always faster to accelerate through corners from the point where braking into them stops.
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