choke question

[SkyfangR]

i want to re-jet my bike, because i prefer a slightly rich mix over the lean mix that my bike has.
can i used the choke at say, 1/4 on to achieve the same result (enriching the mix) until i can do the job properly?

[tom203]

No.....you’ll mess up how the vacuum diaphragms react as you increase load.
does PA require a bike emission test?
If your carbs are properly cleaned, bike will run correctly with original air box/filter setup

[Rich82GS750TZ]

PA does not require emissions testing at annual inspection for motorcycles. Other vehicles may require emissions depending on the county in which they are registered.

https://www.emissions.org/loc/pennsylvania-emissions-testing/

[Burque73]

Maybe get some tiny washers and shim the needles to richen it up a bit.

[Who Dat?]

The only time the "choke" richens the mixture is when the throttle is completely CLOSED. If that's the way you ride, it will work, but most of us enjoy opening the throttle a bit more than that.

Depending on what modifications you have done to your bike, you can probably get away with simply turning the pilot screws out a bit. In their stock setting, they were very lean, to meet EPA regulations that were being imposed at the time. Turning the screws out 1/4 to 1/2 turn will do wonders for the way it runs.

Now, if you have removed the stock airbox and/or installed "free-flowing" exhaust, you will need to re-jet eventually. Keep in mind that most of the need to re-jet is because you have removed the restriction of the stock airbox. That restriction is mainly at higher engine speeds and full throttle. Keep the revs down and keep the throttle at more-modest settings, you will be OK.

[SkyfangR]

thanks for the info. ill try fiddling with the pilot screws a bit

[gs11ezrydr]

The only time the "choke" richens the mixture is when the throttle is completely CLOSED. If that's the way you ride, it will work, but most of us enjoy opening the throttle a bit more than that.

Depending on what modifications you have done to your bike, you can probably get away with simply turning the pilot screws out a bit. In their stock setting, they were very lean, to meet EPA regulations that were being imposed at the time. Turning the screws out 1/4 to 1/2 turn will do wonders for the way it runs.

Now, if you have removed the stock airbox and/or installed "free-flowing" exhaust, you will need to re-jet eventually. Keep in mind that most of the need to re-jet is because you have removed the restriction of the stock airbox. That restriction is mainly at higher engine speeds and full throttle. Keep the revs down and keep the throttle at more-modest settings, you will be OK.

Totally agree...Except the choke will effect the whole fuel range...The choke will foul plugs,dilute the oil,turn your pipes blue (if chrome) and smog up everything..Tune it...That's all.

[zed1015]

The only time the "choke" richens the mixture is when the throttle is completely CLOSED.

Sorry! but that is incorrect.
On VM, BS and most (but not all) modern motorcycle carbs the "choke" ( Which is in fact usually an enrichening device and not an air restrictor ) supplies fuel direct from the float bowl via it's own independent circuit.
Once opened it will supply additional fuel drawn by the lower atmospheric pressure in the venturi ahead of the slide and increase the fuel to air ratio of the mixture delivered to the combustion chamber no matter what throttle position .
Because of this it can be used to help diagnose fuelling faults and determine over lean or rich mixtures by feathering the choke at the throttle opening where the issue occurs.
Riding with the choke on or with a faulty plunger seal will cause rich running, power loss, lowered mpg and over a period of time accelerated bore and ring wear.