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Discussion Starter · #1 ·
sorry for the newbie question , but just got it and need to order a service manual this week . some keihin's do some don't on other brands . from looking at these they don't , but like i said just got it and was wondering .

thanx
 

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Discussion Starter · #3 ·
actually keihen cv's on sportsters have pumps
 

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CV carbs are great for drivability throughout the year, essentially once set they are best left alone. Accelerator pumps as found on Keihin FCR type carbs, where the throttle cable actually moves the slide, they are needed to compensate for the lean moment that occurs when you open the throttle - by shooting a thin squirt of fuel directly down the inlet - poor man's fuel injection! getting the timing for that 'squirt' is what gives fcr's a bad name, as most tuners are unfamiliar with how to alter that timing - hence there bad rep. These carbs will give you better performance than a CV type carb but at the expense of frequent jetting to maintain optimum performance, they are temp/altitude sensitive . However they do just fine once set up for the environs one rides but as the letters suggest FCR = flatslide carburator racing - not a carb for touring. :razz:
 

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These carbs will give you better performance than a CV type carb but at the expense of frequent jetting to maintain optimum performance, they are temp/altitude sensitive .
I think either carb will give you the same performance when properly set up, since 'set up' means providing the correct air:fuel mixture to the engine.

The problem is that the CV carbs (as installed by Triumph) were simply not designed with adjustabilty as a priority so they're quite difficult to get working properly.

Jim
 

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Discussion Starter · #7 ·
thanx guys appreciate your input but when i said newbie , i meant newbie to owning a triumph triple .

my buell has a cv w/o an accel pump , my friends sportster has the exact same carbs on his sportster (yes theyre the orig stock carbs) and his cv's DO have pumps ! i've had both sets apart to rejet , an absolute must when you go freeflow on exaust and intake .

the reason i was asking was when i got my bike home it'd just drove 2 hrs in sub freezing weather in the back of my pickup and first try at starting her i fouled the plugs . it wouldn't start by just fully engageing the choke and hitting the switch . fresh plugs and a warm garage and all was good to go .

the other reason i was asking was when my wife got home as was checking out my new steed she sat on it and twisted the throttle a few times . no pump no big deal , with pump a no-no .
here's an article on rejetting cv's and it doesn't get into the pumps except half way down the page

Replace the float bowl, carefully placing the accelerator pump rod into its rubber boot.
CV Mods

now if this white stuff would melt , i'd actually be able to ride her :(
 
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