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purchased a 2007 Yamaha v star 1100 off a friend, motorcycle barely idled and had been sitting for a while when i first got it so i replaced the
2.fuel pump
3. drained and cleaned the fuel tank completely and refilled with fresh gas
4. NGK spark plugs BPR7ES gapped between .28-.31 in
5. new K&N air filter and oil filter
6. oil changed with mobil 1 20w-50
Then i rebuild the carburetor making sure to clean every single diaphragm, bowl and all orifices. i replaced the needles,jets, or verified good clean passage through the main jets. the carb is in good shape.

Today i tried to make sure the carb sync was good and when i hooked up my gauges the would rapidly change from almost 20 in HG to +5 psi of air. very very rapidly. not sure if the rpm is set right either. i have a inductive tachometer coming in a couple of days to set proper rpm between 950-1100. when i went to sync the carb the bike was fully warmed up and the choke was off.

one thing i have noticed is that if i try to choke the bike out at all when i first go to start it, it will not start. but i let the fuel pump, pump a few times then fire it up it will mostly run then die and then run until it warms. it runs good enough to start and drive but the choke will kill the bike.

my question are
1. are the needles suppose to rapidy change when idling
2. why does the choke prevent the bike from starting even when cold.

also there are some hairline fractures on the small rubber intake hoses attached to the cylinder head where the carb goes into and one of the intake boots is a bit folded over. just things i have noticed. i am new to working on bikes but have been a car mechanic for 5 years. thank you and i will answer any extra questions for bike info
 

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purchased a 2007 Yamaha v star 1100 off a friend, motorcycle barely idled and had been sitting for a while when i first got it so i replaced the
2.fuel pump
3. drained and cleaned the fuel tank completely and refilled with fresh gas
4. NGK spark plugs BPR7ES gapped between .28-.31 in
5. new K&N air filter and oil filter
6. oil changed with mobil 1 20w-50
Then i rebuild the carburetor making sure to clean every single diaphragm, bowl and all orifices. i replaced the needles,jets, or verified good clean passage through the main jets. the carb is in good shape.

Today i tried to make sure the carb sync was good and when i hooked up my gauges the would rapidly change from almost 20 in HG to +5 psi of air. very very rapidly. not sure if the rpm is set right either. i have a inductive tachometer coming in a couple of days to set proper rpm between 950-1100. when i went to sync the carb the bike was fully warmed up and the choke was off.

one thing i have noticed is that if i try to choke the bike out at all when i first go to start it, it will not start. but i let the fuel pump, pump a few times then fire it up it will mostly run then die and then run until it warms. it runs good enough to start and drive but the choke will kill the bike.

my question are
1. are the needles suppose to rapidy change when idling
2. why does the choke prevent the bike from starting even when cold.

also there are some hairline fractures on the small rubber intake hoses attached to the cylinder head where the carb goes into and one of the intake boots is a bit folded over. just things i have noticed. i am new to working on bikes but have been a car mechanic for 5 years. thank you and i will answer any extra questions for bike info
Yes, replaced that spider web cracked intake. Also, I noticed you said you “cleaned” the carb as said you rebuilt it, but I didn’t see where you replaced the diaphragms. There may be leaks there since “spider webbing” is a sign of deterioration. Possible leaks though you can’t see them.
I’d start there.

FYI, I used to own a 91 Venture Royale and did my own work on it.
 

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The jumping of vacuum gauge is normal on Vtwins. Easiest way is to put an old jet in the vacuum line to dampen the bounce, they actually sell line restriction device but do the same thing as a jet. The intake boots have a metal sleeve in them and very seldom actually leak. You can test the intake boots by spraying some starter fluid on them with bike running. If RPM raises, replace them.
 

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The jumping of vacuum gauge is normal on Vtwins. Easiest way is to put an old jet in the vacuum line to dampen the bounce, they actually sell line restriction device but do the same thing as a jet. The intake boots have a metal sleeve in them and very seldom actually leak. You can test the intake boots by spraying some starter fluid on them with bike running. If RPM raises, replace them.
Exactly! I forgot about the starter fluid trick.
Good take @lesblank !
 

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HOw are you choking the bike?

first off you need to let the fuel pump run when you turn the key on until it stops running BRBRBRBbrbrbrrrrr..... Its should stop in 3 to 5 seconds when the bike has sat a long time

when you can hear it, its filling the float bowls

normally you pull the choke out all the way to start it and dont give it ANY throttle,

the choke flow is designed for a closed throttle plate

when it fires push it in half way for a few minutes, then push it in all the way.

If the bike wont start with the choke out when its overnight cold, PMscrews are too rich.

How did you set the PMscrews when you had them out and cleaned them?

Its also possible you have the float position adjusted too high, and the float bowls are over filling or over flowing.

If the fuel pump runs continuously when you turn the key on, the floats are not closing - probably spewing out the overflow tube on the top right side of the engine case.
 
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