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Discussion Starter #1
Maybe someone can chime in and explain what happened better than I can, but here's a solution to what's been called, on the internet, a common problem with the V-Star 650. This is also a problem that doesn't seem to ever get a straight answer given as to how to fix it, hence why I wanted to post here.

Background: I bought a 2001 V-Star 650 with 7400 miles on it for $420. The guy said he hadn't rode it in about 3 years, the plates expired 5 years ago.

I bought the bike, and got my brother to rebuild the carbs. It started on full choke, but died on closed choke. I recleaned the carbs a couple more times, and it started idling well with the choke closed.

When I twisted the throttle, the bike would rev up until about 1/2 throttle, and then start to die while in neutral. When in gear, it gave no indication of having any power. (This is the problem I've seen described elsewhere, but with no answer ever given.)

My brother suggested that the carbs were sucking in too much air, from a possible leak somewhere. I checked all of the vacuum tubes, the intakes, etc, with no luck. Nothing I did would get the carbs to stop sucking in too much air.

Finally, I stumbled across the solution. During all of this testing, I had the air filter assembly off of the bike. Apparently, the air filter housing and assembly restrict a lot of air from the carburetors.

Reinstalling the assembly in full caused my bike to run perfectly.

I don't know if this will work in all cases, and I may be wrong about this being the same problem as some of the others I've read about on line, but thought I'd let others know what worked for me.

If anyone else can explain why it works, or correct me if I'm wrong about what fixed my bike, please chime in. I'd love to understand more about how this bike works.
 

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not really a solution, its common knowledge that most bikes run WAY lean with the air filter assembly off. Which is why when we install PODS on out 1100's and INCREASE air flow, we also have to INCREASE fuel flow to match. Glad you got your bike running well, and are familiar with the carbs! Sounds like you got a great deal!
 

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It's common for 650 riders to take off their air filter assembly and then wonder why their bike isn't running too good?

Man, what a wacky bunch! :p

Most carbs are setup for use with an air filter and to apply a certain amount if gas to that amount of air coming through said filter.

By taking off the filter, you're introducing a lot more air but not changing the fuel ratio.
 

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Discussion Starter #6
Never run without an airfilter. That's just asking for issues.


Sent from Motorcycle.com Free App

I wasn't trying to necessarily run it w/o an air filter. I was trying to test it after rebuilding the carbs...lol. You can actually do things like that with a car engine, which I have a lot more experience with. I would never try to actually run any vehicle for long w/o an air filter.

Unfortunately, as obvious as this may seem to people with more experience than some of us, those with less experience seem to have problems with it. I've seen multiple posts of people with the exact same symptoms on their bikes around the internet, but no one thinks to mention the possibility of the air box. Just thought I'd attempt to put the information out there to possibly help someone else.
 

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RemQl, car's get leaned out, too, but have much larger intake runners to help develop vacuum making the problem less pronounced. Also, look at a car's choke. Notice it's an actual choke? That choke is developing vacuum to decrease the air/fuel ratio. I believe your motorcycle has an enriching circuit instead, which does nothing to increase vacuum, but needs vacuum just like the rest of the fuel circuits. Vacuum is the energy required to operate a carb. Without it fuel cannot flow (gravity's effect stops at the fuel bowl). Because of these things a motorcycle intake system is more sensitive to changes in any part of the intake system than a car by comparison.

Someone more eloquent can probably explain it better.
 
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