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Discussion Starter #1
Just making sure i understand this correctly... when adjusting the the float fuel level in the float bowl. I use the rubber tube and make sure the fuel comes out:

"To a level, 7.5-8.5mm below the line on the fuel bowl cover."

http://650ccnd.com/floatbowl.htm

Im following this, but want to make sure i understand it correctly. Currently they are lining up with the line, or higher, which explains the major rich issue i have. So i will be adjusting to fix that.

Has anyone discovered which direction to bend the tang to get the fuel level lower in the float bowl? Everything i have read says either or... just trying to make sure i dont have to spend a weekend installing/uninstalling.

Is there also a different way to measure from the gasket area? I noticed that many Mikuni carbs can be adjusted with no gas in the bowl while carbs are out the bike, and using a caliper to measure and set the float height correctly. I can not find these procedures for the BDS28, the 32/34 yes, but not the 28.
 

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Old post indeed... what I ended up doing was just adjusting the floats similar to how you would a harley carb. With the new carb kit you just bend the tang a hair until the float itself is level with the carb body. What I would do is tilt the carb so that the float falls into the carb... look at it from the side and then make the float parallel to the carb body, where the gasket sits. You dont want a ton of pressure on the needle, but you want it seated.

Hope that is somewhat clear... make sure you sync your carbs afterwards of course.
 

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If the fuel level is too high then you bend the tab towards the fuel valve. I don't bother with static measurements of the float height when the carb is upside down or other such methods... I measure 'dynamically' by removing the bowl retaining screws, hold the bowl to the carb which is at it's 'working' position, allow fuel to flow into the bowl until the valve closes, allow the bowl to drop and see how high the fuel level is in the bowl and adjust the float accordingly.
 

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Found this dry bowl procedure:

Preliminary Float Height Setting (Benchtop or dry Method)

I used the same procedure ("Harley way") to adjust floats on my wife's old 650 and it worked ok (it says Preliminary though so fine tuning may still be required). You will need to sync the carbs and I'd suggest to pull and check spark plugs after few hundred miles.
 

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Found this dry bowl procedure:

Preliminary Float Height Setting (Benchtop or dry Method)

I used the same procedure ("Harley way") to adjust floats on my wife's old 650 and it worked ok (it says Preliminary though so fine tuning may still be required). You will need to sync the carbs and I'd suggest to pull and check spark plugs after few hundred miles.
Hello there, I have a 2000 VSTAR 650 Classic and I see that you said you used this procedure on the 'old 650'. Someone messed with the float tang and it is not even pulling out the needle. I need to set an initial float height before I put it back on the bike and then the shop manual instructions to tweak it. Was the instructions accurate at the mm you used to initially set the float height on the bench? Can I ask what year 650 the bike is?
 

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Hello there, I have a 2000 VSTAR 650 Classic and I see that you said you used this procedure on the 'old 650'. Someone messed with the float tang and it is not even pulling out the needle. I need to set an initial float height before I put it back on the bike and then the shop manual instructions to tweak it. Was the instructions accurate at the mm you used to initially set the float height on the bench? Can I ask what year 650 the bike is?
Hi, yes I used that procedure to adjust the floats since I didn't have a gauge, but unfortunately I don't remember if numbers in the instructions worked or not. I believe they worked since it's the same carb.

The 650 we had was 2004. I suggest to try the average number (6.2 + 8.2) / 2 = 7.2 and see how bike runs. You could also probably make that gauge to set the floats yourself since it's just a U-shape clear tube (need to find a correct diameter and material to make sure it is gasoline-resistant). Float bowl has a mark where the fuel level should be when the float height is correct.

After you done with your carbs I suggest to pull the spark plugs as they are good indicators of AFR. And of course carbs need to be synced or they will never work right.

Hope this helps, good luck!
 

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Hi, yes I used that procedure to adjust the floats since I didn't have a gauge, but unfortunately I don't remember if numbers in the instructions worked or not. I believe they worked since it's the same carb.

The 650 we had was 2004. I suggest to try the average number (6.2 + 8.2) / 2 = 7.2 and see how bike runs. You could also probably make that gauge to set the floats yourself since it's just a U-shape clear tube (need to find a correct diameter and material to make sure it is gasoline-resistant). Float bowl has a mark where the fuel level should be when the float height is correct.

After you done with your carbs I suggest to pull the spark plugs as they are good indicators of AFR. And of course carbs need to be synced or they will never work right.

Hope this helps, good luck!
Thanks for the response. I was surprised you responded, because the post was almost 3 years ago. I have the fuel tube to do the shop manual test. I just need a place to start on the bench. Thanks for the suggestion about the spark plugs and syncing the carbs. I need to get this thing fired up and I'm so excited. Thank you again, i'll post an update when i succeed. 7.2mm will be the lucky number. Thanks again.
 

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Thanks for the response. I was surprised you responded, because the post was almost 3 years ago. I have the fuel tube to do the shop manual test. I just need a place to start on the bench. Thanks for the suggestion about the spark plugs and syncing the carbs. I need to get this thing fired up and I'm so excited. Thank you again, i'll post an update when i succeed. 7.2mm will be the lucky number. Thanks again.
Hope it helps and bike fires right up. I still wonder around this forum even though we no longer own any Yamaha bikes, it's all about people here.

Sent from my SAMSUNG-SM-G925A using Tapatalk
 

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That's cool of you to still contribute to the forum. The information you hold is exactly what I needed and I can't find anywhere else. I'm a new rider and can't wait to get this thing fired up.
 

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That's cool of you to still contribute to the forum. The information you hold is exactly what I needed and I can't find anywhere else. I'm a new rider and can't wait to get this thing fired up.
You will find help here I promise, there is a lot of knowledgeable riders on the forum, stick around and we all get your bike running. I suggest you to get in touch with KCW since he owns 650 and knows that bike very well. Remember, if it was designed and built by humans it can be fixed by humans lol

Again, best of luck and do not hesitate to ask for help!
 
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