Raptor Forum banner
1 - 14 of 14 Posts

·
Registered
Joined
·
266 Posts
Discussion Starter · #1 ·
Ok guys I have a problem that’s driving me nuts. I completely cleaned and rebuilt the carbs. To rebuild the carbs I used the Shindy rebuilt kit it comes with all new parts including needles and valve seat. But now when I go to adjust and get the fuel level just right the left carb keeps changing the fuel keeps climbing. I set the float to where its about right but it keeps changing on me. So thinking I got maybe a bad O ring on the valve seat I went to the auto part store and found one that works. So I put the new ring in and still the fuel level keeps jumping up. I cant get a stable fuel level. So guys what else can I check for that would let more fuel into the carbs?
 

·
Master of the Electron
Joined
·
15,680 Posts
check alignment of the float needle in the seat - if the tank on float is bent wrong, it can shift the needle sideways, preventing full shutoff.

Edit: Should read "tang" not "tank"
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #3 ·
check alignment of the float needle in the seat - if the tank on float is bent wrong, it can shift the needle sideways, preventing full shutoff.
Will do thanks.
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #4 ·
I checked the needle and it looks like its moving just fine with the tang. Now what are some steps you can take to check then needle itself? How do you know if you have a bad needle? What to look for on a needle to figure out if you have a bad one?
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #6 ·
Bump
 

·
Master of the Electron
Joined
·
15,680 Posts
put a piece of clear vinyl tube on the bottom drain, open the drain screw and raise the end of the tubing above the gas tank... if the float valve closes, the level of fuel in the tube will stop at the level in the bowls. If the valve is stuck open, or the valve, seat or o-ring is leaking, the level in the tube will eventually reach the level in the tank.
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #8 · (Edited)
put a piece of clear vinyl tube on the bottom drain, open the drain screw and raise the end of the tubing above the gas tank... if the float valve closes, the level of fuel in the tube will stop at the level in the bowls. If the valve is stuck open, or the valve, seat or o-ring is leaking, the level in the tube will eventually reach the level in the tank.
Yup that's what I bin doing. I use a clear peace tube to measure the fuel level. The way I know the fuel level changes on me, is when it seams that I get the right fuel level I just simply lower the hose below the carbs and fuel will try to run out the tube so I lift it pass the gas tank and the fuel level will then drop back down. So I go to check it and it has changed on me. I repeat lower the hose and then lift it over the gas tank and set the hose against the carbs and it will continue to raise every time I do it. The needle and seat are brand new I did replace the o ring with a brand new one just in case. But no go can't figure it out.
 

·
Master of the Electron
Joined
·
15,680 Posts
IT will raise when you do that... when moving, you're using the inertia of the fuel in the tube as a pump with the float valve as the pump's check valve.

Don't move it, just put the hose above the carb level and leave it alone... this will show you the current float level when it stops rising. If it DOESN'T stop rising (when left alone, unmoved), however, you do have a problem.
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #10 · (Edited)
IT will raise when you do that... when moving, you're using the inertia of the fuel in the tube as a pump with the float valve as the pump's check valve.

Don't move it, just put the hose above the carb level and leave it alone... this will show you the current float level when it stops rising. If it DOESN'T stop rising (when left alone, unmoved), however, you do have a problem.
I understand what you are saying. But why then when I do the same to the right carb the fuel level will want to run out of the hose when I lower the hose down below the carbs? But when I raise it over the gas tank the fuel will drop back down and when I set it against the carbs the fuel will be where I originally had set it with no change. When I do same to the left carb and go to lower the hose and set it against the carbs the fuel level will be different too what I had set it originally and if I keep lowering the hose and lifting it back up the fuel will always rise a little more every time I do it.
 

·
Master of the Electron
Joined
·
15,680 Posts
The right one is not acting as I would exepct. perhaps its drain screw is not open?
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #12 · (Edited)
The right one is not acting as I would exepct. perhaps its drain screw is not open?
You know what i am wrong its backwards. Post #8 and #10 have been edited. SORRY
 

·
Registered
Joined
·
266 Posts
Discussion Starter · #13 ·
Bump
 

·
Master of the Electron
Joined
·
15,680 Posts
I understand what you are saying. But why then when I do the same to the right carb the fuel level will want to run out of the hose when I lower the hose down below the carbs? But when I raise it over the gas tank the fuel will drop back down and when I set it against the carbs the fuel will be where I originally had set it with no change. When I do same to the left carb and go to lower the hose and set it against the carbs the fuel level will be different too what I had set it originally and if I keep lowering the hose and lifting it back up the fuel will always rise a little more every time I do it.
Okay, THIS one I CAN explain, but it's pure conjecture.

The right carb float valve has more friction and takes longer to close than the left. The left, when you raise the tube up and down, opens and closes with the inertia of the fluid fluctuations in the bowl, and acts something like a pump - raising the fluid level. THe right, being slower due to the excess friction, doesn't follow the tube motion and therefore, doesn't pump more fuel into the system.

Again, pure conjecture. Now it's time to see how the bike runs, and stop worrying about some small, most likely not significant phenomenon that has little to do with normal operation of the float valves. I suspect you won't see any issues related to this small difference between the carbs, and under normal operation, there is no tube containing fuel outside the float bowl.
 
1 - 14 of 14 Posts
Top