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float height

Posted: 26 Jun 2025 09:00
by barney 66
Morning all, can anybody tell me where the fuel level should be in the float bowl with a clear pipe connected please ?
I have made a nut for the float bowl with a connector to put a clear pipe on, with the floats set at the correct height my level at the front of the carb so it’s accounting for the forward slope is right on the float bowl joint, is this ok or to high please ?

Thanks barney

Re: float height

Posted: 26 Jun 2025 09:29
by MickeyMoto
Unless somebody has clear float bowls I am not sure how anybody would know. I take the 10mm figure and use that hoping the original engineers had worked it out.

Are you worried there is too much fuel in the float bowl? You could try 12mm and see what happens. When I got my bike it ran OK on part throttle but would not rev out. One float was way too low, cutting the fuel too early. I did not measure it, unfortunately.

Re: float height

Posted: 26 Jun 2025 10:21
by Steve Brown
MickeyMoto wrote: 26 Jun 2025 09:29 Unless somebody has clear float bowls I am not sure how anybody would know. I take the 10mm figure and use that hoping the original engineers had worked it out.

Are you worried there is too much fuel in the float bowl? You could try 12mm and see what happens. When I got my bike it ran OK on part throttle but would not rev out. One float was way too low, cutting the fuel too early. I did not measure it, unfortunately.
With the modded nut and a clear pipe you can see the real fuel level, so much more accurate than any other way. There is a drawing in one of the dellorto manuals at least, showing the level as somewhere around 5mm below the gasket face of the bowl. Adjusting the float height by the +/- 1mm makes a lot of difference in the fuel level, so getting the level at around 5mm will have you much more 'in the ball park'. Once that is set the jets seem to perform so much more as the books suggest.

Re: float height

Posted: 26 Jun 2025 11:30
by barney 66
Steve Brown wrote: 26 Jun 2025 10:21
MickeyMoto wrote: 26 Jun 2025 09:29 Unless somebody has clear float bowls I am not sure how anybody would know. I take the 10mm figure and use that hoping the original engineers had worked it out.

Are you worried there is too much fuel in the float bowl? You could try 12mm and see what happens. When I got my bike it ran OK on part throttle but would not rev out. One float was way too low, cutting the fuel too early. I did not measure it, unfortunately.
With the modded nut and a clear pipe you can see the real fuel level, so much more accurate than any other way. There is a drawing in one of the dellorto manuals at least, showing the level as somewhere around 5mm below the gasket face of the bowl. Adjusting the float height by the +/- 1mm makes a lot of difference in the fuel level, so getting the level at around 5mm will have you much more 'in the ball park'. Once that is set the jets seem to perform so much more as the books suggest.
Thanks both, I will search for the manual but looks like my level is to high,
Thanks

Re: float height

Posted: 26 Jun 2025 12:17
by Morini Jen
This is the picture in 'The Blue Book'...

Re: float height

Posted: 26 Jun 2025 13:08
by MickeyMoto
barney 66 wrote: 26 Jun 2025 11:30
Steve Brown wrote: 26 Jun 2025 10:21
MickeyMoto wrote: 26 Jun 2025 09:29 Unless somebody has clear float bowls I am not sure how anybody would know. I take the 10mm figure and use that hoping the original engineers had worked it out.

Are you worried there is too much fuel in the float bowl? You could try 12mm and see what happens. When I got my bike it ran OK on part throttle but would not rev out. One float was way too low, cutting the fuel too early. I did not measure it, unfortunately.
With the modded nut and a clear pipe you can see the real fuel level, so much more accurate than any other way. There is a drawing in one of the dellorto manuals at least, showing the level as somewhere around 5mm below the gasket face of the bowl. Adjusting the float height by the +/- 1mm makes a lot of difference in the fuel level, so getting the level at around 5mm will have you much more 'in the ball park'. Once that is set the jets seem to perform so much more as the books suggest.
Thanks both, I will search for the manual but looks like my level is to high,
Thanks
One thing to note is that the measurement is taken with the float arm 'lightly contacting the needle' as shown above.

Re: float height

Posted: 26 Jun 2025 13:28
by barney 66
All done & checked with clear tube on the side when mounted
Thanks all