TOPIC:

Nessism wrote: There should be a float height measurement somewhere. I know Suzuki, which uses VM carbs on most of their early GS family bikes, has the height listed in the service manual. Tweaking the floats to register the correct height will make the trial and error process of fine tuning the fuel level easier.

With the carbs upside down, if the weight of the float cause the spring loaded tip of the float needle to compress you should consider changing the needles. They will still work but the fuel level will be higher and less reliable than if the spring tips are stronger.

The measurement for the floats is helpful in getting started for sure, the clear tube is the fine tuning. Usually I find 3 of the 4 are close to spot on, but there's always the one that has it's own thing going. On a single carb float height is less critical, within a range, but on 4 carbs you need them the same to ensure the same mixture going to the carbs. The clear tube is the only way to do that, given that the floats might not all weigh or float exactly the same and there could be variances in the float needles etc.

Always start with the float body measurement, to get you in the ball park so the bike will run...enabling the ability to do the clear tube test"
Where do all you people, that claim to only us the clear tube test, set the float initially????
In all my years of experience, I have never found a large variation, using either/both methods..... The important part is that they are all the same. as close as humanly possible

ezrider714 wrote: Always start with the float body measurement, to get you in the ball park so the bike will run...enabling the ability to do the clear tube test"
Where do all you people, that claim to only us the clear tube test, set the float initially????
In all my years of experience, I have never found a large variation, using either/both methods..... The important part is that they are all the same. as close as humanly possible

One helpful factor is that even though a lot of carbs are "crudded up" and neglected because the bike has sat for years. the float heights are often as set at the factory so regularly you get pretty lucky and they are pretty close unless you are really unfortunate and someone really incompetent has been working on the carbs. Most of the carb "bodgers" don't mess with the floats, they are usually to busy rounding of screw heads and cross threading things.

If possible I'll check the float heights with the clear plastic tube before taking them off the bike, or before dismantling them, that way you know if adjustments are needed and which way to bend which float tab, if at all. As often many have not been molested, this avoids doing a dry setting and then perhaps adjusting them back to where they already were when you get to the clear tube stage.

And why would you need the bike to run before you do the clear tube test ????