9 replies to this topic

[mh1848]

well after adjusting shims going to set fuel levels in carbs - now i have the calibrated hose - but i just cannot get it to read properly - only just moving above level line on float bowls -

 

is there a knack to this? or might it be that my fuel levels are that low that it is only just climbing above the mark on teh float bowls?

 

suggestions welcome

 

[Studley Ramrod]

A couple o suggestions   Make sure the float bowl screws are opened a good 2-3 turns and make sure the fuel supply to carbs has a good head height.

[Bjørge]

I have a problem seeing how one can read these levels so accurately - easily miss a mm or two on readings ?

[Studley Ramrod]

I marked the Float bowls using some tape.

 

[Bjørge]

Yeah, but +-0.5mm !!! - do you measure at the bottom of the gasoline "column" or the average ? 

I really have a problem believing that these measurements are reliable within 1mm. 

 

BTW, how did you (if the picture is taken by you) manage to do this setup with carbs out of the bike ?

[Studley Ramrod]

I just get the measurement as close as possible.  As you say, 1mm is not a lot to play with.

 

I set the carbs up on my wooden stepladders so that they're at the same angle as they would be when fitted to the bike and use a remote fuel supply to feed the carbs.

[mh1848]

I set the carbs up on my wooden stepladders so that they're at the same angle as they would be when fitted to the bike and use a remote fuel supply to feed the carbs.

 that is the approach i am going to adopt  - measured roughly angle they sit at and will reproduce that on bench and make sure temporary fuel supply is high enough

[overthrottle]

I found that if I removed the battery box (very simple to do, just two easy to access bolts) I had a lot more room to do this on the bike. That way I was able to make sure the carb angle was correct, and I also was able to use the fuel pump on the bike (I installed an electric fuel pump at the same time to eliminate the plague of vacuum pump problems potentially stranding me).  It's important that the fuel line pressure be the same as what the bike will see, because that can also influence the carb fuel level (the fuel pressure will push on the float needle, resisting the carb float from closing fully).

 

I just used a spare length of clear fuel line, and I made a line with a permanent marker, and then two more dots for the proper distance from the line.  As long as I hold the fuel hose line next to the line on the carb, the dots will indicate the correct height (min and max).

 

Worked pretty well for me. I had a couple issues in the beginning getting air bubbles out of the fuel hose, but once I had them burped out, it worked really well.

 

 

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Edited by overthrottle, 01 October 2014 - 02:46 am.

[g650xtdm]

I basically did the same method Overthrottle used.  I drew a line and lined it up on the carb and then marked where the fuel level was.  I could then pull the fuel line back to easily measure the distance.  Of course, the lines I drew were probably .5mm thick each, so who knows if I was actually in the correct range.  But I figure it gets it as close as is reasonable possible. 

[mh1848]

well with a bit of perseverance and the pictures above, plus some springs fitted over the tube to stop it kinking, i managed to measure the fuel height. Bad news is they are low - 4mm left, and 5mm right carb - so some fiddly tinkering to adjust

 

thanks to all that responded