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Measuring the float height

Posted: Sun Jul 31, 2016 7:16 pm
by Kmamac
Hi, I have replaced the needle valve (and washer) that feeds the float chamber with fuel. Having read the posts here it's obvious the height is critical. However, what exactly is one measuring up to for this height? The plastic float is all angles and curves around 42mm dimension. Pictures on line seem to show a different shape float. In frustration I tweaked it to be about where the old valve and washer was, making the assumption it ran ok before. Could some one kindly point me to a diagram or explanation as to what edge, surface etc I'm supposed to be measuring to.
I thought the dellorto s were a bit of a pain with float height but this is seems to be at a whole new level of frustration.
Many thanks in advance
Keith mm

Re: Measuring the float height

Posted: Sun Jul 31, 2016 7:40 pm
by Thebenelliman
I found this on a previous post on here I hope it helps?
...and the inevitable follow up question, when you are measuring the 42mm from the surface of the gasket to the bottom of the float when it is just touching the needle where exactly on the float do you measure as it varies depending on the position
It's the middle of the float!

Re: Measuring the float height

Posted: Sun Jul 31, 2016 8:36 pm
by Mc tool
Usually what you do is to hold the carb top upside down ( so the float tang is resting against the needle ) and measure from the gasket surface ( no gasket ) to the highest part of the float.

Re: Measuring the float height

Posted: Mon Aug 01, 2016 8:37 am
by Derek
Hopefully this will make it clear -

Image

Re: Measuring the float height

Posted: Wed Aug 03, 2016 9:58 pm
by Kmamac
Thanks for that Derek. If you look at the two photos you can see my dilemma. The first one is as I discovered it. It looks miles out and with the angle of the float it's not actually easy to say exactly what the float height is.
The second one is after I have given the float tab an almighty bend down. This gets the top of the float nearer to horizontal and closer to 42mm. If the second photo is more like how it should be I am curious how the thing ever ran before. Ok I know I need the gasket on there as well (struggled to hold it flat as well as rule to get photos).
Am I on the right path with this now?
Best regards
Keith mm

Re: Measuring the float height

Posted: Wed Aug 03, 2016 10:34 pm
by higgy
generally when the float is level with the top you are close

Re: Measuring the float height

Posted: Thu Aug 04, 2016 8:39 am
by Kmamac
Thanks Higgy that is what I need to hear. It makes more sense now. I have no idea how it ran before but if I have had to change the float height so much I suspect there may be other issues in the setup. I'm sure I will find your other carb posts most useful in the coming weeks.
Best regards
Keith mm