How to measure float height.

[Brian Cairns]

Hi
I'm new to MZ's and am asking for a bit of advice .

I have a 1977 MZ 150 TS, it uses the BVF 24N-1 carb.
I had to buy new floats but how do you measure float height?

Measurements in manual state 27mm +1 and 34mm + 1. Does this then mean you adjust height of float to 28mm ( for closed position) and 35mm ( for open position)? Does the + 1mm just take into account the gasket thickness of the float bowl so therefore add it on to height adjustment ?
Also book states that you hold carb upside down to measure closed position height ( 27mm +1) however I have read elsewhere and on You tube you should hold carb at a 35 to 45 degree angle when measuring heights?

Please bear in mind I am not mechanically minded but don't mind trying out 'simple' procedures

Thanks in advance

Brian

[Puffs]

Hi Brian!

On general principle, I'd suggest you follow the book rather than youtube.

I suspect the "+1" should read "±1", so just indicate the accuracy. So, using your numbers, the closed position should be in the 26 - 28mm range, and the open one in the 33 - 35mm range.

On the closed position, it doesn't really matter if you hold it precisely upside-down, or at a slight angle, either way the float assy will rest on the valve, with that valve in the closed position.

Btw, in that closed position you can also check if that valve still seals, by blowing into the fuel supply line, using a piece of hose. Or have a look at the float needle valve seat & the float needle; on older bikes these can wear due to vibrations.

[Brian Cairns]

Hi
Thanks so much for your advice, makes it a lot clearer for me now! I will give it a try.
Brian