Crypton MotoMetor carb balancer, model B91

[daverclasper]

Hi. I have always used a piece of tube and my ears for this, though getting deafer nowadays.

 So I bought the above, used item at a cheap price. No instructions were supplied and I can't find any info.

Its an alloy bodied one with a transparent plastic/glass? metering tube coming out of the side, in which a free sliding metal thing inside the tube moves up and down according to the amount of air drawn into the carb throat.

It looks straight forward to use, though there is a half spherical ball in the throat of the thing (facing the carb) with a gap all around of maybe 4mm that presumably allows the air into the carb and into a smallish hole/passageway to the metering tube. This gap size appears to able to be adjusted?.

Anyone here used this tool?. I would send a photo, though have never managed to do it it with my Android phone?

Thanks, Dave 

Edited August 19 by daverclasper

[Peter Truman]

Think its the same as mine brought it in the UK pre 74, you can adjust the float arm over 90 degrees to get it vertical, then the float position can be regulated in the tube by rotating the center domed dish (with the spring attached) with the little pimples on it to open or close the air passage thro the center throat so you can get the float position where you want it BUT keep that adjustment when using on the second carb so your comparing apples!

I found these instructions years later on the web

Hope this helps

[Pete Lewis]

yes very simple and reliable unit  , just turn the centre to create enough vacuum to float the ball in the tube

this was all coverd on the spanish members post  

i have made a relief in the rubber pad so it cant block any of the front face ports of the carb air cleaner face .

dont forget the old trick with a marked drinking straw down the dashpot to compare piston running heights  

Pete

[Peter Truman]

1 hour ago, Pete Lewis said:

yes very simple and reliable unit  , just turn the centre to create enough vacuum to float the ball in the tube

this was all coverd on the spanish members post  

i have made a relief in the rubber pad so it cant block any of the front face ports of the carb air cleaner face .

dont forget the old trick with a marked drinking straw down the dashpot to compare piston running heights  

Pete

Ref old trick around 64 when I had a Sprite I brought a carb tuning kit of two thin rods of steel with like paper clips bent on the ends which went down the SU dash pots and you put the two ends of the rods to each other then increased the revs and checked how they rose together to balance the carbs. A bit of a faff!

[daverclasper]

Thanks guys, very useful stuff.

Pete? Would you be able to provide a photo of the relief you did to to sponge bit please?. I remember your tool on Twiddle Day, though can't remember the modification

Thanks 

[Pete Lewis]

dave its just remove a bit of the face foam gasket if it tends to cover the vent holes , 

its nothing special , just  a light attack with a stanley blade 

if you have a vent and you cover it it will upset the running 

will try a picture if it starts to  Rain  Ha !

Pete