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By Adrian
#67288
Since it runs fine with the cold start in the "on" position but comes to a halt as soon as you set the cold start to "off" there is obviously something causing the carb to provide far too lean a mixture.



If you have been through and cleaned out every last jet and air/fuel passage, if you have re-set the air screw and the needle correctly, fitted all the correct washers in the right place, the float height is correct and fuel is flowing freely, then there MUST be an air leak somewhere in the carb **or** elsewhere in the inlet tract to upset the fuel/air mixture ratio, if the engine will only run with the cold start enrichener on.



A.
By Himself
#67292
Ciao Simplo, I suggest you have another look at the pilot jet in the carburettor; are you certain it isn't blocked? I experienced a similar problem with my bike when the engine died immediately the choke was taken off.
By scotty
#67305
Try a can of pressure pak carby cleaner but be careful spraying passages in carby, some come back on themselfs, I got sprayed in the eyes mega painful.
Sometimes fine pilot jet holes in the side of it get blocked you can still see through main hole bit of probeing with some soft wire does the trick.best of luck.
By scotty
#67306
Try a can of pressure pak carby cleaner but be careful spraying passages in carby, some come back on themselfs, I got sprayed in the eyes mega painful.
Sometimes fine pilot jet holes in the side of it get blocked you can still see through main hole bit of probeing with some soft wire does the trick.best of luck.
By AndyMc
#67311
Big lump of Plasticene some soapy water and an air line. Cover carb and inlet with soapy water make sure inlet valve is closed and use plasticene to seal The airline in the mouth of the carb. Gently blow air in and bubbles will show if air leak is present.
User avatar
By Leon Novello
#67312
Is it possible to get a loan of another carburettor from a dealer or someone who has changed theirs for some other type (as some people change things which are working perfectly just for something to do) to find out for sure if it is the carburettor?
By Simplo
#67331
Thank you all for your replies.
As soon as possible I will look again for air leaks and try to clean again all the carb, including the side holes of the main jet (even I think there's only one).
Unfortunately I think mine is the only 350 in all Sardinia (except for a '87 one with a modified carb, but I don't know who is the owner now), so I can't try another carb :(
User avatar
By Adrian
#67347
I'm hoping you will find the air leak or blockage, but new VM24 Mikarbs can be had cheaply from India even with shipping. Probably shouldn't say this as our hosts have them for sale too! A.
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