air/fule mixture leak

[adi.barda]

Hello guys,
It's hard for me to properly describe the issue but i'll try:
when the engine is cold and i'm starting it - while warming it with but also without using the choke i'm getting some kind of "back-back-fires" an air/fuel mixture trying to explode out from the carbs up threw the hoses(rubber) connecting the air-box and the carbs.

when the engine is warm enough it doesn't happen again.

has anyone encountered such a phenomena - what can be done to prevent it?

Thanks a lot for your help

Adi Barda

 

[ninjaneer]

possibly an intake manifold leak.

• make sure the carbs are sitting on the cylinder securely and that their boots are creating a proper seal.
• do the same with the airbox.

possibly excessively lean air/fuel mixture that is burning too slowly/unevenly.

• a partially blocked pilot jet can may be the culprit. try peashooter and shotgun cleaning procedures.
• maybe insufficient fuel supply. make sure your fuel bowls are being filled. perhaps floats need adjusting or pump needs servicing.