lean idle

[mauricejota7604]

A question for the cab experts I suspect I may have poor sealing on the connection between the dellorto carby body and the nylon or plastic sleeve that connects to the inlet stub. and as a consequence lower vaccumn at low engine revs.
This is on an early head with the rubber tubes and they are sealed up perfectly. I have to richen up the idle mixture to hold get a good idle or it spits back a lot but then the transition to the pilot jet is bad. Compression, valve clearances ignition and cam timing is spot on.
Has anyone had issues with these plastic sleeves leaking between the inlet manifold or carb body and how in the hell do you get them out???
Regards,
Maurice.

 

[sfcpiet]

A question for the cab experts I suspect I may have poor sealing on the connection between the dellorto carby body and the nylon or plastic sleeve that connects to the inlet stub. and as a consequence lower vaccumn at low engine revs.
This is on an early head with the rubber tubes and they are sealed up perfectly. I have to richen up the idle mixture to hold get a good idle or it spits back a lot but then the transition to the pilot jet is bad. Compression, valve clearances ignition and cam timing is spot on.
Has anyone had issues with these plastic sleeves leaking between the inlet manifold or carb body and how in the hell do you get them out???
Regards,
Maurice.

No need to normally.  Usually quite difficult to remove without damaging them.

Check the carb bodies for cracks radiating out from the clamp slots.  These can be barely visible.  Short ones are usually sealed off by the plastic insert, the longer ones can reach right up to the mixing chamber.

piet

 

[breganzane]

Plastics generally have a much higher coefficient of expansion than aluminium, so if you stick the plot in the freezer you'll find they come out much easier.