Slow running speed during warmup.

[mleadbeater]

hi,

Yes, Niall, I think getting all butterflies to close is a good step, I have tried this when balancing air flows, my feeling is that the spindle closure springs are inadequate, when recently I fitted a stronger main return spring, i immediately achieved a much lower idle rpm.

Thanks to finding the Lucas manuals,( thanks Mike C)  I am making good progress on getting a basic understanding of the workings of the PI system, I think I am around 60% there, understanding what is happening inside the regulator has made me realise that there is, in theory, full variability of fuel mixture control, and that poor pickup on acceleration is not a feature of the PI system, and that hopefully there should be an easy cure, as michealfinnis suggests it shouldn’t be a bogging .

Will keep you posted on my findings, all good stuff,

Mike

[stuart]

Also make sure the bodies are all fitted level by using a straight edge. then balance them using a sync meter.

Stuart.

[mleadbeater]

Thanks Stuart, can you please expand a little your phrase on "bodies fitted level",  level relative to each other or what, why is this important and where do I mount a straight edge? If not level, what should be adjusted.
 

Cheers

 

Mike

[stuart]

3 hours ago, mleadbeater said:

Thanks Stuart, can you please expand a little your phrase on "bodies fitted level",  level relative to each other or what, why is this important and where do I mount a straight edge? If not level, what should be adjusted.
 

Cheers

 

Mike

The bodies should be level right across the head i.e. level with each other so that a straight edge can be placed across all three. There is a special tool available but its not rocket science to just use a straight steel rule etc to determine it. The bodies do have a certain amount of wriggle room on the mounting bolts and often the locating dowels are missing too. Its important so they match the inlet tracts the same and so the linkage can be correctly set.

Stuart.

Edited November 3, 2023 by stuart

[mleadbeater]

15 minutes ago, stuart said:

The bodies should be level right across the head i.e. level with each other so that a straight edge can be placed across all three. There is a special tool available but its not rocket science to just use a straight steel rule etc to determine it. The bodies do have a certain amount of wriggle room on the mounting bolts and often the locating dowels are missing too. Its important so they match the inlet tracts the same and so the linkage can be correctly set.

Stuart.

gotchya, Thanks.  Mike