So there is an IAT spark table that looks as if it will remove about 1.5 up to 5º of timing from 65ºC and above

OK, seems reasonable ...so why the hell are the logs showing my normal spark advance sat at idle increasing by about 10º around the 60~70 IAT

can't see why it would make a difference but no, I am not using a closed throttle spark table (or I'm not supposed to be anyway).

Spark table set at 17 for idle will rise to wobble around about 21~28, and if I have the tables at 20 it rises to 24~31

wots that all about then??

 

Do you have an Idle Spark Control gain table?
The description says adds this many degrees timing for each each 100 rpm idle error.

There is also an Idle Spark Control Max table.
It sets the max spark gain for the Spark Control gain table.

If you do not see the table with WinPV, make sure you have the latest PV Software and firmware versions. Run the PV Update Client with the PV connected to your computer.

After getting the latest firmware/software open your current tune, save a copy with a new name, open the new copy and choose from the PowerView menu - select Update Tune from PV, read the Upgrade Tune pop up and choose Yes.

This will update your tune with any new tables supported by the current PV Firmware.

I see these tables in the 2017 Sportster Power Vision tunes. They are HD software version 414 and my PV firmware Version is 2.0.261553

The PV Stage 1 tunes for 2017 Sportsters have a Idle Spark Control Max set to 6 degrees.

 

Nope ...fully up on the the idle gain and max controls and it's nothing to do with that.

This is a 358 config ...that no-one tunes, if that makes a difference

 

The 17 Sportster tune I looked at is a 414 software level. Sportsters are always behind

I asked Dynojet what would happen if I loaded a 374 software level file on my 176 software ECU. They said it would not work
It includes a lambda based tune and heated O2 sensors I don't have but that option could be turned off in the tune.

I haven't wanted to buy a new ECU so I haven't tried it!