Mixture screws

[MarkCR750]

It’s so long since I have adjusted my PD42’s that I have actually forgotten if they are air or fuel screws!, there’s conflicting answers on google but I’m reasonably sure they are fuel being on the engine side of the slides, so clockwise is weaker and anti-clockwise is richer, am I right?, cheers Mark.

[Bryanj]

All i remember is do not tighten them too much of the tiny tip gets damaged and they need the washers and O rings to be in good order

[K2-K6]

It’s so long since I have adjusted my PD42’s that I have actually forgotten if they are air or fuel screws!, there’s conflicting answers on google but I’m reasonably sure they are fuel being on the engine side of the slides, so clockwise is weaker and anti-clockwise is richer, am I right?, cheers Mark.

I've got it the some as you note above.

Even the workshop manual from Honda doesn't say which way it is  !

These work on fixed air volume into idle circuit and via emulsion tube mix (no screw adjustment provided) set by the fitted jets.

The final adjustment being modulation of the total mix from above point. Anticlockwise exposes that whole idle "system" to more intake vacuum, ultimately to flow more fuel from same vacuum, with clockwise effectively delivering less to the same vacuum.

Workshop manual start point is 1 1/2 turns out from closed for K7 with std intake. It doesn't ask for all to be set identically, but individual on a cylinder by cylinder basis.

[Bryanj]

I do have a scan of the F2/3 K7/8 manual but the original was never a good thing to read from Honda, not sure if i gave Ash a copy to load up to his drop box, i will happily copy the dvd but dont expect it soon as i am in the process of turning my "study" aka shit pit into my wifes craft room so everthing is in cardboard boxes yey to be sorted!!!!!

[MarkCR750]

It’s so long since I have adjusted my PD42’s that I have actually forgotten if they are air or fuel screws!, there’s conflicting answers on google but I’m reasonably sure they are fuel being on the engine side of the slides, so clockwise is weaker and anti-clockwise is richer, am I right?, cheers Mark.

I've got it the some as you note above.

Even the workshop manual from Honda doesn't say which way it is  !

These work on fixed air volume into idle circuit and via emulsion tube mix (no screw adjustment provided) set by the fitted jets.

The final adjustment being modulation of the total mix from above point. Anticlockwise exposes that whole idle "system" to more intake vacuum, ultimately to flow more fuel from same vacuum, with clockwise effectively delivering less to the same vacuum.

Workshop manual start point is 1 1/2 turns out from closed for K7 with std intake. It doesn't ask for all to be set identically, but individual on a cylinder by cylinder basis.

Thanks, great answer 👍

[MarkCR750]

I do have a scan of the F2/3 K7/8 manual but the original was never a good thing to read from Honda, not sure if i gave Ash a copy to load up to his drop box, i will happily copy the dvd but dont expect it soon as i am in the process of turning my "study" aka shit pit into my wifes craft room so everthing is in cardboard boxes yey to be sorted!!!!!

Thanks Brian but I have now found my manual 👍

[Bryanj]

No problem mark, i found the original honda manual looked like a photocopy to start, nothing like the uality of the older ones