PWK tuning

[quocle603]

Figured I would document my tuning progress for current and future tuners.

1975 RD350
Stock bore
DG heads
HPI ignition 1.8mm btdc
Yboot with uni filter
Banshee intake with crossover tube
Stock reeds
Oil injection
Spec II Pipes

Oko pwk28
Pilot jet 42
Airmixture 1.25 turns out
Needle jjh - position 2.5 (m4 washer)
Needle jet 8 holes
Main jet 148 (could try a 145)

Bike runs pretty well. It can rev quickly towards the powerband and seems to hit pretty hard around 5.5k+ rpm then pulls aggressively. It does seem to be a bit flat and rich before the powerband kicks in. Will mess around with the needle position more to see if it clears anything up.

[m in sc]

yeah. don't be afraid to use the leaner needle positions. the pwks tend to carry the pilot circuit further into the midrange than the TM or vm mikunis  0.02

[85RZwade]

Good information, thanks for posting

[quocle603]

Hoping to see if it improves with the leaner position. I have a feeling that it will. The pilot system seems to pull well, I was afraid to switch needle position to lose the lowend power.

I know there's a tuning spreadsheet but with these pwk carbs being such an affordable option and great results, I figured I could provide my personal run on them since installing them years ago.

[350GUY]

This is very good info. Thank you Quocle603.
Perhaps it's a good idea to have this in Tech Library.

[quocle603]

Lot of the help support has been from Mark. Starting point of 42 pilot, main jet 150, jjh needle is a great start.

I will be documenting things and hopefully it will be finalized for people to use as a basis and start tuning for their own needs.