What jets and needles do i need for 28mm PWK carbs

[Tobyjugs]

Hello Chaps. My standard Mikuni's can't feed enough premix to my engine. I have decided to use a pair of 28mm PWK's. Can anyone advise me on which type of needle, jets and slide, etc i should use.

It's for use with a tuned 4LO  engine using pod filters.

[bare]

Pod filters means Big jets. No idea what size to suggest though.
Although 'on Here' Jet sizings (postings) seem to me to be inordinately large.
No idea why though
Can suggest Not futzing about with slides as that's a can 'o worms best left alone.

[Tobyjugs]

I've seen the same type of carbs for sale with different spec slides so i need to make sure i have the right ones for an rd

[midlifecrisisrd]

I need to check what's in my new ones

My used ones are 3.5 slide and jjh needle but that's ypvs and airbox

Think if you are running pods n68 needles are required

Think the 4 slide needs n99 needles

From memory lc needs a bigger pilot and smaller mains than ypvs but pilot affects whole range

You are probably looking at 50 pilots and 155 mains as a starting point

Ypvs usually around 42 and 152

Steve

[marsbar350]

on my LC 350 have 135 mains and 40 pilots no airbox lid
but that was with Kenny pipes fitted

[Tobyjugs]

Thanks for the info chaps. The bike is running Pods and a set of kenny's finest.

[marsbar350]

Apr 22, 2018 19:32:52 GMT 1 Tobyjugs said:

Thanks for the info chaps. The bike is running Pods and a set of kenny's finest.

when mutts sees this post he might be able to help out
lots of the Yorkshire types having differing set ups

[Tobyjugs]

Can anybody explain the N68 needle as i can't find the spec. I have JJH needles. Is the N68 a certain type of JJH needle?

[rigga]

N68 was apparently the ones fitted to pwk28's fitted to Kawasaki kr1s, think these worked well but are not available anymore, jjh are the ones now recommended to use, no idea how they compare to N68 versions, there is a N68a available from Allen's which I've just purchased, but not tried as yet.

[wallcraft]

Apr 22, 2018 19:26:55 GMT 1 marsbar350 said:

on my LC 350 have 135 mains and 40 pilots no airbox lid
but that was with Kenny pipes fitted

What needles and slide cutaway number are you running with those jets?

Mark.

[midlifecrisisrd]

Jul 2, 2018 10:11:52 GMT 1 Tobyjugs said:

Can anybody explain the N68 needle as i can't find the spec. I have JJH needles. Is the N68 a certain type of JJH needle?

As rigga says the N68 seems to be a Kawasaki specific needle on the Kr1

Steve

[Tobyjugs]

Thanks for the help lads

[Tobyjugs]

Time for another question;

How are you chaps synching your PWK's?

I resorted to the finger method, followed by a check with a photo.

The lolly pop stick method sucks or maybe i need to eat some other type of lollies?

[stusco]

Lollipop method for me the original style not a magnum type stick

[Tobyjugs]

Hmm mine both fell out after 3/4 throttle

[stusco]

If they both move at the same time they are in sync there’s nothing you can adjust at wot

[Tobyjugs]

I think i will have to make some special WOT lolly pop sticks.
I believe full throttle is a very important place to have your carbs sync'd.
After all that's where they are set on the Mikuni's.

[rigga]

Yes lolly stick to check synch at just off idle, so rising at same rate, then a mirror to see both slides at full throttle.

[bare]

Full throttle is easily Eyeballed with the engine off.
Idle or slightly above it is the worst case for equal slide position , equal suction..
Sooo it's Clever to set slides at the same start position.
All else follows.