PKW 24mm which baseline jets & needle ?

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johnny650
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Fri Nov 16, 2018 8:26 pm

finally given up on the jetex 22mm and ordered one of those cheap PWK 24mm OKO carbs from China .

I have searched the carburettor tuning section and not found any advice for this size carb
Has anyone used one of these on a 185cc and could give me some tips on jetting and setting up please.

I would like to order one of those jet and needle selection kits but it would be useful to know I'm ordering a range that will be useful.

nick b
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Sat Nov 17, 2018 12:14 pm

scootercenter quotes for the polini 24jjh needle 2nd clip 125 jet as a starting point I have rt 195 with a 28 polini and 2nd clip was spot on but I went down to 118 main [but I live in southern spain and jets react differently to high and low temps]

johnny650
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Sat Nov 17, 2018 10:26 pm

thanks Nick that gives me some idea where I should start .
These Chinese Keihin clones PWK OKO Koso etc come with a set of jets and needles but they are for a 50cc engine I think.
I will order up one of those 20x piece jet and needle kits and hope the range is close to what I need.
Cheers Johnny

nellyboyo
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Sat Nov 24, 2018 6:20 am

Off the top of my head mate , Ive set a fair few PWK`s up and if I can do it anyone can...
start with a 116 main and a 36 pilot and JJH mid clip...I`d say that would be rich and well safe . I think you`ll be lowering it from there

johnny650
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Sat Nov 24, 2018 11:22 am

nellyboyo wrote:
Sat Nov 24, 2018 6:20 am
Off the top of my head mate , Ive set a fair few PWK`s up and if I can do it anyone can...
start with a 116 main and a 36 pilot and JJH mid clip...I`d say that would be rich and well safe . I think you`ll be lowering it from there
thanks buddy thats very helpful.

I'm not concerned about setting up the carb ...............its more to do with which range of spare jets and needles to order from China. They are cheap as chips but its the shipping times that are the killer. Didn't want to wait 4x weeks and find that I have the wrong range of jets and needles.

thanks for posting your baseline settings it will give me a starting point ;)

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dapper
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Mon Nov 26, 2018 1:17 pm

Try Splat Shop. Their jets are the proper ones.
Compact Toolbox Flywheel Holder

johnny650
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Tue Nov 27, 2018 11:21 am

dapper wrote:
Mon Nov 26, 2018 1:17 pm
Try Splat Shop. Their jets are the proper ones.
thanks for the tip dapper but I always use a jet gauge and vernier guage to test all of my jets and needles whatever source they come from and whatever they have stamped on them . Trust no one and nothing is what it purports to be has always been my philosophy ;)

A jet is simply a brass screw with a precision hole drilled in it to allow for a precise flow of air or liquid . there is no difference between an expensive jet from a racing supplier and a cheap Indian jet off ebay providing they have the correctly dimensioned jet hole to meter the same amount of liquid or air ;)

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chris2470
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Sat Dec 01, 2018 8:51 am

There is a lot of good information regarding the set up of PWK carbs here:
http://www.duncanracing.com/TechCenter/ ... g-2015.pdf
Baseline suggestions look to be ball park, JJK-3 or 2nd clip, 120 & 38.
The main issue I've seen is fuel flow when WOT, there is a small nipple in the bottom of the float bowl, to stop the float bottoming out , this must be ground flat, or cut away inside a plastic bowl, otherwise fuel starvation does occur.
The needle and jets from Stage6 or BGM are good quality, and reliable.
Best Regards

Chris

johnny650
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Sat Dec 01, 2018 1:10 pm

thank you Chris that is very helpful information especially about the nib that needs removing from the fuel bowl.
When i have it dialled in i'll post my settings
all the best
Johnny

nick b
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Sat Dec 01, 2018 4:28 pm

mate the one thing I didn't say is scooter centre also said 45 main mine works mega no starvation when I was sorting the jets out my mate that is 20 stone hit 130k up a gradient the only issue I have is you need to turn off the fuel tap or you end up with oil stains on your drive/garage

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