PWK 28 mm Kehin Copy.

[epod]

Gday all, I have just been setting up a PWK28mm Kehin Copy and I was wondering if anybody is using one. I thought It would be the same as OKO 28mm I have set up in the past but this kehin does not have any sizes printed on the jets. It seems to want a leaner pilot jet but I am wondering what the stock size is.
Ride on.

 

[Cactus Jack]

What brand is this carb ?? A KOSO ? Or one of the PWK copies from a guy overseas (can't remember who he was but he reckoned his carbs were genuine PWK's ... when they weren't because they didn't have the proper float bowl with the removable screw cap) ...

Your best bet is to simply buy keihin jets in the sizes you know work OR go by what other people are using in their 28 mm OKO's ... that is ... IF the carb you've got takes Keihin type jets .... the only other way to work out the size of unmarked jets is to check the holes with jet drills ... then look up on a jet size chart to see what numbered jet they match ...

Here's some info on the PWK's float level ...


SETTING CORRECT FLOAT HEIGHT
Before changing any jetting parts, check the carburetor for the correct float height. Measure the height from the bottom of the float to the carb body gasket surface (where the float bowl mates with with the float bowl removed). When checking the height , the float should be resting on the float needle pin (but NOT depressing it), this can be accomplished by holding the carb body at an angle until the float tab rests against the float needle pin. If adjustment is needed bend the metal on the float arm until the correct height is achieved.

Float Heights for Keihin Carbs
PWK 28 = 19mm
PE 24 - 38 = 14mm

 

[NRG]

Becareful with Jet sizing from china to Japan, they dont match.

For example: china 120 = Japan 180 main jet.

 

[themountain]

Becareful with Jet sizing from china to Japan, they dont match.
For example: china 120 = Japan 180 main jet.

WHAT..??....are you serious??

 

[epod]

Hello all

Thanks for the float height info, that is very handy. I discovered the jets in it are quite large a 138main and 42 pilot. I figure it will work fine with a 105 or 110 main and a 38 pilot. The float height is good.
China jets are know to be around one size or smaller than there number. My friend has measured them compared to jap jets. I don't know where the other guy got his info.
Peace. Ride on
P.S Built an awsome track yesterday at Native Dog Snowy mountains Jindabyne moto park hoping to open to the public in early 2009.

 

[tormentandglory]

Some jets are measured by their hole size, others are measured by their flow rate, so the numbers don't always mean much when comparing jets.

I have a stack of chinese carbs in my garage, mikuni/keihin rip-offs, flat and round slide. Most of them have no jet markings. Very annoying. Only one of them has a needle and seat that actually works (a molkt 26mm round slide). All the others piss fuel straight onto the ground. But there are no pilot jets available to suit the molkt so my bike runs **** anyway. Grrr!!!

 

[themountain]

well....so for all
Mikuni jets are measured by flow rate
Keihin are diameters
nothing to do with ***** or notchink....lol

Once there was a comparation chart here somewhere...can´t find it, sorry

 

[Cactus Jack]

What I find strange is that people on PM reckon they're running 155 to 210 main jets in 26 mm Mikuni carbs ... at sea level ... (above sea level requires smaller jets) ... If you check with the chart below you'll find the sizes they say they're running to be huge when compared to Keihin sizes ... An 80 HP ~ 500 cc JAWA speedway bike engine running on methanol only uses a #235 main ...



Width------Keihin # -- DynoJet # -- Mikuni #
0.0350---- 92.5--------- 92---------- 86.3
0.0360---- 95----------- 94---------- 88.1
0.0370---- 97.5--------- 96---------- 90.0
0.0380---- 100---------- 98---------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5

 

[themountain]

yop ..a friend once got because of that a 180 in his VM and thought it would be the shizznit...hahaha...was thast a surprise when the bike run even better whenI rejet the carb!!

 

[Cactus Jack]

Ha Ha Ha ... it would have ran like a gutless soggy dog with the equivalent of a #217.5 Keihin main jet in it ...