PWK Carb?

[BoostedBaja]

Have any of you guys tried the PWK 32mm on a predator 212? They seem to be much cheaper than a minuki. Cant seem to find an adapter, if one is needed.

---------- Post added at 10:32 AM ---------- Previous post was at 10:27 AM ----------

Correction: PWK clone

 

[bob58o]

32mm is huge for a 212.
I use a gx390 carb.
Some use 22mm Mikuni's/knock-offs.

I'm gettting a 32mm PWK knock off for my 420cc.


How modified is your 212cc?

Stock carbs flow around 45cfm if I think.
Stock heads flow around the same.
http://karting.4cycle.com/showthread.php?43425-Head-flow-CFM-numbers&

02-01-2015, 08:04 AM #8
youngengines
4 Cycle Advanced User
Join Date
Oct 2013
Location
Henry Va
Posts
1,381
I have two stock Hemi head numbers in front of me and a rtc6
Hemi #1
.100-35
.150-43
.200-45
.250-45
.300-45
.350-44.5
.400-coil bind
Hemi #2
.100-33
.150-43
.200-48
.250-49
.300-50
.350-51
RTC6
.100-35
.150-48
.200-53
.250-55
.300-56
.350-58
.400-59
Stock Ruxing carb -44cfm
All flowed @28inches



Most engine cfm calculators will say you need less than 30cfm for a 212cc engine running at 9000 RPMs. Less than 20cfm at 5400 RPM.
http://www.csgnetwork.com/cfmcalc.html



I like the gx390 carb on my 212 with Black Mamba Jr cam.

 

[BoostedBaja]

It isn't modified atm. Just looking at what carb to get with my other parts, as now I have a stock carb with a small jet. Was gonna get a flat top hemi piston, cam(BMjr), valve springs, con rod, and do some port work on my current head. Looks like they have a 30mm opton aswell

 

[KartFab]

Just as an FYI with carbs, they operate on the venturi effect to draw the correct amount of fuel to be mixed with the air.

If you get a carb that has a much bigger venturi than the stock diameter venturi, the flow at the point of the jet can be slowed to the point where the fuel will not be drawn out as effectively, and you get a lean condition. Rejetting the main jet as well as the pilot/idle jets may be necessary if you do this. Even then, the engine may not run well within a certain rpm range (may suffer at the operational rpms, and only run decent at very high rpms).

Point being, bigger carb doesnt always equal better. Right size carb for your RPM application is what you should go for.

I was told that you should go for a carb venturi that is 2mm smaller than the intake valve diameter as a rule of thumb.

 

[Jfive]

I'd buy a 22mm. I bought a carb filter and intake for 25.00 shipped.