Hello all:
So I purchased some carbs off ebay which were pwk 30mm keihins. They were I believe originally distributed thru Sudco international here in beautiful so cal.
When I set the needle clip in the middle position I got really horrible spudder in the mids. I had to jet the main down to 130 from 140. I ended up adjusting the clip to 2nd from the top and that seemed to have solved the spudder. The main jet however I kept at 130 since i couldn't rev out cleanly. I looked at the needle and it was unmarked but I assumed it was the same as JJH. Ordered some JJH needles thru treatland since I was unsure. I took some measurements with a micrometer and compared and realized dimensionally they were slightly different in taper/diameter and length. I put the JJH needles from treatland in and put the clip in the middle and installed some 140 mains. This setting seemed to be optimal and on top end it doesn't spudder and run flat like with the 130 mains.
I guess my point to all of this is to never assume these cheap carbs all have the same parts especially if they are unmarked. I am not sure if the ones I purchased thru ebay were replicas? I have no idea these days.
Good to hear a real-world review of the ebay knock-offs compared to genuine.
Thanks!
yup. thats exaclty what it was a decent copy but def not 'legit', same situation on my 72 w rd motor. 38 pilot,jjh needle middle, 142 main.
Yeah. I figured this would help out some folks here. If people decide to go with Keihins and instead of mikunis, there is an alternate with some data here. In my case, the mikunis were worn out and warped. New ones couldn't be shipped to ca from Dennis Kirk. For 60 dollars, a set of chinese copies why not right? I guess only time will tell if they hold up.
140 main jet
42 pilot
JJH needle clip on third slot
1.5 turns out on airscrew
Foam UNI filters
73 RD350 motor with vitos crank. Stock porting with ebay cylinders with RD400 prox pistons. Stock reeds and manifolds no crossover tube. Spec 2 classics and HPI ignition no battery. About 500 miles on this motor no issues.
Gotta love treatland and their stocked products. Been buying from them for years for my moped and other 2 stroke supplies.
Although Sudco is out of business their website is still up
Keihin and Mikuni: Genuine vs Fake Carburetors (https://www.sudco.com/genuine_vs_fake_carburetors.html)