Runtong dellarto clone vs CNS carb


New Member
Jul 21, 2019
Hey guys, I have a question

I have a skyhawk engine with expansion chamber and upgraded CDI. In terms of carbeurators, I have a couple nt carbs, a CNS, a RT dellarto clone, and a "speed" nt carb.

Right now I'm using the runtong dellarto clone and I have a few questions

1. How do I richen or lean it out? There's no needle or Pac man...

2. Why does it 4 stroke sometimes on top end or uphill

3. Is it me, or is the CNS carb WAY better than this one.

I tuned the cns perfectly and found it to be remarkable. It was powerful, smooth acceleration, overall amazing carb. I'm just not blown away by this RT carb like I was hoping. First off, the float is half the size as the CNS (a bit bigger than the NT) and second of all, I just don't find it to pack asuch of a punch as expected.

Am I missing something here??

Please help


Well-Known Member
Dec 29, 2008
Think you have to change jets to get right mixture to lean it out. 4 stroking is to rich, the rest you will have to wait till some else jumps in as i don't have a 2 stroke yet..............Curt

Jimmy Bloodmaker

Active Member
Nov 24, 2018
i like the dell clones. easy to set. i set mine so they don't 4 stroke going up a hill. other then that i'm gonna get a bit of 4 stroking when staying at speed or decelerating, or just accelerating slowly. i like running it like you would set a chainsaw. bit rich on the bottom, but sweet as silk when load is applied. i found setting it one jet size over perfect run is best for me. the reason being, a the load applied as i said above, and b it keeps my engine cooler and producing more power during long or hard accelerations.every single one of these i blew up was from not enough fuel ( 2 stroke, running to lean). stick with the dell clone and set a bit rich. if you can over rev your engine while it is sitting on the stand clutch held disconnected, you're running to lean. just my two cents. easy way to set your carb, on the coldest of cold days, set it so it runs good. then in summer you know you have enough fuel to keep it running cool.

oh and to get better performance out of a dell clone, you can file on the slide in the carb. different shapes do different effects. i just leave mine a bit rich on the bottom end, runs really well on the top, but some sputter down lower.