CNS vs Dellorto SHA 15.15

Discussion in 'Performance Mods' started by Motocruiser, Jun 7, 2011.

  1. Motocruiser

    Motocruiser Member

    So my Dellorto SHA 15.15 doesn't have nearly the balls that my CNS carb has. The top speed and throttle response are affected. The CNS is more reaponsive. Do you think it's time to up jet the Dellorto? Or do you recommend a larger carb in general? It has a #68 main jet as of now.
    Last edited: Jun 7, 2011

  2. geebt48cc

    geebt48cc Member

    Yes, I know for a fact that you've got to be talking about the the V1 CNS. See, the V2 is nothing but a paper weight. I've heard that the CNS V1 is awesome, but the V2 I got with my 2010 Skyhawk kit was different CNS than the V1 like you are talking about.

    I'm just looking at the CNS V2 on shelf. Bummmmmer................My old Speed NT is pulling on......
  3. SlugMan

    SlugMan Member

    Sounds like ya just need to find the correct main jet for your local atm pressure. I have the SHA 15.15 carb on my 66cc Grubee, and it works great. Truth be told, this carb is kinda pricey, but works nicely. I ended up going down to a #64 5mm main jet. I'm @ sea level, on the coast of Maine.
    I would not recommed it for stock engines, it's 'almost' to big.
    I found out my restriction was air, not fuel. Just for fun, take off the air filter and cover. Does it run better? If so, you need to go down in jet size, or allow more air to flow through the engine. Going up is not always the answer, you are seeking the correct mixture.
    I ended up taking the air filter out, and drilled small holes in the cover for less restriction, made a big difference.
    Sick Bike Parts sells the 5mm jets. I'm pretty sure that's your problem. If the CNS carb works good, the SHA should work better once dialed in correctly.
    Good luck