CV-40 Carburetor Port question

[rageglide]

Thanks FSG for the cut away!

crazyjoe, as you said, the bigger the pilot = richer the slow and idle circuits will run.  They are fed from the same jet,the Mixture screw allows dialing mixture down or up to obtain a nice clean idle.  If you need a bigger pilot for a nice clean transition and low speed running, the Idle mixture will probably be too rich if you were to leave it at the same setting that works best for a smaller pilot.  The relationship between the pilot and mixture screw is a balancing act where going up on one will require going down on the other.

If you have too big a pilot the engine can idle off the transfer ports with the mixture screw turned all the way in.  If you put in a very small pilot jet you'll have to open the mixture screw as far as you can to get an idle.  That's an extreme example of the relationship.

If you put in a 40 jet like you mentioned in your other post, you would need to open up the mixture screw further to get enough fuel to idle...

Sorry if I'm not able to explain this clearly... I didn't do well in grammar while in school. :-)

Proper Carb tuning involves adjusting to get the mixtures correct, not just opening up a mixture screw to a pre-determined number of turns.  Every engine, especially with cam changes, will have different requirements.

[FSG]

[crazy joe]

So to get want I want (get that screw at about 2.5 turns)
would I put in a bigger Pilot Jet or do I have to change both
Pilot and main Jet?

[Hogman]

So to get want I want (get that screw at about 2.5 turns)
would I put in a bigger Pilot Jet or do I have to change both
Pilot and main Jet?

PILOT

[rageglide]

haha what Hogman said.  Pilot.  Don't over think this.  Put a 45 in there and fiddle with the mixture screw until you have a good idle and start riding.

[crazy joe]

Ha!!!  Rageglide That's what I'm going to do after you explained it : )
It kinda makes sense.... 

[rageglide]

LOL... end goal = riding 

[01fxdxt]

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