Newer carbs now have an adjustment?

JBtoro

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I am looking to buy a new carb for my GCV190. To my surprise, I noticed that many (all?) now have a Pilot Screw. I have not bought a new machine of any type in over a decade so none of my Honda carbs have this. I suppose this allows for some adjustment but not sure what exactly, RPM's maybe? Any explanation will be much appreciated.

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Hammermechanicman

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I don't think that is an adjustment screw. It just covers the pilot jet.
 

Scrubcadet10

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I don't think that is an adjustment screw. It just covers the pilot jet.
i thought so too, but then i found this pic, generally the pilot jet is under that other flat head screw below the RPM stopper.
1606069341360.png
 

Hammermechanicman

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Yeah, looks like you're right. Not seen a chonda carb with that screw on the side
 

bertsmobile1

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you will probably find it is the carb for an engine that is sold in Asia that some one got a shipment of & is selling them on evilpay or Amazone where apparently EPA regulations don't apply .
Down here no new 2 strokes using a mix heavier than 40:1 can be sold in a shop.
Ebay has hundreds of old 25:1 two strokes for sale and if the stats are correct some of the models have sold near 1000 of them .
I , as a registered repairer can't buy the tools for adjusting any carb latter than a Tier I from my wholesalers but Amazone Aust sells kits for Tier II & Tier III to anyone
 

Born2Mow

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• Running engines need to meet emission specs. Individual parts do not.

• Every carb I've even seen had adjustments. It's just that the manufacturer has to hide them from the owner to meet EPA specs. This is usually done with a lead plug (or some such hiding mechanism) once the factory adjusts the settings.
 

JBtoro

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Thanks for the background. But what does the adjustment actually do?
 

Born2Mow

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But what does the adjustment actually do?
That totally depends upon the design of the carb. In the photos above it appears to be a idle mixture. Some carbs also have a variable main jet screw.
 

JBtoro

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Hmm, evidently nobody here has actually bought one of these carbs & adjusted it by turning that screw. I posted at another forum as well & got no responses. Yet, Amazon & ebay have dozens of offerings so people like us are obviously buying this style carb. Just saying.
 
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