Diagnosing an engine and retuning a carb?

Cisco

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I was convinced that lean was running with too much oil and rich was too much gas
Your fuel mix can be rich or lean; 16:1 is rich and 32:1 is lean. Your carburetor can run rich or lean too depending on jet size and needle height. It can be confusing. Proper mix and proper fuel load are what you are trying to achieve.
 

DistantWolrld101

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let me make a A** of my self and assume your in the U.S are you in a mountain region like AZ and NM or you in a state that's close to sea level like Mi and Fl
 

Cisco

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I live at about 3200 ft elevation, so my NT carb ran a little rich at stock setup (needle setting and jet size). Raising the needle clip up a notch dropped the needle down enough to lean the fuel load from idle to about half throttle. After that it's up to the main jet to meter the fuel load. I didn't reduce the jet size because I need a rich fuel load at full throttle to climb these hills.
 

Emcee

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Your fuel mix can be rich or lean; 16:1 is rich and 32:1 is lean. Your carburetor can run rich or lean too depending on jet size and needle height. It can be confusing. Proper mix and proper fuel load are what you are trying to achieve.
So even though we could use the same plug, same engine, same carb, we could all achieve different results based on quality of gas, altitude, imperfections in manufacturing, type of oil and temp/humidity?

How you say 32:1 is lean, should I bump it down some?

I have a unused Chinese POS spark plug that came with the kit. I'm considering doing the plug chop tomorrow just to work with a fresh canvas. I would hate to dirty up that slightly used NGK plug.
 

DistantWolrld101

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your elevation area is 100ft above mine

i ran my clip in the middle

ratio 32:1

NT carb i put 3 holes in the plastic or in the eyes of @Cisco one GIANT HOLE :p
full


you can start with this and move from there since your elevation is close to mine
 

Cisco

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These NT style carbs are very simplistic, even crude. There is little that can be adjusted. Changing your fuel mix and needle setting is about all you need to do to get it in tune. Hold off on jetting until you are sure everything else is right (fuel, compression, ignition). Intake air leaks are something to be concerned about, especially after removing and adjusting the carb several times. Be sure there is an O ring in the throat of the carb to seal against the end of the intake. Make sure the carb is pressed snugly against the intake when tightening the clamp. Do not over tighten the clamp. The clamp does not seal the carb to the intake, the O ring seals the carb to the intake. The clamp just holds it firmly in place.
 

Cisco

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32:1 mix is lean-ish. I think it's a good ratio, and I use petroleum-based mix oil. Some people run synthetic mix at 40:1 or even 50:1. I think that's too lean, just my opinion.
 

Emcee

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So here's the plug. I'm assuming too rich? Also, I found a 1 gallon gas container for $3.00. No more mixing gas in my tank 😇
 

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Chainlube

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Looks like you were putting in 2L worth of oil but only 1L of fuel. Blow or wipe the oil off your plug, mix up a fresh can of fuel and try again.
 
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