Break In Proper carburetor tuning during break in.

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Hello everyone,
I would like to ask you about my problems with 80cc engine I have.
I am trying to break it in properly, as instruction says. I use 1:16 semisynthetic oil mix with 95 unleaded gasoline.
Problem is low top speed - about 20mph(30km/h). Engine starts four stroking above that speed. Second fact is that spark plug was dark and moist. Beacuse of these two things at about 60 of mileage i dropped needle in carbourator 1 notch up to position 2 to make mixture a bit leaner. Now, at 150miles it runs little faster but still starts to four stroke at given speed. Spark plug looks better, it's cleaner, but still little dark.

My question is - should I set the needle to middle- factory setting and finish break in perioid, and then start to think about tuning? I am afraid that engine is being damaged beacuse of leaner fuel-mixture, so it has worse lubrication.

What should I do?

 

[FurryOnTheInside]

150 miles is well past break-in stage. Switch to 32:1, then clean the air filter, or preferably upgrade it to one that isnt restrictive (won't effectively choke the engine at high RPM).

Having the needle dropped one notch below the middle won't do any damage. Actually, it is the most common needle setting.

You might want to get a smaller jet but I would wait until you have a great air filter first so you can see what that does.

 

[mcdanida]

If anyone is still following this, I am using 32:1 mix now and wondered the best carb pin setting! Closer to end (lean) or closer to middle (rich)? Thanks!

 

[DAMIEN1307]

f anyone is still following this, I am using 32:1 mix now and wondered the best carb pin setting! Closer to end (lean) or closer to middle (rich)? Thanks!

To me, that depends on altitude...im at a 4500 ft above sea level and have the clip at the very first notch on the top of the needle for the leanest setting and all is fine...whats your altitude where you are at ???...and where is it set right now...DAMIEN

 

[mcdanida]

Sea level and I haven't checked yet but will soon

 

[DAMIEN1307]

Sea level and I haven't checked yet but will soon

Let me know when you do check it so we know where to go from there...I know your MPG is a little off so thats what we need to know first...DAMIEN

 

[mcdanida]

Sure will. Also, next tank I am running 32:1. Gotta finish this one off which is like 20:1

 

[Frogslayer]

If anyone is still following this, I am using 32:1 mix now and wondered the best carb pin setting! Closer to end (lean) or closer to middle (rich)? Thanks!

You should really jet for full throttle then adjust needle position after you have the right jet.

 

[mcdanida]

Let me know when you do check it so we know where to go from there...I know your MPG is a little off so thats what we need to know first...DAMIEN

Question: talking lean/rich as pertaining to needle adjustment, do they mean the air/fuel mix? How is lean defined? Lean fuel mixture or lean air mixture? I am assuming lean fuel mixture obviously translates to better mpg if it's running good in that condition.

 

[HumanPerson]

Lean/rich should be used as referring to fuel/air ratio.
Fouling plugs is not a function of how much oil you run. If you are jetted properly (fuel/air ratio), you can run just about any oil ratio.
Kart racers run 16:1 and 20:1 with no fouling problems. I'm not sure what stimulated your questions, but I've always thought that the best advice for ratios is pick a good ratio (e.g., 32:1), and jet for it.

2 strokes can be ran lean in two ways.
If you are running to small of jets for the current climate and engine set up or if you run to much oil in your oil to fuel ratio you can run to lean as well. To much oil in the mix doesnt allow as much fuel which will cause it to run to lean as well. Running it to rich is just typically caused by to large of jets for the engine setup or current climate. Hope this helps neighbor!