Carburetor Jetting/Mixture Question

[mxchris727]

Hi, just a quick question....
What is the difference between the carburetor jetting and the fuel/oil mix ratio?
As I understand, the jetting is how much fluid enters the engine and the mixture is the composition on the fluids? How does this affect the rich and lean running conditions?

Thanks,
Chris

P.S. I use a 20:1 ratio for break in and 24:1 for regular riding. Is this correct?

 

[mxchris727]

So then why do people adjust the jet if they can just change the ratio mixture? Also, wouldn't using a 100:1 ratio overheat the engine?

 

[dan+1]

looking at where these things come from I was thinking the low grade fuel china has is why the jets are larger. Example right now at break in I am running 16 to 1. wanted plenty of lube in there for the first little bit. Anyway this thing is running great, no folus, cranks easy with 1/4 choke on a chilly morning maybe a little push on the primer button but peddal up to about 4 mile an hour and she kicks right off.

I know when I change my ratio I will need to reduce the jets unless i change the breather and exaust up then who knows. But ain't that the fun part tinkering with um.

 

[mapbike]

Yep.............! it tizz...

looking at where these things come from I was thinking the low grade fuel china has is why the jets are larger. Example right now at break in I am running 16 to 1. wanted plenty of lube in there for the first little bit. Anyway this thing is running great, no folus, cranks easy with 1/4 choke on a chilly morning maybe a little push on the primer button but peddal up to about 4 mile an hour and she kicks right off.

I know when I change my ratio I will need to reduce the jets unless i change the breather and exaust up then who knows. But ain't that the fun part tinkering with um.

 

[Hammond Egger]

When you change from 16:1 you won't believe how much better your motor runs.

 

[gubba]

i love guys who run 100 to 1 oil mix........i make good money replacing froze up motors.
i include the first gallon of fuel and enough oil for the second gallon at 16 or 18 oz per gallon so i know they are are running a good breakin. after that i advise 25 to 1 (5 oz per gallon) synth oil.
the only froze up motors i get back is when they follow the lawnmower shop's advise that any 2- stroke only needs 2 oz per gallon.
i sell them a new motor only.

stay dry
gubba

 

[DuctTapedGoat]

25:1 synthetic is way too much oil.

You can easily run 32:1 dino, and synthetic you can bump that up to 40:1.

 

[2door]

i love guys who run 100 to 1 oil mix........i make good money replacing froze up motors.
i include the first gallon of fuel and enough oil for the second gallon at 16 or 18 oz per gallon so i know they are are running a good breakin. after that i advise 25 to 1 (5 oz per gallon) synth oil.
the only froze up motors i get back is when they follow the lawnmower shop's advise that any 2- stroke only needs 2 oz per gallon.
i sell them a new motor only.

stay dry
gubba

Gubba,
Maybe take an hour or so and read this> http://motorbicycling.com/f3/100-1-mix-9850.html

I've been running Opti-2 @ 100:1 in three bikes for a long time and many miles, some of them pretty darn hard. Haven't blown or seized a motor yet.
Tom

 

[mapbike]

many people run 100:1 amsoil & opti 2 with many many hard miles and never a single issue.........i run opti @ 70:1 myself.

Walmart cheapo oil at 100:1 yeah big mistake........