How do I know if my premix ratio is correct?

[codeman26]

So I finally got around to converting my ride to premix. Started off with a slightly heavy 32:1 ratio (maybe an ounce more than exactly 32:1 in 1 gallon of gas just to be on the safe side of things). I also increased main jet size from 98 to 100. My question is; what signs do I look for to know if my premix ratio is lean or rich? Color on the plug? smoke?
Running an Athena mid-race kit and Giannelli reverse pipe.

[captincvmn]

I do 4oz to a gallon of gas. Everybody here will do something slightly different.
I do know that more oil means less gasoline and will affect jetting.

[ryan_ott]

Here is your best friend for correct mixing.
Everyone will have their own preference but really depends on quality of oil and what your engine needs. Most will run 32-40:1

[geoffh]

There's an oil ratio calculator over there<< on the left captaincvnm is spot on for 32 to 1,assuming your talking U.S. gallons and U.S. ounces ,it,s all Greek to us Brits.

Geof

[codeman26]

I fully understand HOW to mix a proper ratio, race plenty of motocross in my days. As stated in the replies to this, everyone will run a little different ratio. My question is "What are the visual ques" or any other signs that I would look for to see if the ratio is CORRECT? If it's too rich, what signs do I look for? If it's too lean, what signs do I look for? 

[geoffh]

I see what you ask,it,s down the art of plug reading/butt dyno stuff I read lots techno stuff but I just see a tan color on my plug and call it good.

Geoff

[aeroxbud]

I would not of thought you needed to go beyond 40:1. That's what most of the higher end stuff seems to run. More importantly would be the quality of oil you use.
If you run too much oil, it will smoke excessively. Leave lots of oil deposits and will gum up the rings.

[codeman26]

Ok, makes sense. My first batch of premix was probably close to 40:1. I'll drop it down to an exact 32:1 and revert to the previous pilot jet. I increase both pilot and main by 2 sizes to account for the premix. Plug is pretty black. I'm just not sure if it's from too large a pilot jet, premix ratio or if the needle needs to go down a notch. It stutters at low RPM then cleans out real nice in the upper RPM's Continue experimenting I guess.

[snaker]

If you compare the extremes of oil quantity:

Too much oil:
smoke
carbon buildup
possible need to eventually open up the engine and clean/freshen

Too little oil:
oil starvation
damage

I think the safest bet is to lean towards the heavier oil specs when unsure.

There is usually a range that will be just fine.
I recall my chainsaw manuals and others usually giving recommendations.
Don't have handy but I think both Husqvarna and Sthil called for 50:1 for their brand oil and to use 30:1 of other brand oils.

I also remember back in the day when 20:1 was a pretty normal spec.

That is pretty telling on the workable range.

[captincvmn]

20:1? Smokin!