I inherited a Rancher 50 20" chainsaw from my uncle only noone know the oil gas mixture.

50:1 that's 2.6 ounces of 2-stroke oil (preferably with fuel stabilizer) to one gallon of gas. I recommend using 89 octane gasoline for all small engines. It has little or no ethanol in it, as opposed to the 10% typical in 87 or 86 octane fuel. This will prevent a lot of fuel issues, especially if you are not using the tool daily or at least weekly.

Hi, bring the hi speed mixture screw out approximately one eighth of a turn and retry. Hope this helps, regards Phil.

My Husky 55 with a date of 2000 is 50 to 1.

I'm sure the separate oil tank is for the chain... you'll need to mix the gas with 2 cycle oil... typical ratio is 40:1 to 50:1...
Manuals are going to be real scarce... you may want to check with a local small engine repair shop to see if you can copy something they may have...

50: 1; You can download an OM here:
HusqvarnaUSA.com
http://www.husqvarna.com/us/homeowner/support/download-manuals/
Enter the 3 digit model number (no XPs, Es, just the numbers)
Serial number decode – useful when downloading IPLs and Manuals
06 1500198
06 = year produced – 2006 (single digit before 2000; please contact Husqvarna for single digit clarification http://www.husqvarna.com/us/homeowner/support/customer-support/)
15 = week produced – March
00198 = 198th unit Husky produced that week

Oil Mix Ratio:
The following ratios have been recommended for the last 10-15 years and is what Husky suggests for your saw..
Dolmar, Echo, Efco, Homelite, Husqvarna, Jonsered, Makita, Oleo-Mac, Red Max, Ryobi, Shindaiwa, Solo, Spear & Jackson, Stihl & Tanaka; all recommend 50:1.
• 1 gallon of premium fuel to 2.6 ounces of quality 2-cycle oil.
• 4 liters of premium fuel to 80 milliliters of quality 2-cycle oil.
McCulloch, Poulan & Wen; recommend 40:1.
• 1 gallon of premium fuel to 3.2 ounces of quality 2-cycle oil.
• 4 liters of premium fuel to 100 milliliters of quality 2-cycle oil.
Chinese chainsaws recommend 25:1.

If you have more questions or need additional help please reply below and I will get back to you. HTH & Good Luck.
Lou
Thank You for using FixYa.

Husqvarna recommends 50:1 and has for many years. 1 gallon of premium fuel to 2.6 ounces of quality 2-cycle oil or 4 liters of premium fuel to 80 milliliters of quality 2-cycle oil.

If you have more questions or need additional help please reply below and I will get back to you. Thank you for using FixYa and Good Luck. HTH
Lou

Mine are marked "L" & "H". Yours too? They are carburetor mixture adjustment screws.
Lou

Find an Operators and an IPL here:
HusqvarnaUSA.com
http://www.husqvarna.com/us/homeowner/support/download-manuals/
Enter the 3 digit model number (no XPs, Es, just the numbers)
Serial number decode – for use with IPL
06 1500198
06 = year produced – 2006 (single digit before 2000)
15 = week produced - March
00198 = 198th unit Husky produced that week

Fuel ratio 50:1 = 1gal premium/2.6oz quality 2-cycle engine oil
Fuel/Oil Mixture

1. Use a quality 2 cycle oil and mix it to the OIL supplier's recommended ratio. Today I use Stihl 2 cycle oil mixed @ 50:1 in a Pioneer that I purchased new in 1980. There are no gouges or scratches on the piston or cylinder and I have no carbon build up on the piston top. The manual (on stone tablets) recommends 24:1. Over the years the mixture has leaned from 24:1 (Saw Recommendation) to 28:1 (Lawn boy mower recommendation) to 32:1 (Oil provider 2gal premium/8oz chainsaw 2-cycle engine oil - used for many years) and finally the last 5 (±) years 50:1 (1gal premium/2.6oz Stihl 2-cycle engine oil)
2. Any fuel containing ethanol is not good with chainsaws. Mix what you expect to use within a few weeks. Anything over 1.5 months old use up in a 4 cycle engine. HTH

Lou

I believe the reservoir you are talking about is for the bar chain oil. You can get it most anywhere. As for mixing the gas and oil mixture, you will need 2 cycle oil. It is available most everywhere also. Most modern chain saws use a 50:1 mixing ratio which means 2 1/2 ounces of oil to 1 gallon of gas. Hope this helps.

Oil to gas mixture is more a function of the oil than the saw. If you use high quality oil like Echo brand, (or Stihl or Husqvarna) you'll be fine at 50:1. If the saw is older than 15 or so years you'd be a little safer running 32:1. It'll just smoke a little more at 32:1. I wouldn't worry about it too much.