The gas cap on my 2 cycle weed eater1700 has a liitle red piece in middle that has been pushed through

Found this previously posted:

Cut two separate pieces of string, about 7 ft. each.

Stick the end of the line in the hole on the inside of spool.

Wind clockwise onto spool, putting the line that is closest to the ground on first.

Once you have winded this piece on, lock the last 4 inches of line through the slits on spool.

Repeat process for second piece of line, locking the last 4 inches in slot opposite the other locked in piece.

Put the spool on the trimmer, feeding the end of lines through either hole on trimmer.

Before you push the spool all the way on, pull the strings out of the locked position. Put cap on and GO CRAZY!

The ratio is 40:1 Just add 3.2 ounces of 2 cycle oil to one gallon of fuel. Be sure to cap off the tank and shake to distribute the oil throughout the fuel before adding to weed eater.

it is a tank vent. it allows air into the tank as it empties. replace the duck valve or get a new cap

If you need further help, I’m available over the phone at https://www.6ya.com/expert/kelly_69a0cf1b13789df1

be sure fuel filter is on the primary fuel line in the tank.check primer bulb and fuel lines.also check fuel tank cap.vented cap may be stopped up

I found the manual for this model weed eater, according to the manual the mixture...
and I quote "This engine is certified to operate on unleaded gasoline. Before operation, gasoline
must be mixed with a good quality synthetic 2-cycle air cooled engine oil designed to be
mixed at a Ratio of 40:1 ...." and I quote once more from the manual "Helpful Tip. To obtain
correct oil mix ration, pour 3.2 ounces of 2 cycle synthetic oil into one gallon of fresh gas."

Hope that helps,
If you like I can send the manual via email if you need it.

:) happy weed thrashing

Don't know that exact trimmer, but I always run 40:1 in all my trimmers, chainsaws, etc. That is 3.2 oz. of 2 cycle oil to one gallon of gasoline. I rebuild these machines daily and run that mix in everyting, except when it's actually specified on the machine.

2 cycle engine takes a 40:1 gas mixture.
Good Day.

FUELING ENGINE
WARNING: Remove fuel cap slowly
when refueling.
HELPFUL TIP
To obtain the correct oilmix
ratio, pour 3.2 ounces of
2--cycle synthetic oil into
one gallon of fresh gas.
This engine is certified to operate on unleaded
gasoline. Before operation, gasoline must be
mixed with a good quality synthetic 2-cycle
air-cooled engine oil designed to be mixed at a
ratio of 40:1. Poulan/Weed Eater brand
synthetic oil is recommended.Mix gasoline and
oil at a ratio of 40:1. A 40:1 ratio is obtained by
mixing 3.2 ounces (95ml) of oil with 1 gallon (4
liters) of unleaded gasoline. DO NOT USE
automotive oil or marine oil.

Replace the cap. they are not expensive.