On gmc line trimmer how do I know if the fuel filter needs cleaning ? or replacement ?

hello sir,routing fuel line for craftsman,homelite,ryobi,hedge and line trimmers,fuel tank under engine, looking at machine from rear, shall fuel line on left with filter attached goes to bottom port of carb, fuel line from right side coming out of tank with inside tip attached goes to bottom port of primmer bulb,top line on primmer bulb goes to top port of carb, fuel tank under engine,fuel line routing,looking at machine from left side, left fuel line coming out of tank(drain back only) goes to right side small port of primmer bulb, left side larger fuel line from primmer bulb to top port of carb, fuel line coming out of tank (larger line) on the right side with filter attached goes to bottom port of carb, when replacing fuel line it is very important to use the same ID and OD line the homelite takes a special line that is black in color and a bigger size,the bigger line is ID .08-OD140 small line ID3/32 X 3/16.when the lines dissolve small pieces will get in the carb clogging small passages and screen,it is advisable that you clean out carb,and use a new filter.hope this helps,any comments welcome,thank you. if the filter has broken off of the line half way that is where you will run out of fuel, ``

hello sir,routing fuel line for craftsman,homelite,ryobi,hedge and line trimmers,fuel tank under engine, looking at machine from rear, shall fuel line on left with filter attached goes to bottom port of carb, fuel line from right side coming out of tank with inside tip attached goes to bottom port of primmer bulb,top line on primmer bulb goes to top port of carb, fuel tank under engine,fuel line routing,looking at machine from left side, left fuel line coming out of tank(drain back only) goes to right side small port of primmer bulb, left side larger fuel line from primmer bulb to top port of carb, fuel line coming out of tank (larger line) on the right side with filter attached goes to bottom port of carb, when replacing fuel line it is very important to use the same ID and OD line the homelite takes a special line that is black in color and a bigger size,the bigger line is ID .08-OD140 small line ID3/32 X 3/16.when the lines dissolve small pieces will get in the carb clogging small passages and screen,it is advisable that you clean out carb,and use a new filter.hope this helps,any comments welcome,thank you. if the filter has broken off of the line half way that is where you will run out of fuel, ``

hello sir,routing fuel line for craftsman,homelite,ryobi,hedge and line trimmers,fuel tank under engine, looking at machine from rear, shall fuel line on left with filter attached goes to bottom port of carb, fuel line from right side coming out of tank with inside tip attached goes to bottom port of primmer bulb,top line on primmer bulb goes to top port of carb, fuel tank under engine,fuel line routing,looking at machine from left side, left fuel line coming out of tank(drain back only) goes to right side small port of primmer bulb, left side larger fuel line from primmer bulb to top port of carb, fuel line coming out of tank (larger line) on the right side with filter attached goes to bottom port of carb, when replacing fuel line it is very important to use the same ID and OD line the homelite takes a special line that is black in color and a bigger size,the bigger line is ID .08-OD140 small line ID3/32 X 3/16.when the lines dissolve small pieces will get in the carb clogging small passages and screen,it is advisable that you clean out carb,and use a new filter.hope this helps,any comments welcome,thank you. if the filter has broken off of the line half way that is where you will run out of fuel, hh

hello sir,routing fuel line for craftsman,homelite,ryobi,hedge and line trimmers,fuel tank under engine, looking at machine from rear, shall fuel line on left with filter attached goes to bottom port of carb, fuel line from right side coming out of tank with inside tip attached goes to bottom port of primmer bulb,top line on primmer bulb goes to top port of carb, fuel tank under engine,fuel line routing,looking at machine from left side, left fuel line coming out of tank(drain back only) goes to right side small port of primmer bulb, left side larger fuel line from primmer bulb to top port of carb, fuel line coming out of tank (larger line) on the right side with filter attached goes to bottom port of carb, when replacing fuel line it is very important to use the same ID and OD line the homelite takes a special line that is black in color and a bigger size,the bigger line is ID .08-OD140 small line ID3/32 X 3/16.when the lines dissolve small pieces will get in the carb clogging small passages and screen,it is advisable that you clean out carb,and use a new filter.hope this helps,any comments welcome,thank you. if the filter has broken off of the line half way that is where you will run out of fuel, hh

Hi David, bring the high speed screw out until it accepts throttle, regards Phil.

Let's start with the easy stuff first. Remove and clean the spark plug. Look into the tank and fish out the fuel filter. It should be stuck in the end of the fuel line in the tank. I usually use a short piece of coathanger with a small hook bent into the end of it. Clean or replace the fuel filter. The next thing is to clean the small screen at the exhaust. Remove any carbon build-up there that you can. Sure hope this helped and best wishes.

The longer, and sometimes smaller in diameter fuel line, goes from the carburetor to the bottom of the tank. This line, which has the filter attached to the end, should rest comfortably on the bottom of the tank.
The other fuel line goes from the primer bulb to just inside the tank, (about an inch, with that very small piece of plastic attached to it. This piece of plastic keeps this line from pulling out of the gas tank. this line serves as an overflow from carb.

Jim

it sounds like the filter on the fule line is cloged try to remove the filter and then try to prime the trimmer. it it does you need to replace the filter. just about any filter that will fit will do.

Just break off plastic caps to access the low and high speed jets. They are there because of government regulations to prevent users from adjusting carb in the field. They serve no other purpose.

Supply line with filter is suppose to be one piece from the tank to the carb. If it has a barb coupling in the middle then someone must have tried to patch the line at some point. You can get a replacement line and filter as part #682039 by searching online or ebay. Or you can just order line and reuse filter if it is not plugged. Required line is 3/32 ID x 3/16" OD. Both dimensions are critical. To replace line you have to take retaining ring off the bottom of the fitting on the tank (use a knife or scraper to pry it off the bulge in the hose) and push the filter fitting into the tank. Remove from tank through the fill opening. Remove piece of hose that is still on the barb. Push on new section of hose all the way to the top of the barb and right up to the filter. Put other end of hose through tank fill opening and through hole in bottom of tank. Use a piece of wire or a straightened paper clip to guide it to the hole. Pull hose through until the bulge gets to the opening. Pull hose firmly, but carefully so the hose stretches enough to allow the bulge to go into the hole in the bottom of the tank. Stop when the bottom edge of the filter is about 1/8" from the inside bottom of the tank. You should see enough of the barb end sticking through the tank for the retaining ring to be replaced on the outside bottom of the tank. If not enough exposed, pull hose through a little more. Thread line to carb input and insert. Inlet fitting will have barbs or a bulge on it. The return fitting on the carb is a straight tube with no barbs. The line from that fitting (3/32 x 3/16 also, as all lines are) goes to the top (suction side) of the primer. The other side of the primer has a line that returns to the other opening in the tank.

The return to the tank must have a fitting similar to the filter fitting, but without the filter. It is a barbed fitting with a flange ring on the end that is inside the tank and it has the retaining ring on the outside just line the supply side line. It sounds like you are missing that fitting, because you are describing the hose just being pushed up into the tank. Without that barbed fitting in place the tank will leak gas. The bulge in the line caused by the line fitting over the barbs is what seals the opening. You can order a return line kit 147290 from MTD parts that will have the line, the barb fitting and the retainer ring. In a pinch you could get use an 1/8" hose barb from a hardware store and just arefully pull it through the opening so that the bulge in the barb/hose combination is sealing the tank both inside and out. You can get by without the retaining ring. Otherwise look for a junk IDC/Ryan/Ryobi trimmer to scavange parts off of.

Sounds like you may still have a carb problem to deal with. Did you remove the needle valve to make sure it is not stuck or inlet plugged or restricted? Fuel screen clean? May need a diaphragm and gasket set. Good luck.