Question about Lawn Trimmers & Edgers

1 Answer

Fuel air lock in Grass Scorpion trimmer

Primer bubble does not fill with fuel. Air lock somewhere in the line. How do I fix it?

Posted by on

  • SoreArmRay Nov 24, 2008

    I have the same problem, and suspect the fuel lines are mixed up.

    So far I got this from the web

    RYOBI Grass Scorpion

    Fuel lines
    1 - outlet from feul tank -> primer inlet(short writen IN)
    2 - free end of primer(long) -> spigot (brass) on top of carby
    3 - spigot at the buttom of carby -> fuel tank

    fuel line from tank goes to primer inlet which is shorte one (on top of it writen "in") and come out from other end of primer then connec to spigot at butom of carby ( L shape one) ?

    Farshad, you are wrong!- The line from the tank goes into the longer inlet, and the line into the carbie goes into the shorter inlet.

    RST310SS,RCT2800A to 1/1994
    Model Standard Plug Gap (mm)
    Grass Scorpion T20M-U 0.6


1 Answer

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert that got 5 achievements.

    Vice President:

    An expert whose answer got voted for 100 times.


    An expert whose answer got voted for 20 times.

  • Expert
  • 163 Answers

Check the fuek lines for hole and leaks, check the fuel filter and clean if necessary. remove the carbuerator and inspect the gasket; it should be soft and flexible, if it seems hard or brittle replace it. clean the carb with carb cleaner sray (available at any local auto parts store) and compressed air. make sure you get inside the small fuel rail holes. if that doesn't work have the carb repaired at a service center or replaced.

Posted on Nov 28, 2008

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Why my weedeater idle to high and why air bubble in the primer bulb?

Its not un common to have air in the primer bulb, Check for a possible air leak in the system. This will make the saw idle higher than normal if its sucking air from elsewhere.

May 19, 2016 | Lawn Trimmers & Edgers

2 Answers

Ryobi Grass Scorpion Petrol lines from tank to primer to carby where to where

Thanks to

The line off the top of the primer bulb goes to the top of the carburetor.
The line on the bottom of the primer bulb goes to the fitting on the center of the fuel tank and the line off the side of the fuel tank goes to the bottom of the carburetor.


Oct 28, 2008 | Ryobi 15" Electric Factory Reconditioned...

1 Answer

I have a poulanpro gas trimmer ppb335. when i pump the bulb, I can see air bubbles coming from the carb to the pump bulb but not from the tank to the carb. where is it coming from?

There could be a bad check valve in the carb or a gasket leaking or even a pin hole in the fuel line. Since its the primer bulbs job to remove air from the carb and replace it with fuel; as long as the unit runs fine I wouldn't worry about it. A leaking gasket can be fixed with a rebuild kit. Bad check valve will require replacing the carb.

Aug 22, 2014 | Poulan Pro PPB335 33cc 17-Inch Gas Line...

1 Answer

I have a 124l e-tech trimmer and the prime bubble wont fill

Sounds like you have an air leak. Either in the primer bulb is split or punctured, hole or leaking fuel line or primer bulb base, and is sucking air instead of fuel.

Aug 20, 2012 | Husqvarna 124L 28cc Gas Line Grass Lawn...

1 Answer

Craftsman weedwacker 358.791070 stopped running; found broken fuel line in tank; changed same;when pumping primer bulb,the line between tank and carb fills up but line between bulb and into return line to...

the filter on the end of the line in the tank may be clogged or the gas cap may be bad they are designed to hold pressure and help push fuel in to the carb

Feb 28, 2012 | Craftsman Lawn Trimmers & Edgers

1 Answer

I have a TB70SS trimmer. I used my trimmer on half my yard with no problem, turned it off to cut the grass with the lawnmower, then tried to turn on my weedeater again, and noticed the primer bulb would...

First, the primer/purge bulb does NOT have to fill completely to function. It's purpose is to remove old fue and AIR from the fuel system (carb) and move it back into the fuel tank. You normally will have an air pocket in the bulb. An air leak in the fuel system or loose carburetor screws or fuel lines in the wrong location can cause your problem. Check the fuel line and fuel filter for a good connection in the fuel tank. Remove the fuel pump cover on the carb and make sure the very small, round, wire mesh filter is not clogged with debris. When old fuel lines deteriorate, they crumble and if the filter is broken off, the fuel line to the carb will ingest bits and pieces of old fuel line. Check all these things and post back.Sometimes, if the bulb is on the carb, a check valve in the carb can stick. When you check the condition of the mesh filter inside the carb (opposite the side with the vent hole), then liberally spray with WD 40. Strong solvents and cleaners can SWELL up the tiny check valves in the carb, causing problems. So you see, it is hard to pinpoint exactly what happened without some removal of parts and diagnosis.

Aug 06, 2011 | Troy Bilt Tb70ss Gas Trimmer

1 Answer

Primer bubble is cracked.minimal fuel is getting to carburator. when it starts it will run a few seconds then cut off.Won't run except in full choke. Please Help

The primer bulb needs to be replaced. It is introducing air to the system and not allow fuel to flow. Replace it and check the fuel lines while you are at it.
Good Day

Oct 29, 2009 | Craftsman 25cc Gas Line Trimmer

1 Answer

Primer bulb won't prime

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.

Jun 05, 2009 | Troy Bilt Tb70ss Gas Trimmer

2 Answers

Manual for Ryobi Grass Scorpion Line Trimmer

my ryobi scorpion only has twofuel lines but two on primer can you help

Mar 13, 2009 | Ryobi Lawn Trimmers & Edgers

Not finding what you are looking for?
Lawn Trimmers & Edgers Logo

Related Topics:

698 people viewed this question

Ask a Question

Usually answered in minutes!

Top Lawn Trimmers & Edgers Experts

Jim Parker
Jim Parker

Level 3 Expert

1040 Answers

Dwain Pippen

Level 3 Expert

376 Answers

Roland W VanLue
Roland W VanLue

Level 3 Expert

375 Answers

Are you a Lawn Trimmer and Edger Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides