OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters McCulloch Trimmers & Brushcutters Question regarding Fuel Lines

Hi guys,

So I'm working on some line trimmer (whipper snippers) and many of them seem to have deteriorated fuel lines (to be expected) .. question is, how do I determine which fuel line to use, as they seem to come in different sizes/thicknesses? Does the manufacturer generally include that info in the service manuals (will have to google manuals) ?

Q #2: I'm getting good and pulling things apart.. but remembering where things go and putting it back together Im still learning (lol) .. with Carburetors, there's 2x lines that run from it, one is (I think) suction that goes to the primer bulb(?) and has the fuel filter attached(?).. what does the other do?
When I push the bulb, it seems to push air out of it.. I'd think it would push the fuel into the cylinder.. but the line runs back into the tank...

Q#2 solved: It's a return line for excess fuel.

[EDIT] new Question .. does the size/type of fuel filter matter ?

But if anyone knnows about what correct spec fuel line to use, please let me know

Thanks guys.. sorry for the text, hope I made sense.

Regards,

your fuel line in all the whipper snippers i have is just a tight forced fit through the hole in the tank. so if you measure the hole size in the tank make sure you get a hose thats just slightly larger so it squeezes in tight for no leakage. my 2 ryobis use 5mm and i also have squeezed in 5.5mm.the hole in the plastic tank is about 4.8mm (on mine)

Here in the States they don't usually have the line sizes in the repair manual and a lot time they don't spec the sizes in the part lists as they want you to buy their lines.

Fuel lines are specified in two dimensions, the inner and outer. So measure the size of the pipe on the carby for inside diameter and the size of the hole in the tank for outside diameter. There are dozens of different sizes available. Take a piece of your old one to a mower shop and they will probably have it in stock along with a matching filter pick up.

Thanks guys :), Ill measure up the holes to confirm sizing ... problem I've found though with measuring the pipe, they seem enlarged, distorted or shrunk so haven't been able to get a proper reading

That is something that I have got custom to here as I deal the various effects of Ethanol and other fuel additives. The line shrinkage is something that has to taken into account with replacing lines especially on those tank through holes. Many of the lines that I replace that has already been replaced are usually because the installer went for only a slightly fiction fit.

As Aussietrev mention you do need taken account both the ID and OD sizes and many aftermarket lines will fit one way but not the other on some setups. I especially had problems with Homelite trimmers here until I found some aftermarket Echo rubber fuel lines that had the ID and OD that I was needing.

Also when installing new lines it is better to pull the lines through than trying push them. This way you take advantage of fact that these lines OD when stretched shrink temporarily allowing them to slipped through easier. When pushing the opposite is happening which makes them even harder to get through.

To me there is no hard and fast rule here as you need some experience with the conditions on your end which lines works best on which products. It has took me several years of trying different lines to settle on which works best for which products and then the manufactures will change things just makes things different.

Patience is key to working on these.