OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Trimmers and Brushcutters Two Stroke Trimmers & Brushcutters Oleo-mac Brushcutter?

Hi all just wondering if anyone can help me out with info on a Oleo-mac Brushcutter. It was given to me and all that is written on it is Oleo-mac King 40a electronic brushcutter. It's not working at the moment, it will fire if I put some fuel down the cylinder but wont start. Would like to restore it to working condition. My question is about parts ie, carby kits or another carby. Is this model the same as any other Oleo-mac machines? How many cc's is it? Any help would be appreciated. Thanks.

Is that a straight-shaft brushcutter (that is, with bevel gears at the cutting head end, not a curved shaft)? I can't find any reference on the internet to that model, but generally Oleo-Mac has one series of two-digit model numbers that are about 2 numbers higher than the engine size, so yours may be about 38 cc - a reasonable size for a straight-shaft, fairly serious brushcutter. Oleo-Mac is an Italian company but appears to have its brushcutters made in India.

It appears that your engine is not receiving fuel, but I would not begin by rebuilding the carburetor. You need to check the fuel pickup in the tank (filter-head not blocked, hose not split), verify that air is entering the tank (it will either have a vent-cap with a one way valve, or an air pipe going into the tank, and both of them give trouble), check that the carburetor filter (fine mesh in the chamber above the fuel pump diaphragm) is clean, and ensure that the crankcase pulse line to the fuel pump chamber (it may be an external rubber hose, or a drilled hole into the crankcase from the carburetor) is clear.

Are you following the correct procedure with the choke? It is similar to a chainsaw: you close the choke completely, set the throttle to the start position (on some models you hold the throttle partly open by hand), turn on the ignition, and pull the starter until the engine burps (runs then stops). You then set the choke to the halfway position, and pull the starter a few more times until it starts and runs.

If you have a clean, working fuel system and the engine won't even fire a shot when you use the correct starting process, it is time to start thinking about a carburetor overhaul. However I think many more carburetors are ruined by enthusiastic owners taking them apart, than ever deteriorate in service. Try everything else first.

Yes straight shaft. I will give everything that you said a go and I will let you know how I go. Thanks for that!

There is one other thing you might check. In case the previous owner had been experimenting with the mixture, look at the carburetor. There will usually be 2 mixture screws (brass screws with a spring under the slotted head, side by side, going into the carburetor body - not the idle speed screw, which holds the throttle butterfly slightly open). With a screwdriver, turn each of them clockwise gently, carefully noting how far they turn before they stop. Don't use force, they are delicate. You will probably find they both rotate about one and a quarter turns. If so, put them back exactly where they were. If they are open less than one and a quarter turns (i.e. leaner mixture than normal), that may be a problem. If they are open more than that (i.e. richer) don't worry for now, just put them back where they were.

Yep tried all of the above. Checked all lines, new fuel, has spark, the only way I can get it to idle for about 5-8 seconds is to take out the plug put a bit of fuel down the shoot and BANGO away she go's. Then DIE! won't even fire after that. Thinking carbie?

If you followed all of those steps, it sounds like fuel pump or carburetor (and the fuel pump is part of the carburetor anyway). You may find the same carburetor on a scrap brushcutter, or you could put a kit in the one you have. If you are going to overhaul the carburetor you will need a manual (or access to a local expert). Can you find the make and model of the carburetor? There are three common brands, but quite a few models, and lots of Asian knock-offs of all of them. It is actually a chainsaw carburetor. You could substitute a different carburetor from about the same sized engine, but then you will have issues connecting the controls, and perhaps even in mounting the carburetor on the engine.

It's a Walbro without a primer.

Sounds like a WA or one of the similar models. You can download the manual here:
http://wem.walbro.com/distributors/servicemanuals/WAseries.pdf

If that doesn't look like your carburetor, see if you can find the right one on this page:
http://wem.walbro.com/distributors/servicemanuals/

Yippy found it. It's a WT series.

Sounds like you're in good shape for the next few steps. It is quite a good manual.

Thankyou Grumpy for all your help. Much appreciated.

You are welcome Big Daddy, I'll close the thread.