Chainsaw issue

Chain jamming or chain brake fault? I presume you?re using the correct oil/fuel mix and the engine isn?t tightening up? How about the chain oiler? Is it consuming oil at the expected rate?

Tim

Sounds similar to a problem I had with a petrol mower. Turned out to be dirt in the fuel line and a partially blocked fuel filter.

Check fuel tank/filter for debris/chippings blocking outlet pipe.

Any idea how to get to that ?

I just took plug out again .. nice biscuit colour so all seems well there. Used compressed air to blow through carburettor breather pipe back to tank - all clear.

Carburettor is a Zama W26 .... not sure if it has a diaphragm or not, if so I suppose that could be suspect.

With many chainsaws, the "carburetor" is in fact a fuel pump worked off crankcase vacuum. So it will work in all positions.

Possibly although my money would be on Chris and Harry's suggestions of a fuel blockage.

rick <rick_hughes@_remove_btconnect.com> posted

Very common problem with small two-stroke engines. Usually turns out to be gunk in one of the carburettor passages or apertures.

On 12/01/2019 14:04, rick wrote:> I have a McCulloch 360T > Starts fine .. either hot or cold ... which in itself is a good > indicator that many things are Ok with the saw. >

Always a good idea to have a new plug available, I have one here that runs for 20 seconds then stops, it had me fooled for a long time as I thought the fault was in the coil.

Apart from vacuum forming in the tank there are a couple of things:

2 blocked filter in gallery between pump and needle valve in carb, this is a metal mesh. Occasionally this can also trap a blob of water which leads to erratic behaviour.

AJH

That would be the symptom if the fuel tank air vent was blocked.

just had the same thing on a leaf blower new diaphragm fixed it

Inclined to agree. ;-)

Tim

Need a special tool to remove H & L adjustment screws (mixture) as they are splined - just ordered one ..... I'll remove and see if any gunk in them.

I agree - it sounds as if it is running out of fuel, despite fuel in tank. Check the fuel pickup pipe in the tank - if should be flexible and have a weight in the end, so gravity keeps it in the fuel.

Fuel issue