White emulsion on choke butterfly?

[TimberCutterDartmoor]

Saw running a but funny.

 

Spark plug perfect colour.

 

Found white emulsion on choke flap. Spray off, comes back almost instantly with air cleaner off (so that you can watch it).

 

Fresh fuel this week.

 

???

 

Thank you.

[C.J]

Humidity

[openspaceman]

Humidity

 

Yes, my guess would be petroil evaporating off the carburettor innards cooling it such that the air going in is below its dew point, hence it condenses out on the cold butterfly.

 

The reason it's an emulsion is that the petrol evaporating has left a film of oil which the water droplets settle on.

Edited December 15, 2016 by openspaceman

[peatff]

It's mayonnaise, are you putting olive oil in the fuel mix ?

[TimberCutterDartmoor]

Well after wasting £40 at a Garden Machinery shop who say they fitted a new plug, 1 of 2 carb diaphragms and a few other checks the saw is now dead...

 

They were frankly clueless.

 

But then so am I. Just dies after startup, hard to start, basically shelved as non production isn't costed in.

[peatff]

What model saw is it ?

[TimberCutterDartmoor]

CS600; can't believe it would be carb icing at 12 degrees

[TimberCutterDartmoor]

Yes, my guess would be petroil evaporating off the carburettor innards cooling it such that the air going in is below its dew point, hence it condenses out on the cold butterfly.

 

The reason it's an emulsion is that the petrol evaporating has left a film of oil which the water droplets settle on.

 

Only seemed to be the choke butterfly, not the throttle one...

[TimberCutterDartmoor]

pic ..

[Sawchip]

Saw running a but funny.

 

Spark plug perfect colour.

 

Found white emulsion on choke flap. Spray off, comes back almost instantly with air cleaner off (so that you can watch it).

 

Fresh fuel this week.

 

???

 

Thank you.

New fuel or not.. it sounds from your description that moisture is involved some where. "Running a bit Funny"..."starts poorly"...points to some moisture in the mix . I would be looking to eliminate the fuel that is in /was in the saw and pop some fresh mix in the saw. Establish a datum by getting different fuel that you see working in another saw. Its not imposable to get wet from the air causing a emulsion ...but to have a long term affect ...more likely to having a fuel issue of some sort I feel. Cant be much though or hydraulic lock would be posable. My 2 penny worth anyhow .

Edit: Stihl saw? Echo?...they spit some fuel back towards the air filter so you could get the gunge showing there .

Edited December 15, 2016 by Sawchip