Source of Potassium in air cooled engine UOA?

[shanneba]

I have a Harley Sportster 1200 air cooled engine. My three UOAs have all had 11-22 ppm of potassium, I don't know where it could come from as there is no coolant.
I've used three oils, HD 360, HD SYN3 and Red Line MC all in 20w-50.

I do run Red Line SI1 fuel injector cleaner (1 - 2 oz per 4.5 gallon fill about once a month) and mostly Shell VP 93 gasoline.

Any Ideas?

 

[MolaKule]

Potassium is an additive.

It could be a potassium tri-borate AW/EP additive and or part of the detergent/dispersant agents.

What does the VOA of this oil show?

 

[shanneba]

A VOA of the Harley HD360 showed 3 ppm Potassium. Three others of SYN3 showed no Potassium.
I didn't do a VOA of the Red Line MC 20w-50.

 

[MolaKule]

Some fuel additives also may contain a small amount of a potassium compound as an anti-corrosion agent.

 

[OneEyeJack]

Some ester based oils like Red Line use a stable dispersion of nanoparticulate potassium borate that acts as a friction modifier and a mild corrosion inhibitor.

If this additive attaches itself to metal does it mean that a UOA is not useful in establishing the potassium level in the engine and may not relate to levels in a VOA?

 

[ExMachina]

A little gets in to the oil via the air filter past the rings. Airborne dirt dust.

 

[MolaKule]

Originally Posted By: ExMachina
A little gets in to the oil via the air filter past the rings. Airborne dirt dust.


No, that is silicon. Most dirt and dust is composed of silicates.

 

[weasley]

Do you live on the coast? Sea water contains K.