Now that's interesting! Always something one can learn. Starter fluid is good to have on hand anyway.

Let me add a follow up: I found the article I had read about a motorcycle tech writer who suffered severe injury from welding on a piece of aluminum he had cleaned with brake cleaner. He nearly died. Here is the article:
Techs by Steve "Brewdude" Garn: Gas Poisoning

Thanks to PeteKz! +1
Good to know, and I admit I wasn't aware of it. I guess all of the brake cleaner you can buy here in europe are chloride and acetone free due to heavy environment laws. So most people here are not aware on that any more. Don't know if US/CAN or the rest of the world is so restrictive too?

Phosgen as a gas is formed by burning chloride hydrocarbons and is a serious neural poison. Due to its poisoning effect, phosgene was also used as a warfare agent in the First World War...

Before using brake cleaner have a look on to the ingredients list of your brake cleaner that it is chloride and acetone free!
I suppose that also in the US most brake cleaners are also free of chlorides and acetones as well free from aromates in the meantime.
Generally - make sure that you're starting the engine in an open area (not closed garages) only! As always.
Cleaning workpieces with brake cleaner before welding, as described in the article, is a completely different matter!

Conclusion: The best way is to use a start spray instead of brake cleaner, no question!

Thomas

Status Update…………
 

Charles,

It has been exactly a year (March 23, 2023) since you were informed that you had the wrong WUR. The WUR-089 is not the correct component for your ‘81SC with lambda/OXS. Unless you install a good working WUR-090, your problem will not go away. Good luck.

Tony