Topic: Brass fittings - yes or no?

[Ellz10]

I seem to be finding conflicting opinions from people on the matter of brass fittings for fuel lines, fuel systems. One theory I read stated "Brass contains zinc, and you would never use that in a fuel system as it reacts with the fuel and can block precision injectors, filters etc".

However the Mikuni RS34s I bought came with a T fitting that is brass (or so I believe) so it begs the question - is brass really a no-go in the fuel systems on these, or any, bikes?

Main reasoning behind this is my petcock is 1/4 and my fuel line is 5/16 so I was about to snag a small 1/4 to 5/16 reducer fitting.

Any thoughts on the brass theory/idea?

[bryanj]

So why are all the jets, etc brass and loads of old british carbs brass, i think the brass corrosion with fuel is a myth

[C317414]

I've never had a problem with brass fittings and fuel in motorcycles or cars.  Here's an excerpt from a SAE study with E10 and E20 gasoline.  Non-ethanol gasoline will be even less of an issue:

https://www.sae.org/publications/technical-papers/content/2013-01-2880/

[C317414]

BTW, I think the misinformation regarding brass and gasoline comes from the boating industry.  Brass is not compatible with salt water and should not be used in any assembly exposed to it.  Salt water will corrode the zinc in the brass alloy and leave behind weak, porous copper.   Bronze is the proper alloy to use in areas exposed to saltwater. 

[Ellz10]

So why are all the jets, etc brass and loads of old british carbs brass, i think the brass corrosion with fuel is a myth

I thought about that as well and it just didn't make sense.

I've never had a problem with brass fittings and fuel in motorcycles or cars.  Here's an excerpt from a SAE study with E10 and E20 gasoline.  Non-ethanol gasoline will be even less of an issue:

https://www.sae.org/publications/technical-papers/content/2013-01-2880/

Upon reading they note that the brass samples showed substantial tarnishing after testing, however all the metals, including the tarnished brass, were found to show no significant corrosion.

So at worst all I would need to do if I deemed it necessary would be to replace the fittings after so long when they start to tarnish.

I'll be running either 104 ot 107 so I would imagine that might speed up the process; I'll have to wait and see

Thanks for that article!

[bryanj]

Tarnish will not be a problem unless it is so severe it increases the size of the metal, like rust on steel.

[Tracksnblades1]

Elltz10,

Those RS’s come in 36,38, and 40…
I’m thinking the 38 and 40 come ready or as an option to run straight methanol.
I’m also thinking the brass isn’t the issue with new methanol that hasn’t absorbed moisture (water).

However any nitromethane/ methanol mixtures will find all the brass in your fuel system…😩

[Ellz10]

Elltz10,

Those RS’s come in 36,38, and 40…
I’m thinking the 38 and 40 come ready or as an option to run straight methanol.
I’m also thinking the brass isn’t the issue with new methanol that hasn’t absorbed moisture (water).

However any nitromethane/ methanol mixtures will find all the brass in your fuel system…😩

Oh boy, running a nitro-meth 750 would be bananas!!! I'd never wanna stop riding lol