Atlas fuel lines

Does anyone have a pic of the correct routing for the fuel line on 1966-67? monobloc equiped bikes? The monoblocs are not chopped but full left/right bowl version.

Re: 1966 Atlas fuel lines

Joining this thread
From my research the 66 Atlas is the only year for 389/689 combo. I bought one as a non runner. I would not vouch that what I have with my 66 was factory correct... or that I can now even find the fuel harness any more. The drive train is currently out of the rolling chassis.

air filter:
In addition the 66 only has the matching air filter with two dimples to accommodate the carbs fuel inlet. Chopped monobloc air filters have only one dimple. I have both of these.
http://atlanticgreen.com/images/389689airfil.jpg
I'm researching to see if the concentric atlas' 67partial/68 air filters have no dimples, as they would not be needed. My 68 Dunstall atlas came with no filter...So I don't have one.

Hi Dave
Always wondered what those dimples are for?
I will be fitting an air filter on my 650SS when I get round to it?

I would assume the 66 Atlas would have the same fuel tank with one tap and the lines would be the similar to the earlier bikes with the chopped bowl?
Bit of a quick search I have come up with no information?
Mark

Burgs said:

I would assume the 66 Atlas would have the same fuel tank with one tap and the lines would be the similar to the earlier bikes with the chopped bowl?

Mark

Click to expand...

Wrong
1966=389/689 are complete R&L carbs with each their own fuel line hook up.There must be a T out of the single tank feed to split for 2 carbs

NON66=389/chopped389 combo... the LH carb/float bowl feeds the bowl of the RH carb thru a tube/hose. RH carb has no tank connection.

650SS=376-275/376/276(chopped) only has one tank outlet and single carb fuel inlet like non 66 atlas. RH carb has no tank connection.

I found it interesting there are almost 250 389 P/N applications and only about 10 689 P/N applications... all are 1966.

Thanks Dave and let me know if you find any old pictures or the harness itself. I have a matched set 389/689 correct for a 66 Atlas but dated 2/67. I haven't figured out how I want to run the fuel line as of yet. I can split from a t-piece or off a double nipple banjo from the left carb. Not sure which set-up would be less starving of fuel. Thoughts?????

I'm running velocity stacks.

Scott

kernel65 said:

. I haven't figured out how I want to run the fuel line as of yet. I can split from a t-piece or off a double nipple banjo from the left carb. Not sure which set-up would be less starving of fuel. Thoughts?????

I'm running velocity stacks.

Scott

Click to expand...

Scott:

If you study my data on fuel flow thru a petrol tap, and thru needle and seat, you will see that the factor which throttles the flow most is the needle and seat. Thus if you tee off either way, you gain fuel flow potential.

I would think a double banjo would be the "cleaner" method, as well as the way it was done by Norton.

https://www.accessnorton.com/threads/flow-measurements-on-ewarts-fuel-tap.21225/

Slick