Fuel lines & routing

[Owestfall]

I am restoring an 80 mns and am in the process of hooking up the fuel lines from the petcocks to the octy and want to make sure I get them correct as they were removed I have looked a posts for some help but would like some in put as to where the lines run. two lines which come from the octy have t's which I think goes to the carbs and also hooks to one side of the petcock. one line feeds two carbs,does other line from the petcocks run into the other open inlets on the octy? all four lines have in line filters does this sound correct does any one have any pictures of the setup also in which postion should the petcocks be in when I go to start this up, carbs were taken apart and cleaned and reassembled
thanks

[Stepka]

http://www.xs11.com/xs11-info/tech-t...g-diagram.html

Did that help?

[mjpxs11sh]

welcome to the site! i have a link for ur bike @ bikebandit.com. 1980 MNS octy routing. any further questions just post. everyone is here to share info!
Ride On
Michael
http://www.bikebandit.com/houseofmot...8242#sch222001

[vintagemcyclegu]

Diaphram mounting

I am doing the same right now and I can not see where to mount the diaphram assy. Can anyone tell me. Thanks.

[crazy steve]

I am doing the same right now and I can not see where to mount the diaphram assy. Can anyone tell me. Thanks.

There should be a bracket between carbs 1 & 2 mounted via the slide diapham screws that the fuel diapham mounts to. This will be on the 'front' side of the carbs.

[jetmechmarty]

IIRC, it mounts to the cap of the #1 carb with the vacuum tap pointed to the left side of the bike. I'd go have a look, but I'm a long way from my bike.

Marty (in Tampa)

[Owestfall]

fuel lines

I posted a question about routing my new fuel lines on my 80 mns got a couple of answers with diagrams and I had done it right according to the diagrams but this may sound like a stupid question. it says in the instructions that came from a service manuel that if you put the petcocks in the on or res postion engine off, gas should not flow from the fuel pipes (A) which it doesnt, that was test one, now test two says that if you remove the vacuum tube and pull a vacuum fuel should flow. How can it flow if it doesnt flow before you pull off the vacuum hose, its off at the tank so what good does it do to remove vacuum hose and draw a vacuum maybe I'am not following something here and what postion should petcocks be anyway when you go to start and run the bike

thanks

[jetmechmarty]

There is a vacuum hose between the shutoff valve (octy) and the #1 carb holder. You have a fuel line between the "ON" tap and the valve, correct? The cock is positioned to "ON". Fuel should flow to, but not through the shutoff valve. (the book may call it a switch) Remove the vacuum line from the carb boot and apply vacuum. (suck on it) Fuel should flow through the valve with vacuum supplied. With vacuum removed, the flow should stop.

[OregonRider]

The Octy works off vacuum from the carb. Vacuum from the running engine opens the octy valve alowing fuel flow. When the engine is off the valve closes shuting off fuel flow, at the octy only.
If the bike has not run for a while or the carbs have been drained, turn the cock to Prim. this bypasses the octy and allows fuel to flow directly from the forward cock nipple to the "T", to the carbs.
Once the bike starts turn the cock to run. Fuel will then flow from the rear cock nipple to the inside octy nipples thru the now open octy valve outside nipples to the "T" and the carbs.

This is why many of us just remove the octy, plug the cock primes and the vacuum on the carb and run the fuel lines directly to the carb. RT cock to left carb bank, LT cock to right carb bank using inline fuel filters. Just remember to shut off your fuel cocks!