fuel filters

[jjz28]

What is the best way to run filters and route the fuel line? My petcocks are messed up and I have to run reserve all the time cause the on postion fuel dont flow, just reserve. Any way i am getting black specs of stuff under my float valve seats and need to run filters but cant get them run without kinking. Also, what is the best fuel line that wont kink. That lawn mower fuel line sucks, it gets really soft and collapses.

[DGXSER]

First question, do you still run the Octy valve? If yes, it gets harder to do, if not then it can be really easy.

There is many opinions on how to run the lines, for me, I like to keep it simple, so I come straight out the petcock, down between 1-2 air box boots, put a small MC fuel filter in line, the pyrimidal type with the gold color stone looking filter media, fits well between the boots, then directly to the carb tee for 1-2. Repeat on the opposite side.

The fuel line for my set up dips down and almost touches the engine, my fuel tees point downward, makes a J shape.

Like I say, lots of folks do it differently, that is my method that works well for me. As to type of line, got to a local shop, ask for MC fuel line, they should have the black stuff that is harder than the lawn mower stuff. Personally, I used the B&S lawn mower fuel line on my previous SH and worked really well in the same configuration.

[CatatonicBug]

You can get 90º fuel filters to put in the lines as they loop under the air box. Point the Carb fuel inlets downward. Run each line from the carb fuel inlets, about 1.5", then add the 90º filter. Continue both lines up between the 2 and 3 air intakes, along with the crank case breather hose. The lines then loop back toward the octy, with the "T" splitting off to connect to the front port on the petcock.

[mikubuilder]

'79 doesn't have octy...it started in '80s... like Bug said, run longer loops down under and back or cross them over(seen it both ways)

[mikubuilder]

speaking of lawn mower line that double wall crap I bought is not even good for my lawn mower...(collapses, cracks, and that's were those black specks come from--I think)

[CatatonicBug]

'79 doesn't have octy...it started in '80s...

Yes it does... All the specials had the octy.

Oh, and as a suggestion for fuel line, get Tygon. I got it at O'Reilly Auto Parts.

[DGXSER]

this is one of those YMMV issues, almost like oil and tires. Several folks use the automotive double wall stuff with no issues at all.

Me, I spent hours and hours removing and cleaning and reinstalling carbs till I was ready to roll my bike down a hill and burn it up, trying to stop leaking floats....until I got rid of that double wall fuel line. Never another issue with that after I switched to the B&S lawn mower fuel line. Its the soft inner rubber on that double wall stuff that flakes off going over the Ts in the system, or least it did for me.

And yes, all of the Special models had the Octy. I have a set of the 79SF carbs right now, you can tell because the plate that over the diaphram covers that links the bodies together on top has a tab, and threaded hole where the Octy would bolt up molded into it.

[Titans]

I dropped the fuel line in between 1&2 and 3&4 like stock, but then I installed in-line fuel filters and looped them to the carbs accross the way. For example, the fuel line which drops in between carbs 1&2 fuels carbs 2&3 (and vica verca). the in-line filters sit vertically pretty much in between the carb/airbox boots.

[jetmechmarty]

Whether you have the "octy" or not, I put a small Visu-filter just above the fuel tees between carb 1&2, and another between 3&4.


I like tygon fuel line. It's very easy to work with and it stays flexible.
MP Premium Fuel Line, Black 1/4 ID X 3'


To give me more room, I routed my fuel lines from the left pectcock to the right carbs, and the right petcock to the left carb. I have a Special and I have retained the vacuum shutoff valve.

[Titans]

Whether you have the "octy" or not, I put a small Visu-filter just above the fuel tees between carb 1&2, and another between 3&4.


I like tygon fuel line. It's very easy to work with and it stays flexible.
MP Premium Fuel Line, Black 1/4 ID X 3'


To give me more room, I routed my fuel lines from the left pectcock to the right carbs, and the right petcock to the left carb. I have a Special and I have retained the vacuum shutoff valve.

I believe our lines are 3/16ths though.

[natemoen]

I believe our lines are 3/16ths though.

Nope, they are 1/4". Some get by with 3/16" and then don't use clamps.

[skids]

Whether you have the "octy" or not, I put a small Visu-filter just above the fuel tees between carb 1&2, and another between 3&4.

I tried using that type filter and they warped. I go with the metal inline ones made by Fram. They are a bit larger but if you cross over from the petcocks to the carb tees, there is plenty of room and you can still lift the tank for synching...

[jjz28]

I ditched the octy in the beginning. The lawn mower line worked but kinked really bad.

[mikubuilder]

my bad on octy...I guess I should just shut up and listen to others who've been around a lil' longer

[bikerphil]

One thing about running inline filters on a 79 Special is the 79 has those extra carb vent hoses running up to the airbox that makes it even more challenging to run the fuel lines from the petcocks. Not as much a problem with the 80-81's. My 2¢.