Petcocks, Fuel lines, Carburetors, Oh My!

[OMCC]

Hi Guys
So after cleaning the carbs yet again and finding no success I decided to revisit the gas tank to see if it really wasn't as rusted as I ad been thinking. I thought wrong, when I drained the gas tank the gas was orange with rust and a ton of rust flakes came flowing out.

So today I'll be doing electrolysis to take care of the rust. (if anyone has a prefered method I'd love to hear it I found some youtube videos I'm going to follow otherwise.)


As we move along my petcocks are in iffy shape. the Right side leaks when in the res position and pours out in the on and prime position. the left side operates normally with only a slight leak (1 drop per minute) in the on/res position. I am assuming they will need to be rebuilt. I am considering changing them to non-vac petcocks. Does anyone have any experience with this? I don't have the tools to modify the fuel tank so I am hoping to find a plug and play option.

moving on to the fuel lines:

As I mentioned before my bike didn't come with an Octy ('79 xs1100 Not a special)

Was the octy was standard on all models or just the special?

Going further I am confused as to how I should be connecting the fuel and vacuum lines and which valves need to be capped off. As well as which ones need to be connected to the airbox. When you are bypassing the OCTY

I've looked at other posts and diagrams but I'm a little overwhelmed by the options.

As of now I have two lines coming off the engine side of the middle 2 carb boots going nowhere. The other two carb boot valves are capped off. then I have the four lines 2 top 2 bottom of the carburetor itself. I have the two top facing lines going to the airbox and the two bottom lines going to the petcocks.

at petcocks I had a T splitter on each side joining the Vacuum and Fuel lines (This set up doesn't make sense to me the longer I look at it)

then I have one (what I believe is a breather line) coming off the transmission housing

Can you guys help me figure out which Diagram I should be using and what should be capped, filtered,etc?

Any advice or help would be greatly appreciated!

Thanks,
-D

[motoman]

"cleaning carbs"..........can mean ALOT of things. If you haven't removed EVERY removable piece in carbs and throughly cleaned, they are NOT clean yet.
Your bike has two fuel lines/two vacuum lines. Vacuum line gos from #2carb boot brass nipple to front of left petcock. Other vacuum line goes from #3carb boott's brass nipple to front of right side petcock.
Fuel lines(if replacing) neeed to be each long enough to criss-cross....left petcock to right fuel tee/right petcock to left fuel tee.
A larger precurved hose goes from front upper portion of airbox to breather opening top of crank case.
That's it......easy-peasy.
Your petcock issue doesn't necessarily require a "kit". Largest percentage of time, removal from tank, dissassembly, cleaning pieces and polishing face of rotating lever works fine. Clean all sealing surfaces, and re-assemble................BEFORE you go buying any re-build kits(which CAN be 'iffy' anyways).

[natemoen]

Each petcock has 2 nipple on it. The one facing forward is the vacuum line, which needs to be connected to to its respective sides intake boot nipple. The petcocks nipple facing into the middle of the bike is the fuel outlet nipple. This is the nipple that is connected to the lower nipple on the carbs.

Clean the petcocks out good and check the diaphragm for any holes. No holes, then you should be good and they should work fine after a good cleaning.

[jetmechmarty]

I've done some tank derusting. I've used electrolysis, phosphoric acid, and Metal Rescue.

First question; how bad rusty is it? If it just has a rusty spot or two and you don't want to follow with a liner then I'd highly recommend using Metal Rescue or Evapo-Rust and be done with it.

If there is a lot of rust, the best easiest way to deal with it is with a solution of phosphoric acid. You'll have to follow with a liner or it will rust again in short order. I like the Caswell epoxy liner.

[Bonz]

I used Jasco "Prep and Prime" for my 80G tank, very rusty inside. Put a half quart in the tank and filled the rest of the way to the brim with H2O. Let it sit a few hours, shook it around, let it sit another few hours, rotated the tank at different angles, etc. Nice thing is this stuff won't flash rust. Drained the tank, put a bit of gas in the tank and shook it around, drained again and put the hardware back on the tank and that was that! I got the 1 qt bottle of Prep and Prime at ACE, maybe similar stores stock it as well.

[OMCC]

Originally Posted by motoman

"cleaning carbs"..........can mean ALOT of things. If you haven't removed EVERY removable piece in carbs and throughly cleaned, they are NOT clean yet.

I can assure you I've removed every possible piece I may end up bringing it to a shop to have it cleaned ultrasonically if this doesn't work.

Originally Posted by motoman

Your bike has two fuel lines/two vacuum lines. Vacuum line gos from #2carb boot brass nipple to front of left petcock. Other vacuum line goes from #3carb boot's brass nipple to front of right side petcock.
Fuel lines(if replacing) need to be each long enough to criss-cross....left petcock to right fuel tee/right petcock to left fuel tee.
A larger precurved hose goes from front upper portion of airbox to breather opening top of crank case.
That's it......easy-peasy.

This is exactly what I needed Thanks! Since I'm having the these issues with rust and such would it make sense to have an inline fuel filter. Or is that something I should only add once I get it running steady?

Originally Posted by motoman

Your petcock issue doesn't necessarily require a "kit". Largest percentage of time, removal from tank, disassembly, cleaning pieces and polishing face of rotating lever works fine. Clean all sealing surfaces, and re-assemble................BEFORE you go buying any re-build kits(which CAN be 'iffy' anyways).

I did take them apart before I set up the electrolysis and cleaned out some junk but I'll make sure to do it again and double check for tears before I hook the tank back up. worst case scenario I could just keep them on RES since that doesn't seem to leak as much as in the on position

[OMCC]

Originally Posted by natemoen

Each petcock has 2 nipple on it. The one facing forward is the vacuum line, which needs to be connected to to its respective sides intake boot nipple. The petcocks nipple facing into the middle of the bike is the fuel outlet nipple. This is the nipple that is connected to the lower nipple on the carbs.

Clean the petcocks out good and check the diaphragm for any holes. No holes, then you should be good and they should work fine after a good cleaning.

This picked up perfectly where motoman left off Thanks!

[natemoen]

Always put a online filter in the fuel lines. The petcocks only have a screen on them (if it is still intact) to keep out the big chunks. Put a filter on each fuel line. That will keep any rust particles out or other junk in the fuel and keep the carbs clean of debris.

[OMCC]

Originally Posted by jetmechmarty

I've done some tank derusting. I've used electrolysis, phosphoric acid, and Metal Rescue.

First question; how bad rusty is it? If it just has a rusty spot or two and you don't want to follow with a liner then I'd highly recommend using Metal Rescue or Evapo-Rust and be done with it.

If there is a lot of rust, the best easiest way to deal with it is with a solution of phosphoric acid. You'll have to follow with a liner or it will rust again in short order. I like the Caswell epoxy liner.

I saw this too late I had already set up the electrolysis. To answer your question though, it's not cover in rust I can still see metal. But there is enough there that it flakes off and turn the water bring orange.

If this doesn't work I'll try the phosphoric acid method or metal rescue.

[OMCC]

Originally Posted by natemoen

Always put a online filter in the fuel lines. The petcocks only have a screen on them (if it is still intact) to keep out the big chunks. Put a filter on each fuel line. That will keep any rust particles out or other junk in the fuel and keep the carbs clean of debris.

Will do thank you!

[OMCC]

Originally Posted by Bonz

I used Jasco "Prep and Prime" for my 80G tank, very rusty inside. Put a half quart in the tank and filled the rest of the way to the brim with H2O. Let it sit a few hours, shook it around, let it sit another few hours, rotated the tank at different angles, etc. Nice thing is this stuff won't flash rust. Drained the tank, put a bit of gas in the tank and shook it around, drained again and put the hardware back on the tank and that was that! I got the 1 qt bottle of Prep and Prime at ACE, maybe similar stores stock it as well.

The metal rescue seems kinda pricey so I may try this first if the electrolysis doesn't work out. I searched the ace website for that stuff but couldn't find looks like I'll have to order it online.

[jetmechmarty]

Originally Posted by OMCC

The metal rescue seems kinda pricey so I may try this first if the electrolysis doesn't work out. I searched the ace website for that stuff but couldn't find looks like I'll have to order it online.

Too late. The reason to use Metal Rescue is to save what's left of the factory coating in the tank. Electrolysis already destroyed it, so save your money. Acid will clean it up nicely. You can even use vinegar. You're going to have to line the tank or it will rust quickly and everywhere.



For future reference, Metal Rescue is available at many Home Depot stores. It's about $25 per gallon.

[3Phase]

OMC,

I don't have a picture handy but the diaphragms in the fuel taps have one hole that has to aligned correctly when you put everything back together.

The hole is a small vent so the fuel shutoff will actually shut off when you kill the engine instead of sticking open while the vacuum slowly bleeds out of the valve.

.