no octy??

[old_skool]

Ok, what the hell does the octy do that i need it?? Can I remove it, toss it in a coffee can? I want to replace my petcocks with a standard on/off/res single drain on each side, can I do this and lose the octy? Has anyone done this before, I don't have any leaks, I'm not wanting to tap or bypass or..., just lose the ugly critter and double hung petcock.
Thanks! Rich

[cywelchjr]

Just losing the octy and plugging the prime outlet will give you standard on/off petcocks which is really what the special has, the octy is there to give the vacuum operated on/off function of the standard. Some guys just run a hose between the prime ports from one side to the other (just in case they get stupid and flip them to prime so no gas goes out onto the ground) but you can just plug them.

Then you just run the rear spigot on each petcock to the carbs, many run them to the opposite side because it makes it less likely for the line to get pinched and also makes it easy to just turn the tank around for tuning.

[bikerphil]

The octy also serves as an emergency fuel shut off in case the bike falls over. When the engine stops via the tip over switch, fuel supply is also cut off. I removed my octy many years ago but since have gone to a Pingel inline vacuum shutoff that has just an in, an out, and a vacuum hookup. To me the auto shutoff is insurance against a crankcase flooded with gas.

[old_skool]

Do you need both outlets on the petcock to have reserve, if so, can you just tee them together and run them to the fuel hookups on the carb, I really like to know if anyone has replaced these petcocks with the single feed ones, if none fit, I think I'm going to get a spare tank and have fun with the welder(should I remove the gas first) oh, yeah, this is a 79 SF, just started tearing it down today, will start to clean the carbs tomorrow, already removed them, also, plan on using pod air filters, what if any jet changes and internal changes will I need to do, since I'll already have them apart.

[bikerphil]

Block off the front spigot on each petcock and using the rear ones will give you on and reserve.

[old_skool]

So its actually a 4 way, didn't pay that close attention to it yet. What is the prime setting actually for, or just what is says, you prime before switching to the normal flow?? A lot of big bikes today only have one petcock, why did Yamaha need 2?

[bikerphil]

The prime is for filling the bowls when they are dry bypassing the vacuum shutoff octy. The way the tank is designed, there is gas in the two sides of the tank and a high spot in the center thus two petcocks are required to access all the fuel. I just run the left side one and have the right blocked off with a plate so my range is a little less than if I were using two.