OCTY or NO OCTY?

[kboehringer]

XS11 Folks,
I am rebuilding the carbs on one of my XS11's and the OCTY appears to be in real bad shape requiring replacement diaphragm, hoses, etc. The presence of an OCTY also makes carb removal that much more complicated.

I have two other XS11's and neither had an OCTY when acquired. I had no intention of going out of my way to purchase one for either of those bikes. On those, I performed the MOD to tap and plug the PRIME ports with a set screw and filled the PRIME fuel tunnels with RTV then capped them off. There is no way they can leak through or allow the fuel to overflow the bowls. That "Mod" could be reversed, but I have no intention of ever doing so. It has also provided a very certain second OFF position which has eliminated most leaking possibilities from those two bikes.

I know the purpose of the OCTY is to shutoff fuel when the bike is not running. Obviously this would be handy in an accident. But, I figure if I've been in an accident I probably have bigger concerns and if the tank is damaged in said accident the OCTY isn't gonna help there anyway. I think my bikes are probably better off with a sealed PRI tunnel and a set screw. I'm totally in the habit of turning the fuel to PRI on shutdown so forgetting is possible, but not likely.

I believe some folks are advocates of the OCTY while others would toss them in the trash in a minute.

I'd like to be further convinced that tossing this thing to the side (not trash) is truly the right choice?

Respectfully,
Kurt

[madmax-im]

They're not hard to rebuild...I dont see the problem with having them...My XJ had one and as far as I know its still on there and never had a problem with it...you already have 2 bikes without the Octy so in my opinion you already have real world info as to how good or bad...IMO you prolly could do fine without it... Since your bikes are not 100% OEM i wouldnt worry about it...but if you are restoring a bike to factory specs then i would....

[BA80]

I used to feel as Ben does but having that thing go south on me twice on long trips, it's in the parts pile in the garage.

As long as your float valves and float height are right there's no problem. Been running mine like this for years. Just cap off the front nipple on the petcocks. It's just for the prime function and is unnecessary without the octy.

[kboehringer]

OCTY headed for the junk pile.....

I used to feel as Ben does but having that thing go south on me twice on long trips, it's in the parts pile in the garage.
As long as your float valves and float height are right there's no problem. Been running mine like this for years. Just cap off the front nipple on the petcocks. It's just for the prime function and is unnecessary without the octy.

Greg & MadMax,
Thanks for the input. Since this Mikuni set is going on my bike that will be a long hauler, the prospect of that over engineered 35+ year old gizmo going south on a long trip was the point I hadn't considered. Also, as MadMax stated, my bikes are not perfect restorations like the work MikeP does. My bikes are all "RESTO-MODS" (on one level or another) so a missing OCTY is not causing me any pain at the show judge's booth! It's headed for the parts pile!

I'll use the set-screw mod combined with the cap. The caps we can find are really air caps and don't stand up to the little bit of gas that could be sitting in them or a long period of time. With the set screw installed the cap is only there for looks.

Greg, I REALLY like that balance tube set-up you have ..... I think you'll be seeing that on my bikes one day REALLY SOON!

Thank you again,
KURT

[BA80]

Greg, I REALLY like that balance tube set-up you have ..... I think you'll be seeing that on my bikes one day REALLY SOON!

Thank you again,
KURT

Ha ha ha, I came up with that because riding north to KC once I had to switch to reserve and about 5 miles later I ran out of gas ON 1 SIDE! Rode the next 10 on 2 cylinders struggling on hills and such.

Made it to the gas station and coasted to the pump.

[motoman]

Greg & MadMax,
Thanks for the input. Since this Mikuni set is going on my bike that will be a long hauler, the prospect of that over engineered 35+ year old gizmo going south on a long trip was the point I hadn't considered. Also, as MadMax stated, my bikes are not perfect restorations like the work MikeP does. My bikes are all "RESTO-MODS" (on one level or another) so a missing OCTY is not causing me any pain at the show judge's booth! It's headed for the parts pile!

I'll use the set-screw mod combined with the cap. The caps we can find are really air caps and don't stand up to the little bit of gas that could be sitting in them or a long period of time. With the set screw installed the cap is only there for looks.

Greg, I REALLY like that balance tube set-up you have ..... I think you'll be seeing that on my bikes one day REALLY SOON!

Thank you again,
KURT

It would cause you a lot of pain if you forgot to shut them to PRIME and the float needles didn't seal off good. Then you could and would have fuel bowls overflowing down on a hot engine. That kind of result could turn into flames!.......not good my friend. That makes for TWO safety features for the Specials, the one you mentioned and the one I stated! Having the Specials with the octys IS the better choice. The Standards have the vacuum shut-offs built into the petcocks so a fuel bowl overflow from bad sealing float needles doesn't take place.......and no, the petcocks will NOT interchange between the Special tanks and the Standard tanks. The tanks between the the two models WILL interchange though.

[madmax-im]

Hey Greg...I do like that setup...

[BA80]

It would cause you a lot of pain if you forgot to shut them to PRIME and the float needles didn't seal off good. Then you could and would have fuel bowls overflowing down on a hot engine. That kind of result could turn into flames!.......not good my friend. That makes for TWO safety features for the Specials, the one you mentioned and the one I stated! Having the Specials with the octys IS the better choice. The Standards have the vacuum shut-offs built into the petcocks so a fuel bowl overflow from bad sealing float needles doesn't take place.......and no, the petcocks will NOT interchange between the Special tanks and the Standard tanks. The tanks between the the two models WILL interchange though.

Beats the devil out of a blown octy spraying fuel all over under the tank running down the road which is what happened to me.

Like I said, as long as your float valves are good and the floats are set right it's fine. I don't even need to turn mine off and I have the brass float needles.

[motoman]

Yep Greg, float needle valves sealing OFF correctly are key to not having fuel runnin' everywhere from float bowls when bike is shut down and forgetting to shut petcocks to prime when mods have been done to petcocks instead of using a KNOWN TO BE GOOD octy.

[BA80]

KNOWN TO BE GOOD octy.

They're ALL good until they're not.

[motoman]

They're ALL good until they're not.

That be related to murphys-law kinda-sorta.

[TopCatGr58]

Hey Kurt,

Just put another manual TURN OFF valve in line like BikerPhil did to provide that second layer of protection against a failing petcock AND failing float needles. Much more reliable than a spring/vacuum controlled OCTY.

My other concern is that you put RTV in the petcock towers submerged in fuel all the time! Regrettably almost any epoxy based sealant like JB WELD and such also have been shown not to hold up in gasoline/ethanol full time!

A quick net search has revealed a few suggestions, ie. Hylomar; Permatex; Yamabond??

T.C.

[kboehringer]

A better explanation....

...SNIP..
My other concern is that you put RTV in the petcock towers .....SNIP
T.C.

TC,
Sorry, I did not explain that correctly. I put RTV in the drain port BEHIND the set screw mod and also up the unused line connector, not in the towers. The RTV should probably never ever see even a drop of gas. The set screws were also coated with red lock-tite before install as well.



I had read somewhere on this board, probably in the mod write-up that some folks had just gone and stuck an air cap on the unused prime port when they removed an OCTY. A little bit of gas found a way to rot away the air cap. I didn't want any chance of that

Respectfully,
KURT

[XJOK2PLAY]

Hey Kurt,
My 2 centavos worth...

When I first bought my Maxim, it needed a lot of work.
The tranny was shot, and it had a huge oil leak out the lower back center at the base gasket. (The PO had stuffed a big towel back up in there to absorb the oil gush!)

The bike was in Cody's garage, and I bought the bike from Miles Baker. He had been fixing the bike up, which had endured a really rough life before he got it. But he'd gotten to a point where he decided to sell it just as I came along and wanted to buy it.

Cody called for reinforcements, and this was the first time I met Tod Bigelo and Bohn Frazer, around the first of 2009. Without knowing me, (but because they knew Cody,) and loved these old bikes and enjoy getting them back out on the road, they came to Cody's, gave up an entire weekend and helped me. It just so happened that at that paticular time I had just gone through a divorce after 27 years of marriage, and had pretty much lost everything. Needless to say, I was blown away by their generousity to help a total stranger. And, it was there I met 2 great new lifelong friends... guys I now proudly call "my brothers."

Now, for the funny part...
As we started to tear the bike apart, one of the first things Cody did was to rip the Octy off, and as he slung it across the shop, he announced "We don't need this POS anymore!!"

Since this was my first time to work on a Jap bike, needless to say, it freaked me out just a bit! Actually... panic was a more accurate description! Lol!

They told me all I had to do was not forget to shut the petcocks off when I parked the bike overnight... just as a precaution. No biggee, right?

Well... over the next 4 years and 40,000 miles I owned that bike, there were a few times I forgot to do just that.

Yes, my float valves were bad. Yes, it overflowed... both into the airbox, saturating the air filter, and into the oil.

Luckily, each time it happened, I caught it before starting the bike! I'd have to tear the air box apart, dry out the box and filter, remove the oil cap... smell the crankcase for gas odor... then change the oil. Yes, you could tell gas had flowed into the oil.

Yes, it was a PITA sometimes. But later, when I put my Dynajet kit in, and had to pull the carbs about 7-8 times to get everything right... I NEVER missed that obnoxious tangled snake pit of hoses being in the way to deal with.

I understand the Octy's purpose and function... but good grief are they a mess of hoses. Plus, it just makes it look so much cleaner and better w/o that crap in there, IMHO. YMMV, though.

Good luck on your build, Kurt... whichever way you decide is right for your bike.

After seeing pics of your other bikes, I know it'll be a beauty.
Ride safe!
Bob

[BA80]

GEEZE BOB........you can be long winded. Had to get up and get another beer in the middle of that post.