Octopus Woes - My Journey

[johnstewart]

Dang, I love this bike. I have to say that before speaking badly of it, but yeah it's been a great bike. Have close to 40k on it after buying it with 11k, holy cow close to 20 years ago now! 1979 XS1100SF, originally black, but now red (I put on a tank/badges from a donor bike a couple of years ago)

Well, after all these threads I've seen about octopus problems, I'd never had one... until a couple of weeks ago. I noticed I smelled terrible after riding into work. I figured an exhaust leak or something. I finally got around to diagnosing, and noticed that the octopus was weeping gas out the side while the bike was running... I was getting gas splashed back up onto my clothes, whoops!

I was also having problems logging into this forum (was getting "database error", eek!), so had to go off of only old posts. Somehow I managed to get logged in this morning, though, so now you get to hear my tale.

Well, I thought, okay, it's only weeping a little, the screws didn't seem so tight, so I disassembled the octo, all the rubber looks good to me, reassembled and put it back on. NOW the gas was SPEWING out the side, ack!

Okay, plan B.

Armed with many threads and diagrams, I gathered fuel line, dug out some fuel filters I had, and went to replace the octo.

http://www.xs11.com/forum/showthread.php?t=3878
http://www.xs11.com/forum/showthread.php?t=6581
http://www.xs11.com/forum/showthread.php?t=525
http://www.xs11.com/forum/showthread.php?t=27434

First off, I don't know where the heck y'all found a Y fitting for a 1/4" fuel line, but they DO NOT exist at any of the SEVEN different auto parts stores and one hardware store I went to locally. I did find a couple of T's, but no Y's. Even finding them online has proved nigh-impossible. I did find some Y fittings meant for vacuum applications, but the ones I found either didn't say the material, or were marked PVC plastic, which is not good to mix with gasoline, as I understand.

This is the closest I could find online.
https://www.qcsupply.com/130205-barb...tings-1-4.html

I really wanted to ride last weekend, and these would take a while to ship, so I proceeded without the Y's.

What I did was cap off one output of the petcocks with a hacked together plug. I took a short piece of fuel line and plugged it up with a little piece of metal and some JB Weld. Hacky, but effective. Is there a better way? I see in one thread someone suggesting they just connected the two Prime nipples to each other; probably what I should have done.

I ended up with something similar to the 2nd-to-last picture here:
http://www.xs11.com/forum/showpost.p...6&postcount=13

From one nipple on each petcock, under the boot, to a fuel filter, then around the boot again... but I had to go UNDER the boot again because the input to the carb is facing down. The diagram says:

"Swivel the fitting to an upward position"

On each of my (Mikuni) carbs, I tried twisting them up... but they didn't want to budge, and I didn't want to break them.

Can I really swivel these up? Is there a trick? Do I need to loosen something up before I do?

I used the Prime (front) nipple from each tank. But now that I'm going back and re-reading, I guess I should have picked the On/Reserve setting. I guess I thought these might depend on the vacuum feed from the octopus, but now that I think about it, that doesn't make sense. Easy enough to swap.

It all worked great! I did notice that the fuel filters (between the boots, wired so the fuel is flowing up) seemed to still have air in them.... which seemed weird. But it worked great! Did a nice long ride on Saturday... probably 75 miles or so. Awesome.

Took the time to repair some other things (I had a bent up rear fender, I finally replaced along with a banged up turn signal). Washed it for the first time in a decade, looks great!

I went to hop on this morning to ride to work... I realized I left the petcock on Prime (whoops, hard to get into the habit of switching that each time). OK, well, started firing it up and it wasn't catching, and I smelled gas! Crap! I looked underneath and couldn't tell yet where it was leaking, but it's leaking from somewhere. Crap!!!

So I gave up and drove in in my car instead. Boo.

I'm not sure yet what's up. I guess perhaps the float bowl was overflowing on one of the carbs. But I'd have expected more gas than what I saw... why would it only leak when trying to start it?

Worried about gasoil, I didn't do any more. I'm going to change the oil before trying to fire it up again.

Now this has me thinking I should revisit the octopus... like I said, the membranes all looked in good shape and solid. There was some crud on one of the plastic pieces, which I cleaned off.

I suspect I just reassembled it badly... because I can NOT find a dang assembly diagram for it, and wasn't careful to document when I took it apart. So I guess that's another question... how the heck do you assemble the octopus?

So here's a summary of my questions, after the above novel:

- Any other recommendations for a Y fuel line than this? https://www.qcsupply.com/130205-barb...tings-1-4.html

- Does anyone have instructions/diagram on the assembly of the octopus?!?

- Does anyone have a link to an octopus rebuild kit? (I'm not seeing anything at partsnmore)

- Can I really move the fitting for the fuel input to the (Mikuni) carbs to point up instead of down? Just twist really hard??


I like the simplicity of the no-octopus solution.

I don't like gas spilling all over when I forget to switch petcock to Off.

[jetmechmarty]

I like the simplicity of the no-octopus solution.

I don't like gas spilling all over when I forget to switch petcock to Off.

Does this mean you're fixing it or deleting it?

K&L makes kits for these. Often the kit comes with parts for the vacuum shutoff valve and both petcocks. Several vendors have them. Try George Fix. XJBikes.com has a very good tutorial on repairing Yamaha Fuel Valves. It's probably reposted on this forum.
My experience says the o'ring in the kit is the wrong size and won't seal. You'll need a thicker one.

Plumbing guide is on the bottom of your seat or in the parts catalog.

Disregard all of this if you're getting rid of it.

[johnstewart]

Well, I went to go dig in tonight... I was going to delete it, and try to find out why I was getting a leak.

I had a spare set of carbs I pulled off the shelf to look at to see why I couldn't move the input fitting.... and it turns out the octopus was still connected to the spare carbs!

I decided to try and put it back, so I pulled my fuel line hack back out, installed the octo... and it works! I would still like to find a diagram showing how to reassemble.

> K&L makes kits for these.

I could not find them on the site just now; I scrolled through all the Yamaha fuel motorsport stuff. What am I even looking for ("octopus" is likely not it)?

Have you seen a diagram/rebuild instructions anywhere? It may be a moot point

----

Anyway... it turns out I've now identified my REAL problem... the issue is carb #3 is leaking gas when in Prime position, or when the bike is running in On position.

I've never done any carb work, but I DO have the spare set. I had the local shop "do the carbs" 20 years ago when I bought the bike, and I think they didn't do a great job (gas mileage has always sucked).

It seems like the float bowl is overflowing... is there a "simple" fix for this? I'm going to start hunting through the forums here.

Looking in the Clymer, it looks like I've got to take the carbs completely off the bike to even open up the float bowl.

I'm guessing the needle/pin must be gummed up somehow. Can I clean/fix this without doing cleaning ALL the carbs?

thank you!

[sethhope]

You can't easily clean the needle and float assembly without removing the carbs from the bike. However, removing the carbs is a really simple job, and it doesn't require a whole lot of know how. Remove the fuel and vac lines, disconnect the throttle, loosen the boots and airbox, and the rack of carbs should all slide out together.

Flip the carbs over, remove the bowls (4 screws). Gently tap out the pin holding the float in. Try not to pry too hard, sometimes those posts can crack off. Remove the floats and unscrew the fitting under the float tang. Out comes the needle valve.
While youre in there, it wouldn't hurt to spray some carb cleaner through your main jet and through all the holes and passages. If you have some time, I recommend ordering a gasket kit (or at least a bowl gasket).
Reassemble the same way you took it apart.

To put the carbs back on, slide the carbs back in, push onto the boots on the engine, attach the boots on the airbox. Connect the vac and fuel lines and throttle cable. Tighten everything down, and fire her up.

[johnstewart]

Flip the carbs over, remove the bowls (4 screws). Gently tap out the pin holding the float in. Try not to pry too hard, sometimes those posts can crack off. Remove the floats and unscrew the fitting under the float tang. Out comes the needle valve.

I'm looking through carb posts now (like this Cleaning 101 post: http://www.xs11.com/forum/showthread.php?t=35974), and I think I'm with you to this point.

Once I get the needle out, then what? Spray carb cleaner all over? polish the needle valve somehow?

thank you!

[sethhope]

I'm looking through carb posts now (like this Cleaning 101 post: http://www.xs11.com/forum/showthread.php?t=35974), and I think I'm with you to this point.

Once I get the needle out, then what? Spray carb cleaner all over? polish the needle valve somehow?

thank you!

Idk if im doing it the "right" way, but i usually just saturate in carb cleaner. Sometimes, depending on how filthy my carbs are, ill rub it with a cotton swab. Usually its just ethanol gunk thatll cause sticking. Id also drop your floats in a bowl of gas and make sure theyre not leaking or sinking. Also make sure they arent catching on the bowl gasket.

[johnstewart]

Sounds good; going to (gulp) try to pull the carbs off tonight.

[sethhope]

Sounds good; going to (gulp) try to pull the carbs off tonight.

Good luck! If you need anything, give me a shout!

[johnstewart]

I can see now why people get rid of the stock airbox just to make it easier to get to the carbs, holy cow. Seems like going back in, go in with octo disconnected would be easier and then hook up all the fuel lines after the carb is in?

So despite the many dire warnings, I busted the post getting the pin out of the float. I tried PB Blaster, soldering iron, using a blade to get under the head, it was STUCK.

At that point, I was tempted to put the spare carbs I had on the shelf on the bike to see what would happen, but I see one of the big piston things isn't freely moving on those, so I didn't try that. Supposedly the bike they came off of ran like a top when it was crashed 20 years ago (it did sure have a nice looking tank, small dent excepted, so I put it on my bike).

Wasn't there some carb refurbishing guru somewhere who'd get your Mikunis into tip top shape? Is there anyone doing that any more?

Anyway, I cleaned it out with most of a big can of carb cleaner, squirting it in all the various orificies I see. Seems pretty clean.

I JB-Welded the broken shaft back on; I'm hopeful this'll hold. Anyone successfully do similar?

Video I made of the situation: https://www.youtube.com/watch?v=3kd3dmpPBGw

What I do see is that it despite it being close to the right height of 1.014" (as I recall, not that I can bloody measure that closely), I think the float is clanging into the carb housing. And I guess therefore never hitting the pin hard enough to seal it shut. I wonder how long this has been slightly leaking.

Seems like I need to "bend the tang" according to Clymer, eh?

[jetmechmarty]

The JB Weld repair will eventually fail. For me, it resulted in a fire.

[sethhope]

A gasket kit and clean may be worth it on the other carbs. If you're feeling ambitious, you could just swap the single carb body.

[johnstewart]

The JB Weld repair will eventually fail. For me, it resulted in a fire.

Ack! Tell me more about this; what happened? I guess the float bowl overflowed?

[jetmechmarty]

Ack! Tell me more about this; what happened? I guess the float bowl overflowed?

I bought the bike with the repair in it, so I don't know how long it held. The bike had been in winter use. I turned on the fuel and did not notice the fuel running out. I thumbed the starter and BOOM! Backfire caused it. I was in the garage, so priority was backing the flaming bike outside. My daughter saved the bike. She was very quick with the fire bottle.

No, I would not repair a carb with JB Weld. Andy's Motorcycle Obsession on YouTube did a proper fix. I had mine welded. $100. Or buy a replacement body.

[johnstewart]

I bought the bike with the repair in it, so I don't know how long it held. The bike had been in winter use. I turned on the fuel and did not notice the fuel running out. I thumbed the starter and BOOM! Backfire caused it. I was in the garage, so priority was backing the flaming bike outside. My daughter saved the bike. She was very quick with the fire bottle.

No, I would not repair a carb with JB Weld. Andy's Motorcycle Obsession on YouTube did a proper fix. I had mine welded. $100. Or buy a replacement body.

Wow! You're saying this Andy Youtube guy did the weld for you?

[jetmechmarty]

Wow! You're saying this Andy Youtube guy did the weld for you?

No. Andy is in Tasmania. My carburetor post was welded in Atlanta. I believe this all went down about 14 years ago. I'm sorry for the confusion.