MY XS' issues

[furthur69]

Hi, I have a '79 XS 1100. Very clean, original owner - 46K miles. Lately, she's been backfiring and dying albeit running perfectly until that happens. My plugs were carbonized as if my air filter had fuel in it when I started her. I put brand new ones in yesterday as they were black and she ran great all day. This morning - backfired and died a couple of times and then ran ok. I checked the plugs when I got to work and sure 'nuf they're starting to blacken again.

My fuel on/off petcock has been recently rebuilt and I even took it apart to inspect the o-rings and its solid. However, when you leave it in the on position for an extended period the air filter will fill up with gas and I have to empty and dry it before I can proceed. My friend - the original owner - said that he also rebuilt the vacuum pump and that that could be the issue as this problem started right after he rebuilt that and the fuel on/off.

I'm wondering if its filling up just a little bit even in the off position. Ideas?

Thanks.

James

[John]

The fuel i the airbox is caused by one or more float needle not sealing, AND the fuel distribution valve (octopus) not shutting off the fuel flow to the carbs. It is not a vacuum pump, it is a shut off/ distribution valve. If the PO rebuilt it with a K&L kit, then they are notorious for not having the proper diaphram in the octopus kits. If you doget fuel in the airbox, then it is very possible that fuel is in theoil also. Check the oil level, if it is high, and smells like gas, then drain it immediatly. The oil will wash down the bearings and tha ca cause more problems that you want to deal with. To find out which carbs are affected, pull the bottom of the airbox off, turn thr fuel on and observe which carb has fuel leaking from it. You may need to replace the float needle and seats. If they are leaking/sticking, then that may be the cause of the rich running problem. The 79 carbs are easy to replace the needle and seats in. They screw in, and are sealed with a gasket, as compared to the 80-81 carbs, which are pushed in and are sealed with an O ring which can leak, and cause a major problem when tring to remove the seat.

[furthur69]

Thanks John. I'll do those diagnostics and get back to you.

[furthur69]

John - there's fuel in the oil. The dealers don't understand what I'm talking about when I talk about a fuel distribution valve or octopus. I'm trying to ascertain whether that part is even available. If it's not, how do I rebuild the valve if the rebuild kit is faulty?

Thanks for your spot on diagnosis.

[jeffe]

From my own ^%&^$^$ experience also make sure that you do not have a float that is leaking and filling with gas. This will cause the same symptom

[furthur69]

Thanks. I will do the float leak test and replace as needed. That part btw is discontinued and K & L told me that I should buy a new rebuild kit and that I may have gotten a bad one. They can't be all bad they said or they wouldn't still be selling them - great.

[DiverRay]

You can also check the threads about doing away with the octopus. As I have a standard, I only have the two petcocks, and use only one. I would work on the carbs first, just get 4 new needles and seats and replace them. Reset the float level, and verify you don't have a bad float. That will probably go a long way toward solving problems.

Ray

[jeffe]

Check out Old Bike Barn i think they may have what you need http://oldbikebarn.com/ They do have them and floats if you need them.

[John]

The dealers don't understand because most of them have kids working the parts counter and they aren't as old as these bikes. it is called a Diaphram assembly and the p/n is 4H3-24520-00-00. I removed mine many years ago, and by doing so I can run on just one petcock. The only catch is to remember to turn the fuel on and off when riding. I have discovered that my bike will go about 1/2 mile with the fuel left off.

[pggg]

There is a not too difficult way to fix up those octopusses.
1. Carefully remove the octopus from the bike - taking extra care not to damage or scratch the unit.

2. Once removed, find a solid surface eg - a reinforced concrete pad, or, ideally, a large steel anvil.

3. Carefully place the octopus on the centre of the anvil. (you can see this coming eh John)

4. Find either - A: a large heavy axe, or - B: a 15lb sledgehammer.

5. Give yourself plenty of room for at least a 300 degree arc on your swing.

6. Muster up all available energy, and flatten the octopus flush with the anvil surface.

7. Delicately place the octopus in the trash.

8. All troubles and problems will now be over.

[John]

Hey Kiwi!


Octopus? We don't need no stinkin' octopus.

[furthur69]

All right I'm pulling the octopus now. I get the message I'm searching for re-hosing instructions. I found it once but now I can't for some reason. I remember something about two y valves. Thanks.

[DeanR]

If I've read correctly some people link the two petcock lines when removing the octopus.

John, is this the case for you so you can open just one petcock?

I just connected each seperately to the same side carb T. Has been working fine. I do turn on both petcocks.
By the way, when leaving the bike off for only say 5 or 10 minutes, should the petcocks Always be turned Off?

[TopCatGr58]

Hey Dean,

As long as your carb float needles are working okay, you don't "HAVE TO" turn off the petcocks when stopped for a short time. However, for several hours, overnight, etc., it's advisable to shut them off, don't want to rely solely on the float needles for keeping the gas from flooding and ruining your oil!
T.C.

[John]

Laxdad

[QUOTE]Originally posted by laxdad
[B]If I've read correctly some people link the two petcock lines when removing the octopus.

John, is this the case for you so you can open just one petcock?

Yes, this is how I have mine plumbed. I have capped off the prime ports on the petcocks, they are not needed. Fuel will flow in the on position. I only use one p/c until the fuel light comes on then I open the other to balance the fuel in the tank for a while before I need to switch them both to reserve. You shouldn't have any fuel starvation problems until you hit 100 mph or so, but just open the other p/c and you'll ave plenty of fuel available.