other octopus topic, I know I know

[Bauer]

Hey all, sorry to add another octopus thread to the block, but after spending some time in the search. I think ive drawn enough of a blank that I need to post here....

I have been having a problem with the bike smoking on startup after an extend ride ( 15 miles steady) versus no smoke after short jaunts. Plug inspection returned that 1&2 were wet, 3&4 dry, all black, with a little white on 3&4.
Went out to start it tonight, no smoke after sitting for a week. But I think I may have figgered out why the 1&2 plugs are wet, and 3&4 are dry. For some reason the "octopus" on the bike appears to be not letting fuel into the 3&4 carbs. Its letting just enough to keep it running but not enough to keep a supply on a hard pull.

If turning the petcocks to prime, it lets some fuel in, but not enough to even fill the inline filters half full. I can compare it to a garden hose. If the flow is minimal you can see at the end that it does not completely fill the inside of the hose (-) [ the dash being the level inside the hose ]. Im no genius, but when turning the petcocks to prime, shouldnt there be a massive rush of gas that completely fills the hose.

If removing the fuel filter, it lets some fuel flow, but again, very little compared to the gush that should be coming. So thus eliminating the filters and the carbs themselves.

I have yet to determine if its the "octopus" that is bad, or if the in tank filter on the petcock is possibly plugged thus not letting fuel out at all.

Would this in turn cause one side or the other to smoke after I start it after a long ride. Then, while sitting, the bowls, as well as filter fill back up, and walla, I have gas at the plugs again, thus burning the excess (or lack thereoff) residue in the cylinders off?????

Sound logical, or am I just blowing smoke.

PUN intended.

If it is in fact the octopus, whats the most recommended way of eliminating it.

Thanks.

[John]

Run a line from the left petcock to the right bank of carbs, and a line from the right petcock to to the left bank of carbs. This method will allow for gentle bends in the fuel line, and the lines wont kink. That is how I have mine plumbed right now. Concerning the flow rate... with the tank off the bike, attach a line to the petcock and see how fast it drains into a bucket. Will it drain a gallon in a half hour? When it's running, it only uses a gallon per half hour, if you think about. That is 30 MPG.

[Bauer]

My first suspicion was that the lines were kinking, but after inspection, all have gentle bends and appear to work fine.

But you did just give me an idea. I think Ill try to hook the left petcock up to the right side bank of carbs and see if I can switch the problem from side to side. Then I can verify that it is the octopus.

[trbig]

If it is in fact the octopus, whats the most recommended way of eliminating it.

3 steps back... jump shot into the trash can! Seriously... not kidding!. lol.

There's no need for it if your petcocks and float needles are working. As an extra precaution, you could turn your fuel off every time you're done riding.
As far as expecting Prime to flood the tubes... it will until the bowls are full of fuel and your float valves shut it off. Prime just makes it easier to fill your bowls with fuel after they have been drained for one reason or another. I have never had to use it. Even after cleaning the carbs and the bowls are bone dry, I just turn the gas to ON, wait a few seconds, and crank her up.

Tod

[Bauer]

Right, floats will shut the flow off, once they are full, but after draining the bowls, the octo will not allow the fuel to flow to fill the bowls.

Not that I need the prime, just an observation while trying to diagnose the problem.

[mro]

originally posted by Bauer
I have yet to determine if its the "octopus" that is bad, or if the in tank filter on the petcock is possibly plugged thus not letting fuel out at all.

If fuel not flowing outa petcocks either petcock or filter cloged.
If you got wet plugs before you start engine then float needle(s) and possible octopus not shutting off fuel.

Do have the octopus for my LG, but too many other projects have been putting it on hold, so...........I could be all wet



mro

[Bauer]

Carbs are freshly cleaned by a professionial (not me ) , so doubtfull it is carb related, I can see in my inline filter that I am not getting fuel flow to the bowls. It is something between the tank and my inline filters.

[mro]

Carbs are freshly cleaned by a professionial

If fuel in cylinder when NOT running it's got to come from somewhere, and it's got to get past float needle.


mro
Cleaned my 80G carbs and ran without problems for over 3,000 miles. Took first small trip on bike, (only 350 miles stopping just for fuel) bike ran great, got home and parked in garage. Next morning started to pull it out and smelled gas. Bottom of air box was wet. Found that fuel line from filter to carb (had not replaced) deteriorating and tiny bitts of rubber fouled the float needle.

[Bauer]

if you re-read what I originally posted, #'s 1&2 are wet, 3&4 are dry. I am not worrying about 1 and 2 yet, until I figure out why I am not getting any fuel through the lines to 3 and 4.

When the carbs were cleaned and tuned, I fully replaced everything that I was capable of doing so to prevent downtime in the future. EXCEPT for the octopus as I knew of no better way to take care of it.

Now, assuming (have not checked yet) that the petcocks are letting fuel into the octopus, the octopus is NOT letting fuel to the right side rack of carbs. The inline filter I have going into those cylinders gradually acquires fuel if sitting over time, but does not provide a steady enough flow if the bike is running thus giving me the dry plugs for the 3 and 4 cylinders.


Thus, by process of elimination, and a whole lot of typing, I have basically figured it out


Now if I removed the petcock from the carbs. Do I simply Y the run and prime together, then into the carbs?

Secondly, if I have leaky petcocks, but the float needles are sealing, is there a worry for excess fuel where there shouldnt be? Im not one to want to have to shut the petcocks off all the time, and they leak in the off posistion anyways, so it wouldnt do me much good.

[prometheus578]

Float needles should stem the flow of fuel from a free flowing fuel source, but sometimes they won't. they may be in good enough shape to function properly when the bikes is consuming fuel(a little leakage, but may not really seal, and leak over the course of a few days or weeks.... to a point where leaking fuel is noticable.

but not enough to even fill the inline filters half full

Many styles of in-line filters , like the disk ones, or the cone shaped ones... parts of the filters are higher than the line itself. What I mean is... you have a 3/8 fuel line, and the outside diameter of the filter is an inch. Many times there will be a pocket of air trapped at the top, hence it doesn't look like it is filled. It will usually only fill to the level that was in the hose. So... just 'cause you see air, or the filter doesn't look full to you, doesn't mean that it's not taking it's full flow.
Here... think of a garden hose attached to some sort of clear glass globe, with an exit hose out the other side. Turn on the hose. You'll see the water filling the globe.... but it will only fill to the hieght of the exit hose, and fill no more as it's now running out again. (There will be an air pocket at the top)

[prometheus578]

Now... the situation will be different if inside the globe, there is a compressed spring. Then in that case..... Oh, sorry.. wrong thread.

My computer loads slowly. Nice avitar, Bauer

[Bauer]

right Prom, but now in watching the fuel flow from the octopus to the filter to the carb, fuel does not flow fast. It is a whole new world over what is flowing out of the 1 and 2 side. That filter is half full, but I cant even get the right side to that point because the gravity flow to the filter is not high enough to push it anywhere, bike running or not. thus starving 3 and 4 of fuel.

[Bauer]

unfortunately time wont let me take it apart this week. Next week its off to my good friends, the carb professional (senior technician at a powersports dealership) and then diagnose from there. Ill keep you guys informed.

[prometheus578]

"Don't worry, he'll understand"

To rule out the petcocks, get two pieces of fuel line of equal lengths. Attach them to the petcocks and point each line to two rows of lit candles on the garage floor. Turn on the petcocks. Fuel from both of the lines should stream out the same distance, and extinquish the same amount of candles.

(Hey... I'm not legally liable for advice I give, am I?)
Ok... Bauer... fill your fuel tank with water first, in stead.

[John]

Petcock screens

I would take a look at the tower screens on the petcocks. The problem may lie there, or in the petcock itself. The screen may have fallen off the petcock, and some debris may be blocking the inlet to the petcock. Pull the tank off the bike, and depending on the amount of fuel that's in it, you can tilt/prop the tank forward to uncover the petcocks. You can then remove them, and disassemble them. There may be some crap in the passageway in the petcock itself, or the rubber disc that is inside the petcock may have broken down, and some of the material may be blocking the flow. It's got to be something simple.
If you do remove the octopus, then just go to an auto parts store and get two, quarter inch vacuum caps, and cap off the prime port of the petcock. It will be the forward nipple on the petcock. You won't need it for any reason. I would replace the fuel lines at the same time. I use a 1/4 inch urethane hose, not polyurethane. That will breakdown after a while of being exposed to fuel.