My bike has been running funny. Jerking and sputtering, uneven idle and backfires sometimes. In short, not well at all.
Last time I went for a ride it started to act up really bad. At one point it even died on me when shifting down at an intersection.
I made it back home and it ran poorly all the way.
Yesterday I went out to the garage to take a look.
I started the bike up, and it sounded awful! Black smoke came out of the exhaust, it ran extremely uneven and the sound was like if it was gasping for air, almost like you would try to drown it in water.
I have experienced a car with the same behaviour, so I did what I was taught and checked the oil first. The dipstick was wet up to the lid and rank of gasoline. The crankcase was flooded with fuel.
Obviously one or more carbs have leaked fuel down inte the crankcase vent.
-This is odd, since I cleaned out the carbs a month ago at the same time when I replaced the airfilter.
The floaters moved freely and the bowls were clean and nice. The floater needles looked ok as well.
Besides, the gashandle was completely stuck and could not be moved.
I dismantled the gaswire from the handle to see if the handle was jammed, but it was ok, and so was the wire. I traced the problem down to the carburettor.
So I removed the brand new airfilter/box and found lots of silicone chunks and debries loose in the airbox.
When I removed the airfilter, I found the carburettors all gooed up by melted rubber.
The silicone lining in the airfilter is all dissolved
However, there is absolutely no scent of burned rubber.
Even though I admit it looks like there´s been a fire, I doubt it.
What the hell happened here? The intake rubber feel spongy at the touch, like it has been dissolved by acid, and not crusty or sooty like one would assume it would be if it had burned.
The carbs are in such a state that I am not even sure they can be saved.
I´ll try to clean them out and replace what ever parts avaiable on the market, but hopes are low at the moment...
Sure looks like a fire
Its there a lot of e ethanol in the petrol where you see? Help us out to help you by updating you profile please.
Quote from: "Sin_Tiger"Its there a lot of e ethanol in the petrol where you see? Help us out to help you by updating you profile please.
Hi Sin, thanks for the input!
I live in Sweden, and our gasoline is European standard I guess.
But I do not think that is an issue. Besides, these rubber parts must be manufactured to resist gasoline and such.
Otherwise I would not be the only one with this problem.
My guess, stuck float causing floading which for some reason resulted in fire.
I´ve had stuck floats two times, both after I had the carbs off and dismantled. My guess is the needle gets stuck in the process. First time it loosened by itself, the second time I had the carbs apart again. The float wasn´t stuck when I opened the carb, so it probably loosened its grip in the process.
Find a replacement carburettor and buy a new air box, sounds to me like the way to go.
Even though there's no burning smell I still think its burned like you already guessed, just a chemical burn. The trouble is figuring out which chemical, which is why I asked about the ethanol.
I seem to remember reading somewhere that Sweden has E85?
I'm wondering now if its been a bit more complex with more than one chemical, acid? Alkali? Not much more help I'm afraid mate.
Quote from: "Rocinante"My guess, stuck float causing floading which for some reason resulted in fire.
I´ve had stuck floats two times, both after I had the carbs off and dismantled. My guess is the needle gets stuck in the process. First time it loosened by itself, the second time I had the carbs apart again. The float wasn´t stuck when I opened the carb, so it probably loosened its grip in the process.
Find a replacement carburettor and buy a new air box, sounds to me like the way to go.
-Yes that is my guess aswell, it was probably my fiddeling that caused the carb to flood in the first place since it was ok before I took it apart.
Is there anyway to check that the assembly was correct after a teardown?
I.E can I make sure the bowl keeps tight before putting the carbs back into the bike?
I have begun cleaning out carb 1, the dirtiest one. Removed all plastic and rubber parts and cleaned the housing with thinner and a toothbrush. (The toothbrush has some siliconedetails, or should I say
had, as they dissolved in the thinner.) But the carb is actually coming out a lot cleaner than I was hoping for.
Still, there are small holes and spaces that I can not get to with a brush, so a ultrasonic will be needed.
I located an ultrasonic cleaner with a capacity of 2 Litres at a dealer for just about 100€ (145$) I´ve been looking at one of those anyways, so now is probably a good time to get one.
Thanks for the input Rocinante.
Quote from: "Sin_Tiger"Even though there's no burning smell I still think its burned like you already guessed, just a chemical burn. The trouble is figuring out which chemical, which is why I asked about the ethanol.
I seem to remember reading somewhere that Sweden has E85?
I'm wondering now if its been a bit more complex with more than one chemical, acid? Alkali? Not much more help I'm afraid mate.
Yep, that is true, we do have E85 at the gas station if one wants.
Some people here run 70% gas and 30% E85, to boost combustion.
But I do not, and especially not in my bikes.
You are probably on to something there, I repaired the snorkel-fitted airbox with chemical resistant silicone glue, the best allround glue I know of, as it had let go in the joint between the two halves.
And that glue had also turned into molecules aswell...
More info coming...
Thanks man!
The lack of a burning smell is odd, because the pics point to backfiring through the number 3 carb lighting the leaking fuel and melting the rubber which then affected number 2.
On the other hand, I've seen chemical burning of brass before but not aluminium so can't comment on that hypothesis. The brass burn was a complete surprise; I'd turned up and polished a pair of brass candlesticks while the chippys made a wooden presentation case lined with green beize. The beize was glued in with PVA. When we opened the box the next day to show off our work prior to the presentation the candlesticks looked about a hundred years old - all blackened and pitted. We put it down to the acid fumes from the PVA and did some very hurried repolishing. But to come tothe point, they looked the same as that no3 carb.
Quote from: "Bixxer Bob"The lack of a burning smell is odd, because the pics point to backfiring through the number 3 carb lighting the leaking fuel and melting the rubber which then affected number 2.
On the other hand, I've seen chemical burning of brass before but not aluminium so can't comment on that hypothesis. The brass burn was a complete surprise; I'd turned up and polished a pair of brass candlesticks while the chippys made a wooden presentation case lined with green beize. The beize was glued in with PVA. When we opened the box the next day to show off our work prior to the presentation the candlesticks looked about a hundred years old - all blackened and pitted. We put it down to the acid fumes from the PVA and did some very hurried repolishing. But to come tothe point, they looked the same as that no3 carb.
That was my first thought aswell. A backfire flame through one of the carbs that ignited the fumes/fuel in the airfilter and intake tunnel.
(If that would have been the case, the whole bike could have been torched...)
But there´s no crust on the intake rubber boots, no sign of soot on the inside walls of the airbox. There was no smoke or "poof" from the carb area.
I´ve seen carbs backfire on cars and bikes, and you get that special reversed "SCWOO-OOP" sound, and a thin sooty residue on the carbs intake.
The goo in my carb/s is somewhat greasy and oily. Not that dry charred coal-like residue. I´ve never seen anything like it. And it only smell like a carb normally does. That mechanical and gasoline whiff.
..Very weird..
Here's a really wild shot then, how's your battery and charging circuit? And where does your battery vent to? Battery acid would do that, and overcharging would lead to the battery vomitting acid.......
Like I said, a really wild shot........ :lol:
Quote from: "Bixxer Bob"Here's a really wild shot then, how's your battery and charging circuit? And where does your battery vent to? Battery acid would do that, and overcharging would lead to the battery vomitting acid.......
Like I said, a really wild shot........ :lol:
Hey Bix,
Wild it may be, but even shots in the dark are better than nothing.
However, I run a sealed gel-battery, so there is no vent...
Thanks man,
/P
when you had the carbs out last did you use anything on them to 'lubricate' the rubbers to make the boots easier to go back on ?
that would be my guess if fire is ruled out ..................something definitely attacked the rubber still looks a lot like fire in the pics though especially the grunge on #3 slide
Any smell of acetone in there? I have seen rubber do that when exposed to acetone. E-85would more likely just dry out the seals etc. Pissed any body off lately? :evil:
Quote from: "Mustang"when you had the carbs out last did you use anything on them to 'lubricate' the rubbers to make the boots easier to go back on ?
that would be my guess if fire is ruled out ..................something definitely attacked the rubber still looks a lot like fire in the pics though especially the grunge on #3 slide
Hi Mustang,
Nope, they went on dry.
-Might have used some saliva, but I brush my tooth and haven´t been on the heavy stuff for a long time now :D :D
But I think I might have a clue as to what happened.
I´m leaning more and more towards some kind of fire as You all say.
After all, -if it looks like a cat and meows like a cat...
But! (and there´s a big butt) I´m thinking in lines of:
Let´s say they
did burn.
-How "big" a fire or thermal development must it not have been to cause the rubbers to look like this?
If You would lick these rubber with a flame, how long would You have to go at it before they look like this?
And if You did, would there not be a massive smoke development?
Would these rubbers not be smelling like "holy smoke", in fact the whole bike would probably smell like shit.
-Unless the smoke was sucked into the combustion chamber and on through the exhaust pipes.
I have to move on, I have to let this go! :twisted: :twisted: :twisted:
Is there anyone here that can guide me to a "safe" and reliable way to assebly the carbs back again?
I´m hoping to get these carbs back in order after all, but obviously I did something wrong the last time I put these back together.
Is there anyway I can check the function of the carbs when they are out of the bike?
Quote from: "PompeyLad"Any smell of acetone in there? I have seen rubber do that when exposed to acetone. E-85would more likely just dry out the seals etc. Pissed any body off lately? :evil:
That is what is so strange, there is no smell of anything unusual. No acetone , no burnt rubber or soot, no nothing really.
-Actually it does not even smell of gasoline...
Quote from: "Persson"My bike has been running funny. Jerking and sputtering, uneven idle and backfires sometimes. In short, not well at all.
based on this info My theory is that the
intake valves on #3 are at zero clearance , possibly other cylinders as well . zero clearance on intakes
will cause backfiring thru the carbs .
It backfired and the fuel caught fire and everything went south from there .
once the fire started you had a needle valve stick open or melted a float which let the crankcase fill with gas
Quote from: "Mustang"Quote from: "Persson"My bike has been running funny. Jerking and sputtering, uneven idle and backfires sometimes. In short, not well at all.
based on this info My theory is that the intake valves on #3 are at zero clearance , possibly other cylinders as well . zero clearance on intakes will cause backfiring thru the carbs .
It backfired and the fuel caught fire and everything went south from there .
once the fire started you had a needle valve stick open or melted a float which let the crankcase fill with gas
That is a good theory, and I will see what I can do to find out exactly what has happened.
Some short background info on the bike:
1998 Steamer Keihin equipped, with ca 40000kms on the meter.
I bought it last year from this chap who lived roughly 500kms from me.
Went down there and found it to be in better condition than expected, so I bought it. (It was/is really in excellent condition.)
However he had not used it for quite some time, only a couple of times per year, so it needed some TLC.
On the way home it ran fine the first hour or so, but later I noticed the engine started to run a bit jerky on low revs.
Nothing bad, only annoying.
Back home I registred here and got the tip about possibly poor performing coils. So I fiddeled with that, tested the bike, fiddeled some more, and so on, but never got the engine to run smooth all over the register.
I ran out of time and it became winter, so I put her away for the season.When I got back to it this season, I noticed that all 6 of the rubber boots connecting the carbs were all dry and cracked straight through at some places.
The airfilter needed to be replaced as well.
So I replaced all those parts, filter and rubber boots and at the same time cleaned out the floatbowls, visually inspected and cleaned the carbs.
Then put it all back together again.
--> And it´s probably somewhere here that I messed things up.
It all went back nice and smooth, and I took it for a test drive.
Performance was good, started up right away just as always, but with just a hint of "pofpof" when letting back on the gashandle. But no major.
Then suddenly it started to loose power, jerking more and more, and even stalled and died on me at an intersection.
So I headed back home and put it in the garage with no time to deal with that at the time.
When I started it up later that week, it started up right away, but with a heavy cough, spluttering and sounding awful. I tried a little twist on the gashandle, but it was jammed shut.
It was at that time I took it apart and found this rubber-boot havoc...
So I agree, the valves could be tight and probably need to be checked anyways.
But when it ran fine, it ran fine..
And I haven´t put more than 100km´s since then in test-runs. Not even that even.
Here is my reflection about it all:
-My guess now is that there was never any problems with the coils in the first time.
It was those cracked rubber boots and totally that caused the bike to jerk on low revs, and I messed things up with the floater needle causing the carb/s to freeflow and fill up the crankcase.
The gasoline dissolved the silicone around the airfilter, turning it into gooey silicone-chunks that then was sucked into the carbs in some kind of halfglue form, messing upp the moving parts in the carb and gluing them shut.
At some point here there was an ignition of the gasoline in one of the carbs , and that flame torched the rubber boots turning them into...crap?
And you are most likely right Mustang, something made the engine to backfire and a tight intake valve sounds like a possible culprit.
BTW,
Who was it here on the forum that made that excellent valve tool?
Anyone knows?
:D :D :D
Well you could always experiment setting fire to the old ones just to satisfy your curiosity :wink:
Quote from: "Sin_Tiger":D :D :D
Well you could always experiment setting fire to the old ones just to satisfy your curiosity :wink:
Not bad at all!
:rock :rock
Quote from: "Persson"BTW,
Who was it here on the forum that made that excellent valve tool?
Anyone knows?
Mustang
http://www.knlcycle.com/ (http://www.knlcycle.com/)
Quote from: "rf9rider"Quote from: "Persson"BTW,
Who was it here on the forum that made that excellent valve tool?
Anyone knows?
Mustang
http://www.knlcycle.com/ (http://www.knlcycle.com/)
Haha! Of course, who else? :D :D :D
Thanx RF
...Mustang, You there?