White smoke from Crankcase Breather?

[e_sloan]

Got my bike back from the shock for carb problems and when I get home (20 miles) I have a large puddle of oil under the bike. I search around trying to find the source to no avail. I take the air filter off and start it up and there is heavy white smoke coming out of the crankcase breather tube. Enough so there is a puddle of oil in my airbox and my filter needs a serious cleaning.

Any ideas?

Its an 82 XJ550

[Dragonrider]

Sounds like there is fuel in your oil....maybe your carbs were leaking past the floats...that can make it's way to the crankcase.

The oil will foam and come out all kinds of places. Don't run it that way...change it now.

[e_sloan]

So by the sounds of it they didn't balance the floats? Hmm, I will have to look into that.

If gas is getting in the oil it will cause all of the oil to get to thin and come out of the crankcase?

[strom]

Check the oil level. Too much oil in there? I think it wouldn't come out there if oil was too thin, just too much of it.


LP

[Dragonrider]

(snip)
I think it wouldn't come out there if oil was too thin, just too much of it.
(endsnip)

Trust me, it will. If there is gas in the oil, it will foam up and come out anywhere it can. (from the been there and done that too many times on air-cooled in-line 4's catagory)

[dbyers]

I had the same issue with smoking like crazy when I put in too much oil. Make sure when doing an oil change that you have someone steady the bike as level as possible when checking the oil level on the site glass. I with out thinking checked the oil level while it was on the kickstand and added oil to what I thought was the full level. It was too much and oil blew all into the breather box and it smoked out the back. That may not be the problem but it's something too look at that will cause smoking....

[strom]

Originally posted by Dragonrider
(snip)
I think it wouldn't come out there if oil was too thin, just too much of it.
(endsnip)

Trust me, it will. If there is gas in the oil, it will foam up and come out anywhere it can. (from the been there and done that too many times on air-cooled in-line 4's catagory)

OK.... I guess that can happen in an old can... but this is the ELEVEN! :P (not a valk.... )

OK, better stop writing coz I aint feelin like runnin....
When I had gas in the oil, there was just lotsa smoking out back, but that was due to the worn piston rings.

LP

PS: Is it oil or white goo? I had some white goo there, but it was there on all the bikes I had... except two.... (MZ 250 ETZ and K&N equipped moto guzzi).

[e_sloan]

I checked the compression across all 4 and it is all around 120, so my worries of a burnt ring are relieved. Now my plans for the long weekend are going to be trying to figure out where the gas is getting into the oil and where the oil is leaking from.

First I drained the gas contaminated oil, put in a new filter and new oil. I am then going to take the carb off in the morning and check the floats. It that doesn't solve it I am getting it towed back to the garage so they can have a piece of my mind.

[e_sloan]

WOW I just finished draining the oil, almost 3 liters and very low visoscity. There was alot of gas in there.

[ratbyk]

Fuel Leaking

Once you have the carbs off and float bowls removed, turn the bank of carbs upside down. Try blowing into the fuel inlet line to each pair of carbs. (1-2 then 3-4). The weight of the inverted floats should seal the valve. If you can move any air then that needle and seat is not sealing/cutting off the fuel flow. You will have found your problem. First check for dirt in the seat of the N/S. Use reading glasses or a magnifying glass. You are looking for dirt, even a hair can cause the N/S not to seat.
If no dirt found but needle will not seal try using valve (fine) lapping compound to get the needle to seat. You may have to purchase new N/S but lapping usually solves the problem.
If the N/S appear to be doing there job check the floats for leaks. Remove each 1 at a time and give it a small shake to see if it is leaking fuel and loosing it's buoyancy. Could also immerse the float in warm/hot water and look for bubbles as the expanding air within comes out the leak/hole. This will also identify exactly where the leak is. These leaks can be soldered over in most cases.
If you find dirt in the N/S area certainly install in-line fuel filters in the system. In fact install a pair of in-line filters anyway. Good insurance.
Also check to make sure your petcocks are not leaking while in the run or reserve position. (on a standard) (on a special with octopus) fuel should flow from the petcock but not past the octupi downstream from the diaphragm.
Have fun. If you still have the original fuel lines on I would highly recommend that you replace all of them. 25 year old lines can start to break down inside and have small pieces of rubber flake off causing this flooding problem.
Ken/Sooke
78E Ratbyk
82 FT500 "lilRat"

[e_sloan]

I ripped the carbs off again, the valves are definately sealing, and the floats didn't have leaks.

Took her for a 10 minute hard ride had plenty of power, sounded a little loud from the exhaust. When I got back I checked the plugs. They looked brand new, just a little tan colour to them.

But, I opened up the oil and gave it a sniff, sure enough there is gas in there again, oil level has risen significantly as well.

If its not the carbs leaking, what else can it be?

[chevy45412001]

leaking

there is only one place gas goes into motor,thats through the fuel supply line. into the carb,so if you still are getting gas i would suspect the part that keeps gas from pouring into the carbs. Octy my guess.My n/s were fine but the gas would flow like a @itch into my motor overnight.turned out to be the five hole gasket in the petcock.replaced with new no prob sence.

[Dragonrider]

It's the carbs for sure...even if your octopus or petcocks aren't shutting off, the floats/valves should still stop the gas. If they aren't sealing though, it can make a carb problem worse by allowing gas to flow while you are parked. If you have a special, make sure the octupus is shutting off when no vacuum is applied. I had trouble with a rebuild kit...it was sized incorrectly and it leaked even with brand new parts...but the unit is available new for about $40...just hunt around the 'net a bit.

But the carbs are the real problem...you must fix those!

My guess would be a float that is too heavy, sinking and rendering your float level incorrect....or a bent float pin or such making one stick or bind

Take the carbs off, put them in a vice, and hook gas up to them.

A non-sealing or sunk float will show up fast...gas running out the carb...

Then check the float levels by hooking a clear hose to the carb bowl drain and holding it up beside the bowl. Adjust as needed.

Good luck!

[uk1.1s]

Had the same thing....

.....beginning of this year.

Petcock repair kit and new float valves cured it (tackled at the same time)....was running through into the engine - and had exactly the same effect .... LOADS of oil/petrol in the sump.

Danger of running like this I can think of quickly are:

1. Potential warm fuel fumes from the sump finding an ignition source.

2. Such high volumes of "oil" can over-pressurise the gaskets and give you more pain in the form of a new head and/or base gasket replacement. Although the foaming Dan describes may alleviate this.

3. Thinned oil / fuel mix is not as lubricating so wear goes up greatly.

4. I think (?) fuel is corrosive to bearings in some situations....could be wrong here.... but I drained quickly after discovering high apparent oil levels as I didn't want the petrol (gas) to sit in the sump with the main bearings for too long.

Try Ken Talbots quick fix for the petcock seal (I think it was you Ken) - take apart the tap and turn over the petcock seal (the flat circle with three - (or four) holes punched in it). The other side is a mirror image and should do the job as well. If the float valves are doing their job as you suspect then this should sort it.

My thoughts are that you need both the taps AND float valves to be misbehaving for this fault to happen.... but I'm happy to be proved wrong.

[rover]

My special without the octopus (removed it cause it did not work anyhow) will leak some fuel if parked on the side stand with the floats properly adjusted. With no octopus or with one that don't shut off, the petcocks MUST be closed manually or some fuel will spill due to the angle of the carbs when on the side stand, but if a lot of gas gets in the oil like you say, the float valves ARE leaking or set way too high, AND the shut off (petcocks on the standard, octopus on the special) are not closing the fuel supply.
If you have a standard, there is no way to shut off the fuel other than the built-in vacuum operated shut-off. There is no off position on the standard petcocks, only on the special.