Crank Case Gasses

While trying to sync the carbs on my XJ, I noticed that there is a considerable amount of gas coming from the crank case vent. Is this normal? There's enough coming out that it's a visible little cloud.

I imagine it means I'm running way to rich?

 

Are you using a box fan to keep the motor from overheating?
Recent oil change?
Leaky carbs?

If you are running "way too rich" your plugs would be black.
What are you using to sync the carbs?

 

Hey TIMEtoRIDE. I am using a box fan. oil change last year, with only a few miles logged since then, though it did sit for a while. I rebuilt my carbs. When you say leaky, what do you mean? Leaky in what way?

 

Forgot to answer your carb synching question. I'm using a single vaccuum guage, per RickCoMatic's post on synching carbs the old school way.

 

There's a chance its actually steam.
While I was syncing my bike I had water coming out of the drain holes of the Silencers.
A generous amount, to ... I might add.

At first I thought it was oil or fuel ...
But, after picking it up with paper towel and investigating ... water!

I had a full tank of Regular Winter Gas with 12% Ethanol.
I'm sure that condensation from the Exhaust was excessive while the Bike was running Lean.

 

Leaky = flooding = gas in the crankcase = gas vapor steam out the vent, and diluted oil, possibly ruining rod bearings and piston skirts.

If it bothers you, try fresh oil. (and we're not turning this into an oil thread!)

 

I think what you are seeing is perfectly normal. That is what the crankcase breather does. You are just seeing the crankcase "breathing". That vapor gets recirculated through the carbs for another burn.

 

crackcase pressure - the reason the breather is there - is typically cuased by blowby past the rings. Normal until you get to much of it.

 

Great feed back guys. I have some more homework to do, but now have some info to run with.

I know or a fact that I should check and set my float levels, and did a tweak today on carb #4, when I noticed fuel leaking out the intake side when the fuel was turned on.... meaning leaky.... flooding. This could explain the burn off. I should definitely change my oil, this being the case. To remedy this, I adjusted the float, but I have no idea at this point if it, or any of the other three are set correctly.

As for the venting being normal... this I know... but mac11 hit the nail on the head... "normal until you get too much of it". Just how much is too much?

I'm going to venture into checking and setting my float levels. Only problem is, my drain screws are rusted, frozen in place, and most have screwed-up heads, making things even worse.

 

+1

 

There is a how to thread on this exact subject.
One thing after another on these carbs.
:roll:

 

Most bikes have crank case pressure. I have seen a great reduction in pressure after running several hundred miles after the bike has been in storage. Fix those carbs and put some miles on with the right oil in and it might get better. Don't add any thing like Lucas or Sea Foam these could cause clutch issues. Good luck