Engine Crankcase full of fluid

[Crackers61]

Hi All,

Wondering if anyone has come across this issue before.
I went to drain my oil in my 78 special, and to my surprise i had at least 5 litres of fluid. It seemed to be a mixture of both oil and petrol.
The bike has been sitting around for about 6-9 months prior and when starting for the first time it ran like a dog.

I think what has happened is the petrol from the tank has slowly drained via the bores into the crankcase. I didn't think this was possible?

The compression is good 100 psi left hand clyinder and 120 psi right hand clyinder.

Has anyone come across this before?

I'm interested to know

Regards
Crackers















it

 

[Paulrxs650]

Hi,

Sounds like the petcock was either left on or has failed but you also want to check your float heights and flat valves for correct operation.

The petrol is being allowed to enter the bowls, fill them up and overflow into the bore, then seep past the rings and into the cases.

Should be a relatively easy fix

 

[grizld1]

Hi Crackers! See that little box labeled "Forum Search" toward the top of the page? Or the button marked "Tech" in the line above it? Use either of those to discover how very many times your question has been asked and answered.

In the meantime, here's a useful definition for ya.
Vacuum Petcock: A device engineered in Hell to Satan's specifications, with a primary function of driving owners of motorcycles to acts of rage and despair conducing to their eternal perdition, through its secondary function of filling crankcases up with fuel.

 

[TwoManyXS1Bs]

...Wondering if anyone has come across this issue before.
Has anyone come across this before?

Here's one: http://www.xs650.com/forum/showthread.php?t=39767

 

[DC Cycle Works]

On a side note, that compression should probably be addressed at some point that's a little on the low side and a difference of 20% between the two

 

[Paulrxs650]

Indeed, just make sure that when you're performing the compression test, you are doing it with a wide open throttle

 

[Crackers61]

Hi All,

Thanks for the input. I did think about searching the forums, however thought it was such an odd fault that it might just only be a one of!

Thanks to all for the input.

Regards
Crackers.

 

[gggGary]

I drained the crank 3 times on ONE bike last year, damned vacuum petcocks anyways. I swear I will win but I have been smelling a hint of gas in the shed again....

 

[gggGary]

Most barn bikes have at least some gas in the crank vacuum OR manual petcocks when I find them. Better than water in the crank!

 

[lakeview]

Hi Crackers: Your experience with the search feature echoes mine. Early in my dalliance with XS 650's I pulled a side cover off and saw that the kick start spring anchor had been sheared off plus someone had glued it back on and it was in the bottom of the case. I thought this was world shaking and novel so I started a thread about what to do with it and was gently advised to use the search function (I guess it was not all that uncommon!)
Of course with a few key strokes the info was there.

Since then the search box is my primary resource and most of the time has provided the answers I am looking for.

 

[Crackers61]

Hi All,

Once again thanks for all the replies. In the past i have used the search forums before on a number of other un related issues.

I'd also like to add isn't great that so many like minded individuals still like to fuss over these great old bikes, which also helps other like minded maintain and enjoy these old machines and creates a really great web site like this one!

Oh and by the way while i have been working on my 78 special i also noticed a smell of petrol (gas) in my shed (the tank was siting out of the way on my work bench not on the bike). I'm going to replace the petrol tap on my tank, get rid of the vacuum type.

Regards
Crackers