drained the oil on my k75s today brown sludge is what came out any ideas?thanks in advance guys

What colour is it, is it milky, it could be water? Check to see if your water level is down. When was the last oil change? Is the bike new to you?
Regards Martin.

Brown oil DEFO water contamination.Run a compression test to identify blown head gasket ect.Oil/water pump maybe suspect also.This engine will need  SERIOUS Flushing 

Whats the history of the engine? Last oil change? had the bike long? any leaks of coolant? condensation inside engine, etc etc

Need to know more.

There is a weep hole on the water/oil pump on the front of the engine. 

Is it blocked?  If so, coolant getting past the water pump shaft seal will be able to get into the oil past the oil pump shaft seal.  If the hole is plugged with dirt, etc, when you clear it, I would expect coolant to come out.  That will tell you that you need to rebuild the pump.

When you start the bike do you ride it till the engine gets hot? Do you only do short journeys that never get the oil up to temperature? Do you ever start the bike and not ride it?
All of these things can destroy an engine.

MartinW wrote:What colour is it, is it milky, it could be water?

The description seems chocolate milky or unbaked fudgy.

hi guys
the bike is new to me it lay covered for 12 years I got it running before I stripped it down to build a cafe racer.the water pump leakage hole is clear the oil was like milk chocolate.I have stripped the waterpump .but what is worrying me is there was water in number 3 cylinder when i was trying to get the bike running so im thinking the head gasket is away.when i got the bike it was just an engine in a frame i put water in it then ran it for about 15mins .so i drained the oil then noticed the crud i dont know whether to replace the engine yet i ordered a gasket so i will check the head anyway the engine has only done 16k miles.

I think that removing the head is the right way to go - whether the stuff in the cylinder is coolant from a leaky gasket (or worse) or just rainwater that has found its way in during storage.
It is possible to reuse head gaskets, so take care removing it just in case its okay.

cheers
i have a gasket on the way anyway and i have a pump rebuild kit but the pump now seems a bit stiff i might look for a replacement.if there is no joy with the head I will source a replacement engine.yet when i checked the compression 1 and 2 had 150 and three has 210.i did oil the cyclinders to unstick them when i got the bike but maybe the high compression and the fact that i found water in number 3 point to a gasket failure

Don't abandon the engine just because of crud, this stored-for-a-long-time mystery engine ended up running just fine with good compression - and the head gasket was reused too:


And this sludge that was in it takes some beating:

if i find a crack or damage then i will consider an engine i put one in my st1300 this year as it was cheaper than honda gaskets.im hoping it will just be the gasket

If the rebuilt pump is a bit stiff, chances are you've driven the big gear hard up against the housing. Give the nose a sharp rap with a hammer and then try turning it again.

thanks will do

Most definitely water contamination either from a bad pump or head gasket. Check the coolant for oil and a leakdown test to check for head gasket damage.

unfortunately the engine has no water attached I had stripped it all down for painting when i dropped the oil and went to change the pump kit as it had a leak from the right hand side area of the cover high up.but during my getting it running process i blew out the cylinders with air and number 3 had water in it.thus suspecting the gasket.before i put the water in and got the bike running the oil had been old but black when i removed it the colour was brown it only ran up and down the carpark too

If there is water in one cylinder then the head needs to come off.

If it was sitting and leaking at an injector O ring water can enter a cylinder through an open or badly seated valve.

so took head off and all appears good so maybe the pump is the cause I will fit a new kit in the pump and a new head gasket and take it from there.thanks for your help guys
dont know how to post pictures or i would show you