water pump seal vs head gasket failure

[neeeel]

if u saw my previous post you will know i have got water leaking into my crank case, Im hoping its the water pump seal, but are there any other signs that would tell me it was the head gasket? will the bike still start if the head gasket fails? any wierd noises happen when the head gasket goes? or just a loss of power?
thanks
neil

[cagiva gezzer]

Tell us what bike and we *might* be able to help.
____________________
"because one stroke isnt enough and four strokes waste two"

[neeeel]

J reg tzr 125 2rk
ta

[flat spot]

OK, there's a possibility it's 1 or both problems causing your issues, but not for the reason you think.

2 strokes are not built the same as four strokes. On a 2st, the gearbox and its oil are seperate to where the crankshaft sits. Basically the crankshaft, piston and rod are in their own sealed part of the engine.

Lets say your head gasket is leaking between a water channel and the cylinder and overnight it's going into the cylinder. Because it's seperate to the gearbox, it can't mix with the gearbox oil which is your problem. If it would start the next day, it would just be spat out of the exhaust.

A sign that it is leaking between the channel and cylinder is the reservior cap for your water can be blown off. This is due to the fact the pressure escaping from the cylinder when running is leaking through the failed gasket and pressurising the water system.

Now then, I don't know your bike engine, but there is a place where your gearbox oil and water system do meet. On the end of your crankshaft there will be a gear. This is spinning in the gearbox oil (although it's not part of the gearbox itself it's just being lubricated by the same oil). I assume it will be driving the water pump impeller.

So, the gear in the oil is turning another gear on the end of a small shaft which goes through a seal. On the other end of the small shaft is the impeller which is in water. This is obviously spinning very fast and pushing the water around your engine so it's getting cooled.

So if this seal or shaft are worn water will escape from the water system into the gearbox oil.
But, if the head gasket has gone and the water system is being pressurised it is pushing the water past what could be a good seal.

Here's the solution. Buy a complete gasket set, water pump seal and impeller shaft and impeller shaft bearing. Change the head gasket and torque the bolts down to the specific requirements. You may have to buy or borrow a torque wrench. I'm sure there will be a haynes manual for your bike. Buy this as well.
Change the shaft, seal and bearing at the same time and I'm quite confident your mayonaise gearbox oil problem will be solved.

Any questions please feel free to ask.



Right then off to Tesco before the hoards.