White smoke :(

[motopsycho87]

So yeah, basically its got all the symptoms of head gasket gone. I keep boiling over, even when the water isn't hot yet. So all I'm asking is, is there any other way coolant can get into the engine? Base gasket? Water pump? Anything common?!

Thanks! :nod:

 

[sr5bidder]

the coolant does not go beyond the cylinder so it is either the head gasket or the cylinder has a crack

 

[motopsycho87]

Is there much of a history of cylinders cracking on these bikes or are you just throwing that suggestion in for the sake of it?

Any recommendations on better ways to get the head to seal?

 

[EYY]

The head gasket sounds like the problem. The only thing you can really do is take it apart and find out. At the most you may need to machine the head to make it flat again, but only if it had warped when being overheated.

 

[motopsycho87]

I machined it flat when I did the top end last year... :(

 

[EYY]

You could try replacing the head gasket at first, but if it does it again i'd be looking at re surfacing it. It only takes 20 minutes to remove the whole top end, so it shouldnt be too much of a hassle. Plus, gaskets are relatively cheap :) Did you take much metal off when you machined it?

 

[motopsycho87]

Enough to ensure a completely flat surface. I've bought some VHT Copper gasket goo, so I will try a thin layer of that with the head gasket 1st, unless when I measure it I find it to be warped.

 

[sr5bidder]

Is there much of a history of cylinders cracking on these bikes or are you just throwing that suggestion in for the sake of it?

Any recommendations on better ways to get the head to seal?

just throwing it out ther you know.....

there are two areas that need to be purged when filling the kdx up with coolant one is on the top of the cylinder and the other is on top of the left radiator

if you are blowing coolant out before it is warmed up I would take the cylinder off as well and give it a good looking over

 

[sr5bidder]

Enough to ensure a completely flat surface. I've bought some VHT Copper gasket goo, so I will try a thin layer of that with the head gasket 1st, unless when I measure it I find it to be warped.

I reused my head gasket and spray it with the permetex copper spray- a -gasket stuff. I have only seen the bike boil one time while riding slowly through the PA black quicksand muck and it had no ill effects on the head

 

[mudpack]

the coolant does not go beyond the cylinder so it is either the head gasket or the cylinder has a crack

Actually, the water pump is located on the crankcase, and is driven by the crankshaft. It's possible that coolant could be leaking into the crankcase, but if this were to happen, there would have to be bad CS seals as well as a bad WP seal.
Probably the head gasket, since these bikes don't seem to have a proclivity to crack cylinders.

 

[sr5bidder]

Actually, the water pump is located on the crankcase, and is driven by the crankshaft. It's possible that coolant could be leaking into the crankcase, but if this were to happen, there would have to be bad CS seals as well as a bad WP seal.
Probably the head gasket, since these bikes don't seem to have a proclivity to crack cylinders.

too fancy of wording my head hurts :cool:

 

[motopsycho87]

Head gasket had gone :) got the copper gasket goo and cleaned up and annealed an old gasket I had laying around at work in one of the 1300'C ovens (at 850'C). Head and barrel have less than 0.01mm deformation so all is good :).

 

[sr5bidder]

so are you back ring ding ding'n ?

I am going to durhamtown for riding and camping if the weather warms up a little on the 25th

 

[motopsycho87]

Not yet, awaiting the goo to arrive...

 

[sr5bidder]

I am not sure about the goo.. who recomended it to you?

 

[EYY]

Personally i would just try a new head gasket if the surface of the cylinder and head is within spec

 

[motopsycho87]

I had a good hunt round the net, it is a copper based gasketing compound, basically the same as the spray stuff everyone uses but rated at a higher temperature, I don't have the information on it with me atm.

Anyway, it looked to me as though the old gaskets jointing compound (the black stuff) was no good as most of it flaked off, hence cleaning, annealing and then getting some other stuff on it.

 

[sr5bidder]

I dont think new ones come with "black stuff".. I have been through alot of 2 stroke motors in the past couple years and got new gaskets for most except the kdx and none had anything but pure copper. but come to think of it every other 2 stroke was air cooled so I am probably wrong.....

Now the warrior and the xt 350 I remember had the graphite or whatever it was

 

[motopsycho87]

All is fine now, no bubbling of the cooling system :)