Checking for cracks.

[mikeB]

Hey guys, i just did a top end on my KX250F and it didnt smoke before it was taken apart. Now that its all said and done the bike smokes like a chimney and reeks of coolant.. and still have some oil weeping from the head gasket on the exhaust side of the motor..

* ALL GASKETS ARE NEW. NONE WERE REUSED*

im guessing i have a cracked head or jug or even head gasket since the fluid is being burned..

Again i took the bike apart and put it back together and torqued the 4 head studs to 104 IN LBS and im still having problems..

Anyone have pointers on how to try and solve this problem?!? and does the 104 inch pounds sound right for head studs/!?

Any help would be greatly appritiated

[chucked]

That torque seems awful low. Are you sure this was for the studs and not a small bolt that might be going through the head on the other side of the cam chain.

[bustedknuckle]

read your service book.or get one .

[jesseweaver]

Originally posted by mikeB
Hey guys, i just did a top end on my KX250F and it didnt smoke before it was taken apart. Now that its all said and done the bike smokes like a chimney and reeks of coolant.. and still have some oil weeping from the head gasket on the exhaust side of the motor..

* ALL GASKETS ARE NEW. NONE WERE REUSED*

im guessing i have a cracked head or jug or even head gasket since the fluid is being burned..

Again i took the bike apart and put it back together and torqued the 4 head studs to 104 IN LBS and im still having problems..

Anyone have pointers on how to try and solve this problem?!? and does the 104 inch pounds sound right for head studs/!?

Any help would be greatly appritiated

do we really need to know what your mom drives?

[400exrider707]

Lets see here...

It didn't burn coolant before...

You used new headgasket and the same head that didnt burn coolant before...

You have no clue what the torque spec is clearly...

Now it burns coolant...

I'd say you didn't torque anything properly. Buy a new headgasket, get the correct specs and have another crack at it.

[mikeB]

104 in lbs is what the dealer told me for the head studs..

[400exrider707]

Originally posted by mikeB
104 in lbs is what the dealer told me for the head studs..

104in lbs just cant be right... Maybe for the valve cover or something, but not the headstuds themselves.

Think about that... 104/12 ~ 8.6 ft/lbs.

Do you think a headstud should be torqued to less than 10 ft lbs?

There is no way that is right. Maybe check on thumpertalk where there are more bike guys. Most headstuds I've done on quads are in the low 30 ft-lb range, and I usually go a few over that.

[mikeB]

alright thanks for the helpp!

[Exrider434]

Originally posted by mikeB
104 in lbs is what the dealer told me for the head studs..

from my experience,the dealers know less than what a book will tell you. Pick up a clymer's manual and you will have every bit of info you need to know!

[SRH]

yamaha has a method to torquing the head, this amount of ft pds then back it off torqued to such and such a ft pd then turned 90 degrees

[400exrider707]

Originally posted by SRH
yamaha has a method to torquing the head, this amount of ft pds then back it off torqued to such and such a ft pd then turned 90 degrees

That almost sounds like a TTY bolt, are they not reusable? Is it a bolt or a stud?

[chucked]

Originally posted by 400exrider707
That almost sounds like a TTY bolt, are they not reusable? Is it a bolt or a stud?

I doubt the torque is so high it cannot be reused. The torque for his head is probably 20-25 ft/lbs

[250x_kyle]

Originally posted by jesseweaver
do we really need to know what your mom drives?

have you ever followed the quote in your signature? you may not agree with what he has in his signature but it was no help to any of his questions

on the other hand, i would look into getting a repair manual if you dont have one. torque specs dont sound right to me.

[400exrider707]

Originally posted by chucked
I doubt the torque is so high it cannot be reused. The torque for his head is probably 20-25 ft/lbs

I doubt that as well, but that's usually where you see torque angle methods being used, as opposed to a torque number. That's why they're called torque-to-yield (tty) bolts. They're designed to be torqued to the point that they actually stretch, thus, not reusable. I've never really seen this in an ATV application however since the torque numbers are usually pretty low like you said.

[chucked]

I know I rebuild diesel engines time to time. Ive done some where you torque it to 250 ft lbs then end up putting another 270 degrees on it. Gotta strap it to something big and use a huge breaker bar.

[Tommy Warren]

Originally posted by chucked
I know I rebuild diesel engines time to time. Ive done some where you torque it to 250 ft lbs then end up putting another 270 degrees on it. Gotta strap it to something big and use a huge breaker bar.

he's right just put a huge breaker bar on it and giver all you got....should stop any leaks:devil:

[Smoker]

How did the dowels look? (hollow tubes that go in between cylinder and head) If they were chewed up it may cause the head to not seat properly, or if you didn't put them back in it would cause leaking of things. Just an idea.

[chucked]

Originally posted by Tommy Warren
he's right just put a huge breaker bar on it and giver all you got....should stop any leaks:devil:

Yes!! Just torque down till you hear something crack then back off 90 degrees.