Cylinder Head Studs

[bigmac103]

Had a few problems recently, oil leaks and that. When I solved one major oil leak a new leak would appear. This time it was the head, both front right hand and left hand oil wells burst their gaskets. So head off and to my horror the cylinder studs unscrewed by hand. The engine wasn't put together very well, I think the guy who did it must of thought a Torque Wrench was a buxom lady who spoke a lot!!!!

Anyway, the studs are oil wells and full of oil so without removing the barrels can I drain the the oil from the stud wells, locktight and torque the studs? if so how? and what is the correct method and torque (lbs) for the studs?

Here's a couple of pics if it helps?

[Pasc]

If the studs can be removed by hand couldn't you remove them and use a compressed air gun with a biece of tube on the business end poked down the holes and blast the oil out ?

[Pigford]

I believe the studs are set by length protruding (not torque setting)

[bigmac103]

Mr P ok, but are they thread locked? How long must they be? Can't find this info in the manual Air blast is a good idea, I'll try that

[Al]

Its a proper faff to take the barrels off but as i was repeatedly told "there'll never be a better time"
Did you manage to get the head off without disturbing the base gasket?
If youv'e been blowing gaskets and seals all over the place the base gasket may already be on its way. Be a shame to put it back together only to find this out later. Specially as you're ordering gaskets for else where.

Anyway, what i was going to ask was whether you have any crankcase compression?
Is there any signs of the head gasket leaking anywhere else apart from the insert copper 'O' rings?
Maximum oil pressure is about 20 psi cold on a good engine and normal hot running pressure is only about 4 psi or so therefore these components are not stressed.
Cylinder compression leaking across the gasket may cause this but it will show up in other areas' as well.


Oil gets dirty very quickly
Oil smoke or vapour from the breather
Cam end caps weeping or popping out
Oil consumption high

Any signs of combustion products in the oil galleries of the head where they meet these oil seals?

AL

[zed1015]

Once you've got the oil out loctite the stud and torque to 25lbs. There's a shoulder on the stud at the crankcase end so it will only go in so far and sets the height. Use a 1/4in ballbearing inside a std headnut to tighten the stud, this stops the nut locking onto the stud when you remove it and is easier than using two nuts locked together. ( This is how the factory do it, See the small dimple on top of each stud where the bearing sat ?)

[bigmac103]

Oil consumption was high but I believe that to be because of the leak I had from the crank case. I cured that to then get two leaks from the head. The problem for me is I haven't got the tool for the piston rings, postage costs to Spain and all that! so I was careful not to disturb the base gasket. Bearing in mind this was only put together 2 months ago and done about 1500 miles. The oil did get black quick!

I was going to replace the valve seals, head gasket and thread lock studs to 25 lbs tq as suggested (thanks for that z1015). What else should I do?

[BShaw]

head gasket in for sale section........ Cometic........way to go. Couldn't copy link sorry.

use plastic or tin cans cut down and jubilee clips for rings

[Garn 1]

BigMac, did all the studs come out when you undid the head nuts, or just a few. If it is only a few and you have recently done the rings [2 months ago], I would simply remove head and replace head gasket and do seals etc. screw the bolts in, with a stud extractor. I don't beleive these stud holes are blind, (I'll check tomorrow) hence, the oil compressing in the bottom of the hole won't be an issue. Use new copper washers on the four outside nuts and tension up. On any head that I've had trouble with, I would go up to 30 Ft-lbs on a cold head.

If I misread that, about the new rings... than now is a chance to do them, easy job! New base gasket and lge o-rings.
RegardZ

[bigmac103]

Thanks Garn 1 I believe the pistons and rings were renewed before I got the bike, and they do look ok. So I don't think there's a need to take the block off this time. I've just replaced the valve seals and they did look suspect so I'm glad I've done them. I'll have a good look at the studs, clean them up and do as already suggested.

Baz I got a complete gasket set a while ago thanks, otherwise I might of had that gasket.

The head is coked up more than I would of expected but I'm not sure if this is just the same coke sitting there before the pistons were done and it wasn't cleaned off!

[Al]

bigmac103
PostPosted: Fri Aug 28, 2009 7:12 am Post subject:
Oil consumption was high but I believe that to be because of the leak I had from the crank case. I cured that to then get two leaks from the head. The problem for me is I haven't got the tool for the piston rings, postage costs to Spain and all that!

You could try; Piggy's Patented Polyethylene (PET) Pintsize Plastic Potnoodle Pot Pistonring Placement Promoter if you dont have the proper tool.


AL

[debben1]

the recommended torque settings for the heavy duty cylinder studs is just 19.5ft.lbs, I would not recommend going above this, check the studs have not stretched as this is common, once the studs stretch the cylinder head nuts can bottom out on top of the stud and this may be why the stud has come loose (as you undo the nut which has botttomed out on to the stud it works like a bolt and unscrews the stud) Regards, Steve

[bigmac103]

Thanks for that Steve. I've managed to put it all back together and discovered another couple of problems. First there's a helicoil come loose on the camsahft bolt and worst of all the cam chain slips when I turn the engine anti-clockwise, clockwise is fine. What am I doing wrong, four times I've reset the timing and pulled the cam chain taut. Getting a little dismayed to say the least

[hillbilly]

are you sure the chain is on the bottom sprocket on the crankshaft,sometimes they come off when you dismantle them,you pull them tight thinking there on but there sat to the side. also do you tention the cam chain with the tentioner,before you reverse the engine.

[bigmac103]

Makes sense hillbilly, what are you supposed to do with the tensioner? I think this is the root of my problem