Head gasket problems

[boyd]

Hello, I recently had some problems losing power under acceleration, I think I've traced it back to a leaking head gasket, I took the head off to see there was no gasket at all. I put a gasket in , copper type, and reassembled but it is still leaking. Is it time to have the head machined or is there an easier, hopefully cheaper, option? Also noticed the valve lifters were just loosely threaded onto the rods, should they be lock nutted, if that's a word? Any help much appreciated. Boyd

[Janet]

When you've adjusted the tappets you should lock the nuts or they will just slacken off again.

See Page 15 of the owner's manual. http://www.archives.jampot.dk/Book/Owne ... Manual.pdf

[Rob Harknett]

ooopss you caught the tappets just in time, you will need at least one thin spanner to get 2 spanners close together on the lock nuts. Did you scrape all the old muck off the head and barrel, If you did that's only half the job. Or more problems if you srored up the surface. Once clean I often grind the head on. After some time it will soon show up low points, perhaps even obvious area for gasses to escape. So keep grinding until both surfaces match. Just grinding the head may not help. It takes time, but so does taking the head to have it ground. I have even ground these joints and not used a gasket. Its no different from grinding valve seats, they don't get a gasket to seal the seats.

[Ozmadman]

I got the impression he was talking about the actual rocker arms (valve lifters) and not the pushrods?? As for he head I had a nightmare trying to get a copper gasket including a new one to seal and finally gave up and went for a composite. Didn't think you could grind the head against the barrel because of the lip on the barrel which stops the two surfaces from mating?? And there's that small oil feed hole which is prone to leaking. so I would clean it up, flat the head with some fine emery on a flat surface( not too much as you don't want to increase the space between faces as you want a good squash on the gasket) and use a good composite gasket obtainable from here. Torque it down to 35lbsft( the 4 main studs only) and just nip up the thin bolt sensibly with a spanner, don't over tighten that one it will strip as I know from experience. Run it for about 5/10minutes at fast tick over so it's hot, leave it overnight to cool down then re-torque it again. Then go for a gentle run keeping the revs down, leave it overnight to cool down again and then do a final re-torque. I did this and I know it's a pain, rocker cover, tank etc. on and off but I have had no problems as yet.
Paul

[Janet]

I got the impression he was talking about the actual rocker arms (valve lifters) and not the pushrods?? Paul

No doubt you're right. It was his use of the word 'rod' that threw me.

[boyd]

Thanks for getting back, I will try a composite gasket and the emery paper. Is the gasket listed in the lightweight section of the spares list, the composite one? The last one came from a gasket kit. Is there
Any kind of silicone or gasket compound that might help?
Also it was just the valve lifters I meant, Should they be loose?
Thanks

[SPRIDDLER]

the valve lifters I meant, Should they be loose?
Thanks

Do you mean the long vertical tubes (pushrods) or the snail shaped pieces (valve lifters) at the top which the pushrods push?
I, as Janet did, assumed you mean the long vertical tubes (pushrods) .

[Ozmadman]

Thanks for getting back, I will try a composite gasket and the emery paper. Is the gasket listed in the lightweight section of the spares list, the composite one? The last one came from a gasket kit. Is there Any kind of silicone or gasket compound that might help?
Also it was just the valve lifters I meant, Should they be loose?
Thanks

042840 is the part number of the gasket available here in the spares section, you don't need to use any sealer or compound, put it on dry. To clarify.. The rocker arms or pushrods?? Either way ( the nuts on them) should NOT be loose. The pushrods clearance is set when the engine is warm and on TDC on the compression stroke( both valves closed)so you can spin them freely but with no real up and down play. The rocker arms should be tight on the spindles, so whilst the head is off check the tightness of the nuts at both ends of each rocker shaft.
Paul

[boyd]

Ok it's the push rods, sorry for confusion, there is nylock nuts on them that are finger tight at best, I can see two thinner nuts below them that I presume are the lock nuts. Thanks again, I'll order the gasket now.

[Ozmadman]

Ok it's the push rods, sorry for confusion, there is nylock nuts on them that are finger tight at best, I can see two thinner nuts below them that I presume are the lock nuts. Thanks again, I'll order the gasket now.

Nyloc nuts?? You should have a cup at the top to take the end of the rocker arm which has a hexagon on it maybe you are mistaking that for a nyloc nut???, this is threaded into the push rod and then the two nuts are tightened up against the pushrod and each other to lock the threaded cup once you have made the adjustment. Confused as to what the Nyloc nuts are doing?!
Paul