XJ 650 RJ Seca '82 - Rounded cyclinder head nut in recess - removal?

This thing won't shift - see pics. I've knocked it down at the back to try and lever it open square at the front. It raised very slightly at the front stud part (but no thread came up), then the back stud came out completely, and I can't get it back in(?)

Can't remember when I've had something that's tried my patience so much (and I've had a lot with this bike - see my thread history...)

Could it be that the head is warped, and that is making it so difficult to remove?

Give me strength!
Regs.

 

put the nut back on those studs enough to protect the threads. Then lift the head as far as you can without forcing it. Now slide a thin wooden stick in the gap.
get it as close to the stud as you can, 25mm would be great. Now push down on the head and use the stick as a pivot point. While pushing down, crushing the stick, tap the nut with a steel hammer.

 

Hi Pollock
Thank You for your reply. I am not entirely sure what you mean, but I have attached a pic prepped for the process you explain?
Let me know please?
Regs.

 

Just tried that method, and no joy. (haven't got the space to really HAMMER it.) Established now that the stud is 'seized/fused', in the tunnel where it protrudes down from head and fixed in by nut underneath in the top part of the bottom casing. (can steel and aluminium bond over time, or is it just corrosion?) Been spraying penetrating oil every few hours for last 24. All the area around is free including the lip at the bottom of the head, apart from the thread, which does not move.

Tried tightening two nuts together as tight as possible, to try and extract the whole stud, with the nuts, but no joy with that either (just stripped the thread a bit)

My neighbour is going to 'weld' a nut to the very bottom of the stud, (with one nut directly above, in case the bottom one gets 'rounded' during the welding process, and then we are going to try and turn the whole lot out as a 'bolt', with a socket head, and strong leverage on it.

Failing that, it's cut the whole thing off the bottom, (not easy (?) and drill upwards, and through to break the seal and release the head. (need to replace/retap a stud then?)

Unless of course, you fine chaps can think of any other alternative(s)..................?

Regards.

 

@pauldale999

Hold off on doing any more work. Your plan is sound, but there are a few tips I'd like to share before you proceede. I'll make those comments tonight when I have more time.

 

in that picture, try something like a popsicle stick (do they have popsicles in the UK?) and get it closer to the bolt. push down on the head,same side as the stick
maybe use a ratchet extension or two to get on the nut and reach where you can swing at it.
this motor might need to come out of the frame.
i wouldn't try to take the stud out of the head, the stud will just twist off and might still be stuck in the head

 

Ok Polock and k-moe. Thank-You for your input. I am not proceeding with my options until tomorrow evening anyway, (probably your mid-day?) so I'm all ears until then....
Regards.

 

I agree with Polock. Don't try to remove the stud with the head in place.
If you end up needing to drill the stud out, do it progressively.
The best option is to pull the engine and have a machine shop do the work.
If you do it yourself I'd sill pull the engine in order to get the best access to the problem.

Carefully center ounch the stud, and thread the nut back on partway. This will act as a guide for the drill.
Use a drill that is no larger than the root diameter of the stud (the smallest diameter of the threads; the "valley").
Drill slowly, squarely, use lubricant (used motor oil works well) and only drill a little at a time, lifting the drill so the chips can clear.
Ideally you do not want to drill clear the whole way to the head. What we really want is to relieve tension on the part of the stud that is in the cylinders so that the head can be popped loose. You'll do this by drilling about half the distance into the portion of the stud that's in the cylinders (measure twice and mark the drill with tape). Then give her a go at popping the head loose again.
If she comes free you will then have the remaining part of the stud sticking proud of the head so that it can be removed at a shop (I would not try that part at home unless you have prior experience).
If the head is still stuck after drilling halfway, then drill to the 3/4 mark and try again. If it's still stuck then you'll have to drill to the head deck (the part where the gasket is). I'll still recommend that a shop remove the stud from the head even though you will have drilled it most of the way out already. What you don't want is to turn an easy extraction for a shop into a real PITA job, or to have the bit off center enough so that the head needs to be reworked.

 

Thought carefully, about your advice but still tried the 'weld a nut on and use as a bolt' option to extract the stud. Got a spanner on it and a mighty good lever, did it gradually...... but stud just sheared off inside the nut. (like you said - but I had to try - it has worked before on other cylinder studs, and exhaust studs, seized in aluminium in the past)

The remaining thread (half of it protruding still), is still clean, and will take another nut enough to tighten the head down, if I need to.
Removing the engine, and splitting it etc... is not really an option for me - I don't have a garage, and live up some stairs in a small flat, with little space. (my bike is stored in one of those concertina-like, lift-over framed canvas 'Bike Home's)

The nearest bike shop, now is almost a mile away, and I can't really push the bike that far. (I don't really even want to think about the expense of an engineer, or transport)
No, - I've got to get the head off myself, if that means spray and wait, then rock and tap....spray and wait then rock and tap.....so be it
If I get the head off, I'm quite confident of drilling out/retapping if necessary and replacing the stud - I've done that a few times before. Only have to turn it upside down, and hold it down square, solid.

My neighbour wanted me to try and get some 'Stilson' wrench on the remaining stud, heat up the cylinder (tunnel) area and try turning it out then - but I don't think that will work, if the initial method would not budge it....? And like you said, if it shears off halfway inside the cylinder, it's going to be very difficult to drill it out square.

How long does it take for penetrating oil to do it's business on a (potentially) 1/2" long stud, seized in a cylinder? (that's if the oil is getting down in there?) The seam (above the cylinder/tunnel) is 'bubbling and oozing oil', when I rock it up and down.
I have got some brake fluid, and been told it works much quicker than penetrating oil, if I could administer that through a syringe or adapt an old plastic pump aerosol cleaner spray through the small gap?

That's where I'm at now, so if you have anything else to input (apart from the obvious - 'I told you so!') then let me have it!

And, a big Thank You! for everything so far!

Regards

 

Well - it's off! The cylinder head frontal lower stud was seized in the cylinder. Took about 3 days of spray.....wait a day.....knock. Came up about 2mm each time until third time just popped right off.

Sent for replacement stud which got half sheared off earlier. That screwed out with wrench with some effort.

Took advantage of it being off to clean up the piston wells, and valve heads. Removing all old gasket residue, and replacing dowels/deteriorated washers.

Got to retap two or three of the stud sockets up to 8mm inside tapped sockets (with 6mm extending out), and replace studs. (see pics)

 

Congrats on getting it off! When you get your gaskets, make sure you get from a reputable source or check them thoroughly. They're expensive and you don't want to do twice like I did. Here's my thread on the matter, start at post 14.

http://www.xjbikes.com/forums/threads/head-installation-sanity-check.69186/#post-470201

Hopefully that will save you the headache.

 

Proceeded to retap the stud housings (3). Successful with two - but one had old broken off 'tap' inside it, (found out after the fact!) and when tried to retap, edge of housing broke off!

Is there anything out there I can use to reform a new metal stud socket housing, and retap? (Metal chemical filler/Plastic Padding-type stuff?)
The stuff has obviously got to be able to withstand ? temperature the exhaust gets up to.

Any offerings greatly appreciated.

 

Machine shop. Thy can remove the remainder of the tap, weld up the boss to re-tap a new hole, and fix that stud that you put in off-center (the hole on the intake boot won't line up). Or you can shop for a used head, which might cost about the same or less.

Whoever tried to extract the broken studs before you was inexperienced and should have stopped before the holes got all wallered out.

 

Ok thanks k-moe. There is no remaining tap left in the socket.

I think four (?) of the studs are set slightly off-centre anyways? (if you look at the pics and the one of which I replaced, next to the damaged boss)

Only replacement heads I have seen would cost me £180-200 (inc shipping), and I would have 20% uk vat, on top of that, plus £8 for the customs 'to open it up and check it isn't firearms stuff etc) About £250 then to get one shipped over from USA - ouch!

There are some aluminium, machinable, and drillable, ultra high temperature putties (2000F) on a site over your way (Cotronics Corp.)? which I have found, but what is the temperature which the exhaust heads get up to? (there are some putties over here, but only go up to 900F)

 

All of the studs should be centered, or nearly centered in their respective bosses. The bosses themselves aren't the refrence point though, so you might be OK. Measure for concntricity off of the center of each exahust port.

I am not aware of an epoxy or putty that will bond to the aluminum sufficiently in that application. Your best bet for repair is welding. If you want to try an epoxy it won't hurt, but take the time to burn any oil out of the bosses. The aluminum is porous at the surface and any oil leaks will have soaked into the head a bit. You should also rough up the interior if the drilling so the epoxy has a strong physical bond.
A 900ºF temperaure rating should be more than enough.

 

Thanks k-moe. I will have a good look around the breakers advertised in Motorcycle News, over here, and other magazines - see if any Seca's are listed breaking.
Also do a more intensive search on 'net, see if I can source a used head.
Failing that I'll source the best metal resin (high temp), and build a new boss, drill, retap and restud (I can test the pipes being fixed up to it, before I install back onto engine?) And Thank You for the info regarding burning out old oil soaked into the headand roughing up the surface for best bond.
Regards.

 

Bought something called 'QuickSteel', to rebuild socket (workable and heat resistant for manifold exhausts, and engine casings)
Will report on results when applied and tested.
Regs.

 

Rebuilt stud socket, and replaced all dodgy studs. New assortment of nuts. Cam chain seal a bit chewed on one corner when attempting to lever head off last week? When rebuilding will add red sealer? Have looked everywhere? for replacement, but I can't find any. There was one for Maxim on ebay, but gone now. In my replacement gasket kit, it looks like there is a thick embossed blue line in the head gasket, which could be 'integrated chain tunnel seal'?
Any thoughts....?
Regards.

 

Yes the blue line is an integrated cam chain tunnel gasket. Do not put a cam chain tunnel gasket on with it, it will cause you headaches....been there. I know Chacal, at XJ4Ever in the top right corner has them, but you do not need it.

 

Thank You for that Cliffy!
Regards.