Norton cylinder head rebuild

I've done this for years with no known problems. Speaking of goop to use on gaskets, a Canadian guy at the Norton National told me he never used anything, on the various crankcase and gearbox gaskets. Instead, he would just soak them overnight in oil before using them.

Supposedly this made them swell up to conform to the irregularities better. I was a little dubious about soaking a gasket in very the fluid you're trying to prevent from leaking through that gasket, but his bike was sparkling, and he said it never leaked oil.

All of that straight edge business seems too hard. Is it OK to run the axle all the way against the slot front or back and back off from there? Or how about using a square and measuring space between the rim and the swinging arm tubing? I did this recently and found the side stand better than the centre. The centre stand gets in the way, and with the bike leaning to one side it's easier to get at the sides of the wheels and tyres.

Place the bike on the side stand, then get a piece of 6 x 1 or something else long, flat and reasonably light. Place the straight edge against both wheels, and with both sides of the front wheel against the edge, look at the contact points on the rear wheel. Adjust the rear wheel with regard to the chain tension so that all four contact points, front wheel and rear wheel are the same.

I did this when I was sorting out a bit of a high speed wobble and it helped considerably. This problem of installing Norton heads arises because Nortons have their pushrod tunnels permanently cast into the cylinder barrels rather than using the vast array of little tin tubes, rubber washers, etc. The Norton design was a major improvement in oil-tightness, but it makes getting the head off and on with the engine in the frame very tricky indeed if you do it the way the book says; because you're supposed to lift all four pushrods as high as possible into the head and hold them there while you lift the head out of the frame, or you won't have enough clearance to get it out.

Six hands are the practical minimum for this job, and most Brit-bikers have only two. The answer is to use a pair of nylon tie wraps the kind used on electrical harnesses, etc. As soon as the head is lifted free from the gasket, put one tie wrap around each pair of pushrods, fastening it so the long end of the tie wrap points out away from the barrel.

Snug them up tight enough so that it's a bit difficult to move them up and down on the pushrods. Now, as you remove the head, push the tie wrap down all the way on each pair of pushrods, then put a finger from each hand under the tie wrap on the pushrods to hold it up and its pair of pushrods as you're lifting the head free of the engine.

Holding each pair of pushrods this way leaves you eight fingers to lift the head out of the frame. After the head is off, keep the tie wraps on the pushrods unless you need to service them, of course , so you can tell the left pair from the right pair by the direction that the end of the tie wrap is pointing. To reinstall the head, just hold the pushrods high up in the head with a finger on the tie wrap as you did before while lifting the head loosely onto the barrel.

Once the head is past the frame and over the barrel, with the pushrods in their tunnels, you don't need the tie wraps anymore, so snip each one off while holding the long end, to be sure no nylon bit falls into the engine. Note that the only purpose of this trick is to keep the pushrods out of harm's way during removal and installation of the head. During installation, you still have to follow the book and be sure the pushrods are properly located on their rocker-arms before tightening down the head bolts, or a pushrod could be bent.

If, like the writer, you've already taken the head off by the traditional blood and chaos method, you can still put it back on with the tie-wrap method; firstly making sure the pushrods damaged during removal have been replaced and all skin lacerations have stopped oozing, which could cause rust.

You simply have to put a tie wrap on each pair of pushrods, aiming the end of the tie wrap toward the outside of each pair so you'll be able to tell the left from right.

If you've mixed them up already, you'll survive, but it's better practice not to interchange pairs. I invented this trick many years ago, and used it last October on my ring-job with no problem, even though I was out of practice. Easier head installation is probably the only good thing that can be said about separate pushrod tubes of the earlier engine designs - this trick makes Norton head removal and installation almost as easy, without giving up the oil-tightness and durability of cast-in pushrod tunnels.

I ran across a product at my local friendly Honda dealer that works really well. A couple of weeks ago, I used it to clean up the wooden artillery wheels on my old Hudson. The results were little short of spectacular, cleaning and shining paint, natural finished wood, rubber, chrome and aluminum, and in far less time than I am used to spending.

It is made in the U. In my experience, studs often pull out of alloy blocks because they have not been securely bottomed out in their threads.

Bottoming the stud so that it contacts the alloy at bottom of the stud hole preloads the thread, and minimizes fretting from vibration during use. By all means, when you discover a loose stud, re-thread its hole in the alloy block with a coarse thread, and make up a double-diameter stud to replace it. Alternatives include fitting a 'TimeCert', which is like a solid HeliCoil.

In any case, when rebuilding any engine, check all the stud holes to ensure the threads are perfectly clean, and in good condition so they retain the stud securely. Any kind of dirt in the holes will lead to early failure due to abrading the alloy threads. Jul When refilling the gearbox with oil, you can easily see the inside of the level plug from the open inspection hole by pointing a flashlight down and to the rear. By looking at it, and gauging the oil level visually, you don't need to remove the level plug, saving the mess of oil all over the exhaust pipe and frame when the surplus runs out.

Something else that may be obvious, but is sometimes overlooked, is that when you re-fill a dry gearbox, you should kick over the engine a few times, to distribute the oil inside the box, and then let it sit for a while before making a final level measurement. You'll be surprised how much it settles. Aug The sensation is sort of hard to describe, kind of like a weird vibration or something.

The cause turned out to be that the middle bolt that attaches the crankcase to the cradle had come loose. After tightening it the sensation completely went away. I just thought that I'd pass this observation along in case someone else notices a similar strange sensation in their twist grip. Try this tip for wobble, I had the problem and it worked to greatly minimize it.

Tip your bike against a wall so that it is resting on its handle bar and not the kick stand or center stand. Get a long and straight 2" x 4". Press it firmly against the front and back tyres. Do they line up? Both wheels should line up so that the both front tyre and back tyre have 2 points of contact with the 2" x 4", that is on the rims of the rubber.

If not adjust the rear tyre so that it does. Steven R. Schoner dm cleveland. Sep Drill and tap the caliper at the flat, inaccessible side nearest the spokes. Choose a bolt that is threaded all the way and not shouldered, and a thin washer I've used fibre ones.

The hole of course is so you can insert a drift and tap out any stubborn piston. I've done this on 3 Commandos with no problems.

A temporary fix is the beer can. Take a pair of scissors and cut a piece of aluminium the size of the threads on the nut. It's kind of a trick to get it in there, but if you put it in the hole in a sort of conical fashion it will catch and give enough hold to hold the pipe against the gasket. I have in the past done a 'road side fix' by using several large hose clamps going above and below the exhaust pipe around the head and then using some wire to keep the 'band aids' from slipping apart.

It held the exhaust pipe in place until I could get home and do a proper fix. The last time I did this, it lasted for the duration of my trip to Canada, over miles; so it does work, it just looks a bit strange.

When our local club secretary had his Commando catch fire and burn out after a backfire through the carburettor recently, it concentrated my mind on my leaking gas cap. Even with a new seal and careful attention to the tank rim it still poured out on the slightest lean when the tank was full. I decided it must be leaking up the shaft the seal holder slides on, but there was no access, as the end of the hollow shaft is peened over.

I ground the peened part off and disassembled it. Sure enough there is another seal on the shaft which prevents petrol taking this route out, and mine was perished.

There is no part number for it but a piece of any petrol-proof rubber pipe of a similar size cut very neatly to length will do.

When reassembling, a small washer and a self tapper took the place of the peened part of the pipe to hold it all together. A lot cheaper than a new cap! Any suggestions? Have the i. It worked great for me, though on the o. Talk to your plating company about how to insulate the area you don't want plated; I did mine with big washers. I made a tool to do this from two old clutch plates, one outer and one inner. Bolt or weld them together concentrically in line!!

Slip the tool into the clutch, engaging the inner and outer drive slots and hold the handle as you do everything up.

It works for clutch centres, and with the primary chain fitted, the engine sprocket nut as well. The length of the bar is such that it is too long to fit between the two chainwheels in the primary so that by engaging the ends into the space between the teeth on both sprockets you can jam the primary solid without loading the primary chain.

It is small enough to carry with you if you're into roadside repairs! I never even use a ring compressor. I found an easier way, putting the pistons in the cylinders before attaching them to the rods. That's easier because you can install them with the cylinder upside-down on your workbench and carefully ease the rings in place one-by-one.

If you put the inside circlips on before you do this, you can slide the pins in from the outside as you lower the cylinders onto the rods. This was so much easier that I'll never go back to the old way, at least for degree twins. A cement mixer is good for removing rust, etc from inside tanks. Just put some nuts and bolts inside, stuff in with blankets to protect outside, and switch on for a while.

I too have experienced the problem with the pickup board 's connectors. Solution-- get rid of them! What is happening is that the wires going through the board and point soldered are weakening, then breaking at the point where they enter the board.

This creates a minute break in the circuit that can be very frustrating to eliminate. The bike will run perfectly one moment, then die the next. What I did to fix mine, was to unsolder the wires, removing them from the board. Next I carefully drilled out the two holes so that short brass screws could fit through make sure the heads do not touch. Next, screw a brass nut to the other end, then solder the head to the board. Then replace the bullet end of the wires that go to the Boyer black box with regular 'Y' blade connectors, using a brass nut to secure them to the altered circuit board pickup module.

I would caution that a direct soldered set-up such as that described has failed on my bike - the wires actually fracturing within the insulation. In my experience, unless you have somehow shorted out a Boyer, all defects of the system can be found close to the backplate connectors. Curiously, the very early Boyer had screw connectors, long since discarded.

They never failed by breaking, but occasionally came undone. This gave me a great familiarity with the 'inexplicable' popping and banging and trying-to-run-backwards symptoms of an ailing Boyer, which has set me in good store a couple of times since.

A useful trick to help diagnose faulty wiring between backplate and Boyer unit: take your plugs out, switch on and move the wires around as much as you can. When you hear the plugs clicking, you've found the dodgy connection or broken wire. The outer spokes have a longer 'hook' as well as a sharper bend because they have to bend around the flange.

This sounds like the crankshaft oil seal. Crankcase pressure blows engine oil into the primary chaincase which then becomes overfilled and leaks out of the final drive. A good test is to take out the primary level plug and see if oil comes out; if it does then it was over full. If it is not clean then it has probably got engine oil mixed up in it. Treve Whitford magdis nortonownersclub. You do have to pull the drive sprocket and clutch but the primary inner does not have to come off.

When you pull the sprocket you can see the seal immediately behind it. The woodruff key needs to come out too. The hardest part is to get hold of the seal to pull it out. Centre punch first. Then with a stiff piece of wire, bend the tip to a right angle and insert in the hole as a hook yes I used a coat hanger. Pull the seal out. Alternatively, drill two small holes opposite one another in the metal part of the seal and screw in two self tapping screws until they contact the crankcase. Then screw them in evenly, thus forcing the seal out.

When inserting the new seal, it has to go in very evenly, but it helps if the sharp edge on the outside of the seal is removed with a sanding disk or file before the seal is fitted. A piece of pipe the with an i. Used with a mallet it makes the fitment of seals a breeze. Oh, and remember to oil the shaft before fitting the seal. This month's Classic Bike had an article on how to make your Commando more reliable.

One of the things they pointed out was that in the event of the rear brake cable breaking, the rear brake pedal can swing downward and dig into the pavement with disastrous results. They showed an aftermarket spring, but didn't say where to get it. I went out and looked at mine and added a piece of piano wire as a back up safety. I looped it once around the bolt that is mid position on the brake pedal, then up and around the footpeg support, then back down and around the wire.

The loop is stiff and large enough to move up and down with the brake pedal, but will hold the pedal up in event of rear brake cable failure. When fitting an oil seal and there's some danger that a sharp edge might damage the sealing lip, use kitchen aluminium foil to wrap around the sharp bits. This helps protect the seal, and can be easily applied and removed after.

I put in a new bush in my kickstart shaft and it appears that I pushed it in too far because the kickstart shaft had significant end play, about 40thou. Along with a second nut and washer on the socket I was able to pull the bush out as far as I needed. It would be easy to pull the whole thing out as well. If you have a lathe you can make the right spacers, but what's the challenge in that?

Fill the oil grooves in the section that goes into the bush of the kickstart shaft with 5-minute epoxy or the like. Complete or Partial Restorations. Complete engine rebuilding and restoration. Raise Compression and Squish Band machining. Piston-to-Cylinder clearance matching. Cylinder head helicoil and stud replacement. Complete Gearbox Overhauls. Belt Drive Modifications. Isolastic Upgrades. Performance Brake Packages. Cartridge Fork Internals.

Rear Shock Upgrades. Wheel Building. Custom Machining. The Norton Owners Club Limited. Registered in England No. VAT Reg No Norton Owners Club. Search Search. User account menu Log in. Cylinder Head Identification. RH6S, indicates a cc head fitted with cc guides Will a head fit onto an motor?

Has anybody ever tried it? Also, the identifier code over the exhaust rocker is absent, but I believe the head in question is a Combat. Has anybody else run into heads with no identifier before? Eric Lamberts ewl med.