Triple cylinder head camshafts and valve gear

If you have already measured and adjusted the camshaft clearances on the valve stems then you have already experienced most of the work necessary to remove the Triple's cylinder head. The first procedure will detail head removal with the engine on the bench. The second one gives further wrinkles for removing it with the engine still in the frame.

Follow the full instructions given in the Maintenance section for valve clearance measurement and adjustment to the point where both camshafts are removed from the head. It makes good sense to go through the measuring sequence because you can avoid repeating it at a later stage if you are not actually going to work on the head once it is removed.

Now proceed as follows. First undo and remove the cam chain tensioner body which is fixed by two setscrews and washers. It should just pull away. Pick off its gasket as well.

At both the back and front of the engine, at the foot of the camchain tunnel there are two studs which fix the head to the barrel. Undo and remove both their nuts. To remove the camshafts you will have to undo the majority of the head stud nuts. There are however eight more to go. Two appear at each far side of the head, then there are two to the right of the camchain tunnel and four to the left, all six being in the centre'. Undo these with a progressive and diagonal motion so as not to tension any one unduly. The head should now be ready to lift off. In theory you should be able to lift it straight up, however, they often stick. Tap the head casting with a hide-headed hammer. If this does not work then turn the engine over on the crankshaft (you should not remove the plugs whilst taking off the head to avoid bits dropping in) and the head should pop up under compression. Hold the camchain end wires and pass them through as the head is lifted. Tie them back once the gasked is off. If care is taken not to break the cylinder head gasket with the front stud when the head is lifted, the gasket can be used again. Do not lose the 4 O-rings. This late type gasket with O-rings can be used on earlier Triples.

Be prepared for the barrel to come up too. Once you have lifted the head off the studs carefully place it on a bench. Then inspect the head gasket which should still be sitting on the barrel. Two types of gasket have been fitted. The first type was just a straight copper asbestos gasket. The second type, and the sort which should ever be fitted today, is the O-ring type. This gasket has large stud holes on the four outer main studs so that O-rings can be placed on those studs enabling the gasket to sit around them, and not over them. O-rings come with the new gaskets. Inspect for gasket blowing streaks. Lift off the gasket. Now undo and remove the camchain tensioner blade after its setscrew. This is found at the back of the engine. The blade should lift straight up for inspection. The setscrew fixing should have two washers. The top one is steel, the other copper — these must be fitted otherwise the setscrew will foul the camchain.

With the engine in the frame the cylinder head can be removed with a little more difficulty. It means removing the head studs! There are thirteen of them (in fact, 13, made up of 12 long 9mm ones coming all the way up from the crankcase and 1 x 8mm stud at the inlet camshaft centre bearing). The inner ones, directly under the top frame tubes are the problem ones because they hit the tubes as they are drawn up. They will pass the top frame tubes if you 'bend' them slightly using a ring spanner as the bending lever. The right nand side, back one is the problem stud. It's quite possible if you go gently. Ignore the two outer studs at each end of the head. You will have to use the 'double nut' method for each stud, i.e. lock two nuts onto each other on the top stud thread and then unscrew the stud using the lower one One stud in the centre will not remove. Lift the head, swing to one side, and them remove that stud with the head. The head will not foul the frame as it is removed.

Replacement of the cylinder head is a straight reverse procedure of its removal. The gasket can only be fitted one way up. Don't forget the O-rings. Be very strict about cylinder head torqueing. The engine must be COLD. Replace ail the washers and shims as you found them. Now go back to the Maintenance section and re-read the valve clearance checking and adjusting procedure which includes camshaft replacement etc.

Full details have been given in the sub-section following on the camshafts and valve gear. Here are some extra notes which will help the small differences between them to be better understood.

NOTE: The Triples's camchain tensioning arrangement is different in that it relies on removable tensioner blades rather than tensioner and damper wheels although the tension adjuster does use a wheel to position the tensioner blade but this wheel does not wear. The tensioner is a 'hydraulic' piston which is acusted to press the tensioner wheel onto the tensioner blade which then rides on the camchain The component drawing will explain the various positioning. An anti-vibration 'strap- sits on trie inner side of the camchain opposite the tensioner blade. It simply hangs in the barrel and can be readily picked out once the cylinder head is removed. (The barrel has to be lifted a hai: inch or so to get the strap out. When refitting it, make sure that the thicker part of the strap is up ar c this its 'cross piece' at the lower end enters the slot in the crankcase.) Both the blade and strap will wear and should be replaced when that readily shows.

Under the crankshaft the camchain rides over what the factory call a 'protector'. This is a removal pedestal which is yoke shaped and simply follows the camchain around on the crankshaft sprocket just close enough so that the camchain cannot jump off yet not so close that it touches. This protector can be removed from the underside of the crankcase. Its removal often allows small pieces which have been dropped into the cranxcase to be removed. It also allows a camchain to be replaced onto the crankshaft sprocket should it have been pulled through without dismantling the engine!

NOTE: Early engines did not have inlet valve stem oil seals fitted. These can be retrofitted and they are desirable. Also early Triple valve spring caps were weak. They often shreaded and caused nil valve clearance. Very early engines (up to 1806) used cast iron tappet bucket liners. These were dispensed with, the bucket running direct in the alloy.

NOTE: Engines up to frame number 3887 did not use removable valve seats, because the combustion chamber was a cast iron skull with integral valve seats. Thereafter, valve seats were listed as spare parts as the skull was dispensed with, the combustion chamber being machined in the alloy. Soon after the factory returned to the cast iron skull!

REMEMBER that Laverda do not design anything twice, if they have got it right the first time. Therefore, they did not completely revise the Triple's head and valves from those of the Twins. The number of cams is relatively unimportant.

Laverda 650 Vicenza

Although in this photograph the cylinder head is still It's best to use a pair of pliers to lift out the tensioner fixed to the barrel, the camchain tensioner blade fixing blade for inspection screw is properly shown

Note the offset drillings for the camchain adjuster's cover fixing

A late type Triple head showing one of the handsome domed nuts fixing the head, adjacent to the outer

This is the stud and nut at the toot ot the camcnain tunnel at the front of the engine. Use a ring spanner

The screwdriver points out the little O ring over the stud, with the cylinder head gasket beneath it

Laverda 650 Vicenza Kawasaki 550 Head Gasket Leak

The Triple's crankcase is very similar to that of the Twin although its breather and alternator cover are obviously different

Crankcase Breather Suzuki 750
0 0

Post a comment