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8. With the barrels seated on the crankcase mouth I can fit the new front slipper blade into position and bolt it up with the two M6 bolts. The cylinder head then simply slides into place over the studs, having first made sure all dowels are in place, and I'm ready to re-fit the camshaft. |
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9. As with all engines, the valve timing needs to be spot on and it's worth taking time to check and double check the timing before progressing. I've started by temporarily re-fitting the generator stator which allows me to accurately line up the "T" mark, ensuring the engine is at TDC. |
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10. The camshaft now drops into place in the head, and I've rotated it to line up this punchmark with the cylinder head flange. This will index the timing correctly. The new camchain is wrapped around the sprocket and temporarily retained with a loop of electrical wire to stop it dropping into the engine while I double check the timing marks. |
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11. Riveting up the soft link into the new camchain is a delicate job as it's easy to drop the link or its end plate down into the engine. It's possible to buy a special tool for riveting up the link but I've always got satisfactory results using a nut splitter like this. |
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12. With the camchain tensioner re-fitted to the rear of the cylinder block I can now tension up the chain. On this design the threaded sleeve winds down around the plunger until the plunger end is flush with the housing. This correctly pre-loads the tensioner spring. The new camchain was quite a tight fit, so I've set the tensioner up with almost zero pre-load for the time being. It will need checking once the engine has run. |
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13. Next, the rocker cover. I've already re-fitted the rocker arms, but these four sleeves need to be pressed into place with new O rings before fitting the cover. The sleeves and O rings will prevent oil leaking out past the head bolts. A thin smear of Blue Hylomar will seal the rocker cover to the cylinder head. |
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14. This is a convenient time to set the valve clearances. These could close up slightly once the engine has started up, so I'm setting them slightly wide. I'll be re-checking them once the bike has run after the rebuild. |
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15. All that's left to assemble on the top end is the ignition components. With the points and auto-advance housings re-fitted to the head with new gaskets and oil seals, I can lightly grease the crossover shaft and slide it through the camshaft. |
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16. The auto-advance unit fits onto the right hand side of the crossover shaft. The easiest way to fit it is to locate the baseplate first and clamp it up with its locknut. The centre boss then slides into place before engaging the bobweights and tightening the centre nut. Each bobweight is retained by a tiny circlip which needs to be carefully clipped into place. |