Engine Assembly – Cylinder Head

I’d previously blasted and painted the cylinder head, so time for valve lapping and new valve seals then assembly plus new stainless studs and dome nuts, so I don’t have all the problems I did when taking the engine apart.

Gallery shows before and after lapping valve.

I set the valves on the bench and bought the Suzuki tool, which makes the job very easy and was dirt cheap, you’ll also need some angled feeler gauges.

Just make sure you have the piston at top dead centre on the compression stroke. To do this rotate the engine anti-clockwise and watch the inlet valves open then continue rotating until the rotor timing mark is aligned which the mark on the crankcase.

Couldn’t find any specs on the o-rings for the valve covers, so bough several and did trial and error until I worked out the right size 65mm ID. I’ve read several times about the covers leaking so went for a 3mm thick o-ring which should sort that problem.

All of the head cover bolts were replaced with stainless ones, I could’nt get stainless flange bolts for the two long bolts, so had to settle for allen socket ones and don’t forget the two sealing washers on the two inner bolts.

One thing to note I’ve photoshop’d an image of the cam to show how the sprocket should be fitted, as I found several posts on forums where people were fitting the cam and then aligning the wrong thing. The tab washer fits over the guide pin and its the guide pin that sits at two o’clock when fitting the cam NOT the hole next to 32E.

The cam must also be fitted with the sprocket off, as there isn’t enough clearance to fit an assembled cam. Just ensure you have the cam white dot at the top and have something covering the cam chain hole, as you can only fit one bolt at a time and have to rotate the engine to fit the second bolt, very easy to drop one into the engine. I replaced both bolts and the tab washer.

Cylinder Head Cover Bolt Sizes – refer to image in gallery

1 M6 x 25mm 7 M6 x 115mm
2 M6 x 25mm 8 M6 x 55mm + sealing washer
3 M6 x 30mm 9 M6 x 55mm + sealing washer
4 M6 x 115mm 10 M6 x 30mm
5 M6 x 55mm 11 M6 x 25mm
6 M6 x 55mm 12 M6 x 25mm