Navigator headaches

Just a thought and apologies if it seems like teaching grandmothers, but have you checked to see if that head is warped? In my experience if you check that all the head nuts are free running on their threads and then tighten the head down in the order shown in the workshop manual and to the correct torque setting (15 ft lbs) the lightweight engines aren't prone to blowing head gaskets providing you re-torque the head down after a couple of hundred miles of sensible running.

Agreed, I flattened mine on glass with emery paper, and it is essential that you re torque them down after a few miles.

dan

Previously Ulrich Hoffmann wrote:

My recently rebuilt Navigator engine was blowing out of the cylinder head gasket on the left side. I used a single piece composite gasket with two thin layers of copper on each side. It must have folded and crumpled when tightening the two separate heads. It?s the spigotted type.

It occured after only a few short test drives up an down the private lane to my workshop

Cleary visible here:

So my first thought was dividing it into two separate pieces but I was not sure to reuse it.

I had an extra copper one piece head gasket and cut it in half, annealed it and remounted the heads. I had to enlarge the holes for the studs slightly so that it slipped right on the heads.

Can?t tell you up to now if it is tight because I am waiting for a delivery of parts from the NOC shop for my gearbox which is dismantled because of a slipping first gear.

So I can?t start the bike right now

So better check twice when rebuilding the engines!

Hello Uli

Bummer!I have yet to put my head (s) on as I am still waiting for the barrel to be seeved but I bought a solid copper head gasket from the club shop--- it is a really substantial item. It could be re-used over and over I suspect.