Oil filter and water pump housing clean and polish.

The oil cover housing was stripped of paint rubbed down with wet and dry and polished with autosol. 3 stainless screws replace the rusty originals.

The water pump housing came off easily, but the thermostat housing was a different story.
One screw head had already been sheared off and the one holding it in place was the old philips head which was rounded off. The top of the head was ground off which then allowed the housing to come free. I tried to use the screw stubs to undo them with a mole wrench and heat, but no luck. I filed them flat and drilled and retapped the holes in the end.

Once apart the thermostat appeared to be permanently open.

Taking the thermostat out showed the reason why its permanently open, its all bent and twisted.
I will have to find another one somewhere.

Water pump and thermostat housings polished in the same way as the oil filter housing.

Engine refurb.

The time has come for the big technical bit.
I had previously fired up the bike when I first bought it so there appeared to be no nasty rattles, but there were signs of fluid leaks.
The first picture is of the engine prior to any dismantling.

One problem during the stripdown was to take the end gears off to remove the cam chain.
The first gear to try to undo would not budge even with 18" of leverage going both ways and 15 stone weight pressing down on the levers. I decided to leave them on and take off the cams and swing the gears out from under the chain.
Somebody had been here previously, unless the Yamaha people mark the front cylinder with blue paint.





All parts laid out and marked up to go back where they came from.

The head was cleaned inside and out. Parts measured as per the Haynes manual and found to be in tolerance......so far. The valve covers have been painted with a silver grey engine paint, but look more grey then silver. I'll get some silver enamel engine paint and do the cyl. block, head and cover all one go.

One of the old container cases we throw away at work has been put to further use holding all the valve parts in order.

The cylinder head now cleaned and the valves have been lapped into place, probably one of the most satisfying jobs to do on an engine. All valves were checked with fluid and no leaks.

One cylinder bank cleaned one more to go.