[Mecchanica]

What does the spark look like? Blue, and makes a snapping sound? Or yellow and quiet? Plugs new?
Do you have a compression guage? If not, put your thumb over a plug hole, press down firmly, and give it a good kick...you should feel heat on your thumb and it should vigorously blow your thumb off the hole.
With the ignition off, tickle the carb and kick the engine over to get the fuel into the cylinder. Do the other side. Ignition on and kick.
I set the idle mix screw for initial start up at one revolution out. Turns to me are 180 degrees. So, to avoid confusion, I'll use the word "revolution".

 

[Mecchanica]

The two and four thou. settings are for 650 engines with stock cams. The 77 uses a higher lift and longer duration inlet cam using STD. radius tappets, and a weird weenie exhaust cam which uses R tappets. The settings for the 77 should be .006" on the INTAKE and .008" for the EXHAUST. Yes, more for the exhaust than the intake.

 

[Mecchanica]

Then Haynes is clearly wrong.

 

[Mecchanica]

Right, I got it backwards, the larger is for the inlet, smaller for the exhaust, opposite from what you would think. That is because of the exhaust profile and the flatter R tappets in the exhaust side and the more agressive Thruxton profile and higher lift on the inlet cam.

[ This message was edited by: Mecchanica on 2006-12-08 15:18 ]