Originally Posted by planktonnn
We (he) moved on to carb cleaning by applying carb cleaners & an airline to the idle circuit to clear the tiny galleries etc. Looking at the right carb he saw that the slider was slightly misaligned in its bore, and so he began to investigate the diaphragm. I had put new ones in at the rebuild and true to my mechanismical mangle-handedness it seems I’d failed to get the bottom tab that fits into the slider seated properly. The tab into the carb body was right but the diaphragm had been attached to the carb incorrectly and this, over time, led to distortion and subsequent slight mis-seating of the slider. It was possible to see that the diaphragm had become slightly swollen as a result of the twisting/twirling forces therefore applied to it and had stretched a little to find its own level as it were. This again reinforces the benefit of knowing what you’re looking at. So, Ian took a new diaphragm package from the nail it was hooked onto above him & reassembled the carb. I had pointed out that I thought the mixture screw on the right carb was missing its retaining spring and that the O ring was suspect. He confirmed this & hooked a mixture screw/spring/O ring from a Bing laying on one of the shelves, then we (he) were ready to refit the carbs & see where we were*
On inspecting the two side studs on each of the rocker covers he indicated the tired/partially chewed threads thereon, and cut replacements from a threaded rod, cleaned up the ends with a swift slide past the bench grinder & refitted the rocker covers. He cleaned up the spark plugs, got the whole thing back together, dropped the bench and I refitted the tank… Ian cured an overflow from the right carb bowl and I held my breath as he reached for the starter button. The bloody thing started first time and Ian moved on to balancing the carbs, that dark intuitive art about which, sadly, I am no more knowledgeable than I was last week. I could hear the differences his adjustments were making but to be frank he was a blur of tweaking & fiddling and I couldn’t steal his skills. Not even a bit. He got it roughly sorted & switched it off to give it a little chance to cool down.
I’d been meaning to change one of the rocker cover gaskets for some time as the one in place had a couple of tears in it, but I had avoided getting to it as it was only misting a little. It now became clear that the gasket had give up the ghost so he went hunting for a new one as the left rocker joint was leaking. He cleaned the faces and got the new one secure with the help of a little snot. The time had come to fine tune the carb balance…
* I was crouched down by the heater.