3 days ago, I decided to dismantle the intake manifold and check the o-rings(should I call them v-ring?) sealing between the manifold and the cylinder heads. It was hard to loose the screws on the left side of the bike but somehow I managed. When I take it out, I found out that the o-rings were roasted. I was not prepared to replace them so I didnt have any correct o-rings with me. what I did was, placing 2 o-rings per side which were real "O" rings (not V shape) and thinner than original. When I tightened the manifold back, it was almost impossible to move the manifold any more, which convinced me of proper sealing. installed the carb back, did the idle mixture adjustment and put everything back on the bike.
back cylinder was not missing any more. engine was easily starting when cold, no idle increasing after warming up, the well known harley idle sound was back, smooth throttle and so on...
From the begining, I guess this was the main cause of back cylinder missing, leakage at intake!
thank you guys for your ideas and recommends...
