In continuing my work on this Blast, I just pulled the primary cover off the bike, and I'm a bit confused by what I'm seeing. It appears to me that there is some vestige of what might have been a 'manual' type primary chain tensioning device left in the primary cover. What I'm referring to is the large bolt that is threaded into the bottom of the primary cover and directly beneath the 'spring loaded' chain tensioner when the cover is in place. This bolt has both a spacer sleeve of sorts on it, that fits over the bolt like a horse-shoe of sorts, then a 'lock-nut' where it tightens to the primary cover. And, there's a fiber-washer seal between the lock-nut and the primary cover itself. So, I'm just guessing here, but it looks like maybe at some point in the past, this bolt was used in a similar manner to what HD did with the primary chain tensioner on some of it's other engines.....where you tightened up the bolt putting pressure on the tensioner shoe until you reached a proper tension level, then locked it in place with the lock nut. However, that's a rather antiquated design, as most engines are now equipped with a self-adjusting tensioner....which I think is the case with this Blast motor and the spring-loaded tensioner that is attached to the inner case. If so, then what is the purpose of this bolt, spacer & nut? Is it basically just a 'plug' in the case? Basically I'm just trying to find if this thing serves any currently necessary purpose other than just being a remnant of the past? If so, what does it do? It looks to me like when tightened all the way up, and with the seal stopping any leakage of fluid from the primary case, with the spacer in place, it can't be anything more than just a glorified 'plug'! But..... I've got little to no experiece with this motor, and I don't like 'guessing' about anything!! So, if someone can help me here, I'd REALLY appreciate it! If it does still serve a purpose, I'd like to know what that is? Many thanks!! Tom D.