S&S 97ci Big Bore Kit Part 1- Tech

This past August, a few weeks after Sturgis, we got a call from our friend, Norm, on his way home from a long, winding trip to and from Sturgis. After covering several thousand miles, several breaks-downs, mishaps, and the typical delays one might expect on a three-week trip, Norm called to check in and mentioned he'd heard a weird noise coming from his primary and was going to take it easy and limp it back to our garage where there were the proper tools to check it out. A little while later he pulled up in the driveway and right away we could tell that the noise wasn't coming from the primary, it was coming from the lower cam chest area. Norm mentioned that as he rode, the noise increased and he too noticed that it wasn't coming from the primary.

Norm's bike is an '02 Fat Boy (carbureted) and had just crested the 60,000 mile mark. As we rolled the bike up on the lift we asked him when was the last time he had checked the cam chain tensioner shoes. Norm had this look of deep thought, and replied, "Actually never." Now to his credit, Norm does most of the upkeep and maintenance on his bike and for 60,000 miles he hasn't had any major problems. The bike fires right up and just goes every time he gets on it. Many people out there are the exact same way with their bikes. It's kinda like the dentist. We all know we should go in for regular checkups once every six months, but we usually wait until there's pain or something unexpected happens like getting your front teeth knocked out in a bar fight, before we pay a visit to Dr. Scrivello. But as they say "preventative maintenance, is the best maintenance."

With the knowledge that the shoes hadn't been inspected, we were pretty sure it was going to be the tensioner shoes. And as soon as we had the pipes and cam cover off we could see that the shoe was definitely worn. As we pulled the shoe away from the chain we could see that the center was completely worn to where it was metal to metal, the chain was running against the arm which holds the shoe in place. That was just the outer shoe, there was the secondary shoe on the backside of the cam plate to inspect as well. Using a flashlight and a small multi-angle, telescoping mirror (like dentists use) we were able to get a peek at the other shoe and noticed it was in worse condition.

Overall it wasn't a very good position to be in because that meant that most likely there was shoe debris and maybe even metal bits circulating which could possibly score other internal parts or get caught up in oil passages and lead to other damage. Aside from replacing the shoes, it also meant making sure there was no debris left behind which meant thoroughly cleaning up the cam chest, checking oil passages, and draining/cleaning the oil tank.

As Norman contemplated his next move, being that his bike was nearly seven years old, and had quite a few miles on it his first thought was to get a new bike with the 96ci engine, but that would mean making monthly payments once again (the '02 is paid off). So the next logical thought was since he was going to have to dig into the cam chest he might as well add some performance in the way of a set of new cams. And since he was going to add cams why not go with a set of gear drive cams, then he wouldn't have to worry about tensioner shoes wearing away. Then Norman figured if he's going to upgrade the lower end he might as well hit the top end too. At this point we interjected and mentioned that we'd heard that S&S was about to release a new big bore kit that would take a 88ci TC to 97ci with no machine work. As expected Norman's eyes lit up.