Since day one, my 2005 Suzuki GSX-R1000 has had a bothersome top end rattle, even when it had low miles. After a few years and 26,000 miles later, the rattle seemed to get worse. I checked valve clearances twice (once at 17,000 and again at 26,000) and all clearances were in spec. I knew there had to be a way to quiet the top end down, so I asked around.
Most of the mechanically inclined friends I spoke to said it’s rare for cam chain tensioners to go bad and I should just try to push the stock tensioner out a click to see if that worked. I tried this. No change. Though I respected their opinion, I was convinced there had to be a better solution.
Not too long ago, a friend brought a 2005 Suzuki GSX-R1000 engine to me to rebuild after it started knocking at a race. Two of the bottom connecting rod bearings had spun out after just six laps. I rebuilt the engine and noticed it was equipped with a manual cam chain tensioner. I had never used one before and really had no clue what the advantages were so I started doing some research.
Automatic CCT’s vs. Hydraulic CCT’s
What I found out is the automatic cam chain tensioners that come stock with a Suzuki motorcycle (for example) have a ratchet type mechanism that holds the push rod of the tensioner to the cam chain guide and maintains tension. But after continued high r.p.m. use, it is possible for this ratchet mechanism to weaken and thus dull or wear the teeth on the push rod. This can cause the tensioner to slip which creates noise or worse, inflicts damage.
On the flip side, hydraulic tensioners use oil pressure to determine how much pressure to put on the cam chain guide and cam chain. These types of tensioners actually have a tendency to put too much tension on the chain guide under high r.p.m.s or high oil pressure conditions like during start-up. This could result in premature wear of the cam chain guide and other components, per APE Racing. Additionally, if there is any foaming of the oil or the engine loses oil pressure, this can also cause the cams to go temporarily out of time and you’re back in the same boat you would be in with a faulty automatic cam chain tensioner. The
APE Racing Manual Cam Chain Tensioner
I found the APE Racing Parts website online and starting reading about the manual cam chain tensioner (or MCCT for short). The MCCT is designed for the racer who frequently adjusts or makes changes to their engine, per APE Racing. This means the MCCT will have to be adjusted every oil change, but I believe a happy, humming engine is worth it. APE Racing’s MCCT can eliminate the possibility of the tensioner being too loose or too tight as the mechanic can set the tension himself (or herself). The tension will remain the same, regardless of oil pressure or r.p.m’s. What does this mean? The possibility of engine damage goes down dramatically and the engine runs much quieter with better performance.
As APE Racing MCCT’s are CNC machined from billet alloy to exact tolerances, they fit perfectly to the gasket surface of the engine with no modifications needed. This makes for a quick install with little hassle. After reading this information on APE Racing’s website, I was convinced the MCCT was the answer I’d been looking for.
The part number of the MCCT I received was ST1000-3-PRO. I know this one works on more than just one year/model GSX-R. Click here to see what models APE Racing currently make manual cam chain tensioners for. I did appreciate, though, how they had a link to the “how-to” page right on the packaging. And I know this is going to sound really girly, but I love the color of this tensioner too!
I removed the valve cover and made sure the engine was on TDC or top dead center where the cam chain is at it’s slackest point. I checked to make sure the timing marks on the crank shaft were correct and lined up. I also checked the position of the intake and exhaust cam sprockets and marked them with a paint pen (both on the chain and on the sprocket itself) in case I needed to reset time for any reason.
I removed the original, stock tensioner and placed it in a baggy.
It should be noted that I removed the oil feed to the tensioner body and placed it in the baggy as well. The APE Racing MCCT will not install correctly if this oil feed nozzle is not removed.
I then cleaned the gasket surface at the CCT opening.
I loosened the jam nut on the MCCT and pulled the tensioner push rod all the way back up against the body. It’s best to do this when on installation to prevent the cams from jumping time as it would be prematurely set too tight.
I installed the gasket to the MCCT body.
I installed the MCCT, tightening down the body first and torque-ing the two body bolts to about 16 ft. lbs.
I screwed in the tensioner foot or push rod while turning the engine clockwise slowly until I felt resistance against the cam chain guide. I must note it was really difficult to feel where the best stopping point was, so I screwed the push rod in until it nearly stopped, then backed it out half a turn. I turned the motor clock wise at the crank shaft and checked the cam chain tension. It should have had a 1/4’’ deflection but it was extremely tight, so I loosened the tensioner another half turn, tightened the jam nut and turned the engine clock wise again. I checked the chain tension and my timing marks and everything was spot on!
Before I put the bike back together, I also installed NGK iridium spark plugs and swapped out the coolant. On start up, it purred like a kitten. It literally sounded like a completely different bike. All the top end rattle was absent. It was so quiet! I was so impressed at how quick and efficient the install was and how much of a difference it made! I was not expecting such a drastic change. The APE Racing MCCT really is an amazing, simple solution to an annoying problem. I highly recommend it to anyone who doesn’t mind spending extra time working on their bikes.
More about APE Racing’s MCCT
The APE Racing MCCT is available with the bolts and gasket included and is available at an m.s.r.p. of $51.65 for standard model tensioners and $89.95 for pro series tensioners.
Take a look at this detailed video on how to install the APE Racing manual cam chain tensioner on a 2005 Suzuki GSX-R1000.