Review by James Parchman
[This APE Motorcycle Cam Chain Tensioner Review was originally published in the January 2007 issue of Rider]
In his book Advanced Engine Technology (London: SAE Intl., 1998) Heinz Heisler provides a first-class explanation of the workings of an overhead-cam motor and the methodology for keeping its camshaft(s) running true and tight. In fact, 794 pages of information you might consider if you have a deeper interest in the topic. We delved slightly into the subject, looking for an explanation for the screeching emanating from the top end of our well-worn Kawasaki Concours. The sound was similar to that of a trowel being run over a brick wall; annoying, but seemingly not affecting the Connie’s performance.
Herr Heisler’s book was helpful but we needed a second opinion. Because Kawasaki has kept the Concours around and unchanged for so long, there’s almost no problem not previously encountered. The Concours Owners Group (www.concours.org) has an Internet forum where all things Concours are daily discussed and debated. COG members seemingly have two things in common—knowledge of and affection for their chosen machine, and a frugal nature. Exactly our kind of people!
Research and discussion with COG members led us to believe the culprit was a faulty automatic motorcycle cam chain tensioner. Options for replacement were the original spring-loaded version, a ratcheting tensioner Kawasaki upgraded to in 1990, or an aftermarket model. Owners of even newer Concours complain about adjustment progression of the OEM part, so we decided on a manually adjustable tensioner from APE Raceparts. The fact that it was considerably cheaper also didn’t hurt.
American Performance Engineering manufactures and distributes a multitude of engine and powertrain products for Japanese bikes and soon will do the same for Harleys. Operating for 32 years, APE caters to the motorcycle racing market in a big way, but also manufactures parts for street and offroad use. Besides manufacturing most of their own parts, APE offers custom machining of cylinder heads, crankshafts and transmissions. Jay Eshbach is the very involved owner of the company, which recently moved to new facilities adjacent Willow Springs International Raceway in Rosamond, California. The company Web site is most informative concerning its products and what’s shakin’ in the world of motorcycle drag racing.
Purchase was accomplished via telephone for $51.65 plus shipping, with delivery a couple of days later. Finely machined of billet alloy, the part is designed much simpler than the OEM version. Like Kawasaki’s unit, APE’s product comes with an O-ring seal, but we suggest you request the nylock nut to prevent possible oil seepage. Alternatively, Teflon tape and a liberal dose of gasket sealer will do the trick. Instructions are included and the entire remove/install/adjust process took less than 30 minutes. An extra set of hands is helpful during the adjustment process.
Did the screech disappear? Yes! Now the four cylinders whine happily again, and after several thousand miles no tweaking has been necessary. COG members report 10,000-plus miles without adjustment, with the ability to fine-tune the process as needed.
Kawasaki’s venerable ZG1000 Concours may be replaced for ’08, but for the thousands built over the last two decades this simple product helps change Connie’s scary screech into a pleasing purr!