David414 289 #1 Posted May 18, 2021 I just installed a stack muffler on my 1989, 414-8, with a Magnum 14 engine, from @jimkempand his workmanship is outstanding! Really happy with his quality built muffler. Couple of observations, the JK muffler is no louder than my stock muffler, in fact with a decibel meter, it is a few decibels quieter than stock. JK recommends at least 1" to 2" of clearance from the muffler to the hood. My original piping had the muffler 1" from the hood, and the hood became became excessively hot to the touch. I don't remember the stock muffler heating the hood this badly. So I changed the horizontal pipe and now have 3" of clearance from the hood to the muffler and the hood is much cooler. Out of curiosity, how much clearance do other members have running stack mufflers to their hood? And have they noticed an increase in the hood (Sheetmetal) temperature? Thanks! 2 Share this post Link to post Share on other sites
dclarke 4,032 #2 Posted May 18, 2021 Jim Kemp’s mufflers are really nice. I added a heat shield to mine and run it pretty close to the hood. 10 Share this post Link to post Share on other sites
Achto 27,575 #3 Posted May 18, 2021 The stack on my Raider 12 is abut 1 1/2" inches away from the hood. The hood gets warm but there has not been any paint damage. 3 Share this post Link to post Share on other sites
