Johnson 115 Running Rich

Hello Randy,

      I just recently bought a 1992 nitro tracker with a 115hp Johnson motor. The motor starts up fine but it seems to run too rich (black tip spark plugs). I would like to know if there is any type of adjustment to make to keep it from running so rich? Or if a sensor of some sort needs to be looked at or changed?




If the motor runs good then leave it alone. The 115s of that era are kind of detuned to survive on the fuels we have now. If you jet it close to the edge it will probably fail as the "cushion" will be gone. It only takes once and the wallet will be thinner. You may want to have the thermostats checked or changed as that would cause such a symptom.  




Please submit whatever questions you have to  All questions and answers selected will be displayed on this page as they come in.  Note: though all boaters are welcome, priority may be given to I.H.R. members.  Randy can not be held responsible for any advice given.  Though his information and expertise is second to none, he has no control over what you do with your boat.  It is up to you to boat safely and act responsibly, and his advice is only to be used as a guidance for your high performance boat/motor of which you are the one responsible for the risks involved.

Mark C.


[ Home l About I.H.R. l History l Models l Registry l Members' Pictures l Feature Article l Tech Talk ]
[ Literature l Events l Top Guns l Guest Boat l Classifieds l Video Gallery l Racing Corner ]
[ Prop Slippage Program l Animated Videos l Screen Savers l HIN Decoder l Links l Contact Mark ]