tommyg 152 #1 Posted April 28, 2015 This might be a stupid question, but I was trying to check the rpm's of my Kohler K series 18hp on my D-180. It's a twin cylinder, of course, but my 30 year old RPM meter only measures 4,6 and 8 cylinder engines. With the dial at 4 cylinders, does it make sense that if the meter measures between 1700 and 1750 RPM that it's actually running about 3400-3500 RPM at full throttle? If so, since the engine is rated at 3600 RPM at full throttle, would I benefit from making a slight adjustment or should I just leave well enough alone? Share this post Link to post Share on other sites
WH nut 553 #2 Posted April 28, 2015 Its up to you, but they say to run at 3600 for best result. Share this post Link to post Share on other sites
pfrederi 17,185 #3 Posted April 28, 2015 I use one of the cheap digital optical tachs. I am not sure about your tach reading remember a D200 coil fires both cylinders at the same time...one is wasted on the exhaust stroke not sure how that affect you interpretation of the readings. Share this post Link to post Share on other sites
Wishin4a416 2,189 #4 Posted April 28, 2015 Here is what I use. An optical photo tach I reckon. It reads off the flywheel screen. Real easy to use. Share this post Link to post Share on other sites
Anglo Traction 759 #5 Posted April 29, 2015 If it helps, this was discussed some time back and covered the use of Laser based Tachometers, an item I find invaluable for setting engine speeds of any number of cylinders. Here is a link- Share this post Link to post Share on other sites
tommyg 152 #6 Posted April 29, 2015 If it helps, this was discussed some time back and covered the use of Laser based Tachometers, an item I find invaluable for setting engine speeds of any number of cylinders. Here is a link- Thanks Anglo Traction. Seems like this option would would not make any difference in the number of cylinders. The one I was using recorded spark from the coil. Share this post Link to post Share on other sites
WH nut 553 #7 Posted April 30, 2015 This is what I use http://www.treysit.com/9.html Share this post Link to post Share on other sites