richp 0 Posted October 8, 2007 I installed a tiny tach on my 4040 with Onan twin. It worked on another tractor I had but now it reads real high. At idle it reads 3200 rpm's and at top speed, over 4000. I know it is running way under these numbers by sound. I have the wire that is spiraled around the plug wire on just one wire. I think I have a good ground to the block. Anyone else have a problem like this? Share this post Link to post Share on other sites
Ronald Hribar 84 Posted October 8, 2007 I think and D17 can correct meif I'm wrong. But doesn't the onan fire on both cylinders at the same time, whether it is compression stroke or not. Probably not worded right either Share this post Link to post Share on other sites
RayS 79 Posted October 8, 2007 which tach do you have? Does the 2 cylinder Onan fire 1X per revolution? http://www.tinytach.com/tinytach/gasoline.php Share this post Link to post Share on other sites