Bucko 10 #1 Posted July 19, 2018 In my search for setting the timing on this H55, I have found the following: 1) Get a dial indicator. Set it to .080 2) Remove the head to locate the piston at .080 BTDC (before top dead center) Note: The specs indicate to set BTDC of the piston to .50, but under a load, the engine runs best at .080 BTDC 2) Set the point gap to .020 Here is my question: should the points be completely open when the piston is at .080 BTDC? Share this post Link to post Share on other sites
gwest_ca-(File Mod) 10,503 #2 Posted July 19, 2018 Here is some info from another service manual that likely answers your question. It states points start to open at .xxx" before TDC depending on the size of the engine. Click on the picture first. Garry Share this post Link to post Share on other sites
Bucko 10 #3 Posted July 19, 2018 Thanks! Looks like an H55 has a displacement of 12.176, and therefore on pages 281 and 282 it states that the points should start to open when piston is at .090 to .0100 BTDC. Other posts have mentioned using .080 as the BTDC, and yet others have stated the spec being .050 (although this one has an effect on the engine bogging under load). I will use a bench mark of .080 to .090, and see what happens. Share this post Link to post Share on other sites
oldredrider 2,547 #4 Posted July 19, 2018 Long ago, before I got a dial gauge, I would use a nickel to set tdc timing. Worked every time. Just a FYI. 2 1 Share this post Link to post Share on other sites
Bucko 10 #5 Posted July 20, 2018 7 hours ago, oldredrider said: Long ago, before I got a dial gauge, I would use a nickel to set tdc timing. Worked every time. Just a FYI. How did this work?I'm guessing you placed the nickel on the top of the piston, and when the nickels top was level to the top of the cylinder, that represented the piston was at a good BTDC to check that the points began to open? Share this post Link to post Share on other sites
oldredrider 2,547 #6 Posted July 20, 2018 Exactly. Works out well. If I remember correctly, a nickel mics at .077. Share this post Link to post Share on other sites
Howie 882 #7 Posted July 20, 2018 I use a washer that mikes in the proper thickness lay it on piston use a square or piece of steel on block, bring piston up so it touches the square. Points must be set to .020 before attempting to set timing. After piston is set at proper distance, rotate magneto until points just start to open. Can use an ohm meter or even just a small piece of paper between points. When it pulls out lock down. 1 Share this post Link to post Share on other sites
Bucko 10 #8 Posted July 20, 2018 Amazing! The nickel trick will be checked by me this weekend for sure. I went and purchased a dial indicator setup, and will see how precise the nickel is. I had assumed when I installed an ignition mag/coil that was missing initially that the timing was set once before, as the two raised lines where in exact alignment. I have no observed spark, so I've ordered a new coil, condenser, and points set. Once these are installed, I will also dial in the BTDC timing. In searching, I've found listings for .050 from a Tecumsa spec manual (but many say the engine has no power under load at this setting), .080 for good operation. So I figured anywhere in the .070 to .080 range should be good. I just want to get a spark; my kingdom for a spark! If after replacing everything having to do with getting a spark, and it not working, I'll be the mad person running down the street, and getting locked up as a loony. Share this post Link to post Share on other sites
formariz 11,862 #9 Posted July 20, 2018 REFER BACK TO YOUR OTHER POST!! Share this post Link to post Share on other sites