Timing tool

[Gregor 4,846]

I mentioned in another post, that I would like to find Tecumseh tool #670241. After some googling, and checking ebay, it seems none are to be had. Well, if you can't take Mohamed to the mountain, you bring the mountain to Mohamed. I thought I could make one, so I did. I started out with one of these,And one of these.

The second item is an adapter I got with my compression tester years ago. I have never used it, it's just been rolling around in the top of my tool box. Along with some other bits and pieces I ended up with one of these.For those curious minds out there that little tip in the end of a dial indicator is M2 X .04 I believe. Try finding on of those at your local farm and home store. Not here!

The only option I had was to drill the end on the stem of the dial indicator, and tap a 4-40 thread. It takes time and some patience. Not something you do with a crescent wrench, but it can be done. The little bent tab on the bottom is just a piece of a metal electrical box cover. Each end was drilled and tapped 4-40, and bent slightly.The adapter from the compression tester had to be drilled out to accommodate the dial indicator. I also ground each side a bit to accept a 1/2" wrench. The phillips head 6-32 screw was tapped into the side to lock the indicator in place. The indicator can be slid up and down for rough in adjustment. The 9/16 locking collar with the set screw was added to prevent the adapter from screwing too far into the head. Of course when I was all done I had to try it out, so I reassembled the H70 a bit. Put the piston in with rings, bolted the rod to the crank, and installed the sump cover. Nothing is brought to torque spec, just snugged down to keep everything in place. That's when I discovered I needed the bend in the little tab. Otherwise the indicator would bottom out on the block, before reaching .080 BTDC. The video is a bit jerky, I am trying to hold my phone with one hand, and turn the motor with the other.

 

The video loaded twice for some reason, and didn't seem to want to play,so I deleted it, and will load it again in a new post.

Edited December 31, 2020 by Gregor

[Gregor 4,846]

Video

[Gregor 4,846]

The video won't play right for me. Maybe there is a better way to load videos, I don't know, but trust me, it does work. Now that I have a prototype, and know the do's and dont's, I think I'll make another one. I wish I still had my small lathe, but I sold it a long time ago.

[Gregor 4,846]

I made another timing tool. Does the same thing, just looks better without all the mistakes from the first one. I made this one out of a spark plug, and other bits and pieces of course.

[Gregor 4,846]

For the last few days I have been sitting here patiently waiting on parts for my H70. With nothing else to do, I decided to work on that timing tool thing a little more. I have made about 6 of them, learning from each one. Now I have it down to a science. For my dial indicator anyway. It looks decent, and works perfect. When my parts do get here, I can assemble the motor, and still be able to check the timing. The one thing that has me baffled, is trying to figure out what thread is used in the plunger of the dial indicator. I even ordered a set of small metric screws. None of them fit. I tried my thread gauge from my tap & die set, nope, nothing there. Oh well, some day I will find it. I even made a video of how to make the timing tool. This video of course is for MY dial indicator, but I'm sure it can be adapted to fit others.  Poke Here  To watch the video. It's not long, and it's NOT loud.

[Gregor 4,846]

UPDATE:  I have made a LOT of timing tools, trying to get it just right. The tool I made worked well on small motors, not as handy on larger ones. So I revamped it yet again.I think I have it perfect now. It works well on my H70 (7hp) and my TVM220 (11hp)  If you do a lot with Tecumsehs, and you would like on of these tools, message me. I will sell them for the cost of parts, about $25, and shipping to you.