My ignition works!

[zeusrekning]

I finished my transistorized ignition a few weeks ago and tried it out on an engine today. I picked up a small trimmer engine a couple weeks ago when Cedge and I were scrap yard hoping. I got the engine to halfway run this evening (high rpm needle seat is busted so no high rpm). I mounted my magnetic pick up and used the magnet in the flywheel. The switch is a magnetic switch from McMaster (used on machines to recognize the door is closed). Not sure if it is considered a hall effect switch or a "reed switch".
Anyways, comparing how the engine ran with the stock ignition versus the new one, it ran a lot better. It started with one light pull of the pull starter, ran up to a slightly higher RPM (judging by sound) and it did not shut down at wide open throttle. With the original ignition it would shut down because of too much fuel when it tried to reach high RPM (I think).
I had to let someone know it worked :big:

Side note: I had my wife come out and watch the initial firing. I had the spark plug out trying to see where TDC was so I could mount my switch. The switch turns on the ignition and when the magnet is removed the plug fires. I came into contact with the spark plug. It lit me up very well. Made the elbows hurt

I hope to try it soon an a different engine to see if it works at high RPM. ALSO thanks to Swede for the help he gave me on this project.
Tim

 

[Powder keg]

Hope you documented everything..... We want details)

Glad you had a good run, Wes

 

[zeusrekning]

This is a small side task related to my ignition build. I was able to get my test engine to run using the magnet on the stock flywheel but the RPM was limited. I assumed this was due to the small dwell angle using the stock magnet.
So what I did today was make a new flywheel with 17 1/8" magnets making a 75degree dwell angle.
First thing I did was measure the taper on the engines crank. Then I set up the manual lathe to make a small tapered mandrel. (sorry guys no CNC here I figured it was time to hone up on my manual skills before I get the lathe at home.)
I measured the angle to be 13.5 degrees. So I set the compound @ 6.75 and made a few passes.I measured the angle to be 11+ degrees, made an adjustment and finished the tapper. Finally, I drilled and tapped a 1/4-20 hole in the end.I also trued up the diameter behind the taper so it was all concentric.

Here is the stock flywheel next to a 4" billet.

Turned and faced the billet to size.

I center drilled and drilled through. With the compound still set at the correct angle I mounted my boring bar upside down and bored the taper.

I placed the mandrel I made earlier into the stock flywheel and marked a line where the taper stopped. I used this as a gauge to get my taper diameter close. I actually machined the taper a little large and cut material off the face till the "gage" matched up.

I then turned the part around and faced off the extra matl and bored the large counter bore.

Then to the mill we go.
I set up the "spinney jig" with a collet holding the mandrel I made. Mounted the flywheel and found center using the pointy end of my edgefinder.

I then used a small center drill to mark timing lines every 5 degrees. Then I center drilled ,drilled, and reamed 17 .124" holes 5 degrees apart. SAS my drill broke on what was to be the last hole. I was allready putting in an extra hole so I just pretended this one wasn't to be there. If it had broke in any hole other than the first or last I'd been screwed.
After I got home I cleaned the flywheel up and pressed the magnets in using my "banger" press and black loctite.

I'm going to sneak outside now and see if I can get a better video if it running. I was able to get a couple runs at high RPM but I'm still having carb problems.
Tim