Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

Sign in to follow this  

need advice on 2-cylinder Briggs diagnosis

Recommended Posts

I have the 16 twin on my 6216. Magnatron Ignition module developed an intermittant, machine would run but with an ocasional burp, but if I shut it off and tried to restart right away it would have no spark. It would require 5 minutes to cool off before it would start. $42 bucks for a new Magnatron module from Jacks small engines, has not given me any trouble since. Good luck.

Share this post

Link to post
Share on other sites
Our A-C 616 (5216 Simplicity equivalent) has the 2-cyl. B&S engine with MagneTron ignition. It's a super machine that has always had a suspicious bug we believe is in its electrical system. It will conk out sometimes for no apparent reason. It did this late last summer and will turn over nicely but hasn't coughed since. We've consulted the B&S service manual for help. We've tried a spark tester on either cylinder and don't seem to be getting any. We were told we need to ground out the other cylinder when we test one - why would this be? We haven't done that. We've inspected the magneto up close earlier last summer and it seemed a little suspect. It had kind of like a melted area on the unit somewhere (my memory is hazy). We're going to disconnect the stop wire and try for spark again. Does anyone have any other suggestionss before we head to the local mower shop for a new Magnetron unit? Thanks very much! Tom and son Peter Feldpausch

Share this post

Link to post
Share on other sites
Per your question about grounding. On the single coil, two cylinder engines both plugs fire at the same time. An ignition coil is a transformer the increases the voltage to fire the plugs. There is an input coil from the ignition, and an output coil connected to the plugs. On a single cylinder engine, one side of the output is grounded and the other goes to the plug. On a two cylinder, one plug is connected to the plus side of the coil and the other to the minus side of the coil. This way they both fire equally with only one firing circuit. A bad plug that has gone to an open circuit or a non-conductive spark plug wire will will kill both cylinders. This is why you must ground one plug to check the other. This also increases the firing voltage, since you are only jumping one gap instead of two. If you can ground at the coil, you can check both plug and wire. If you still have no spark after checking both sides, remove the input leads and use a meter to see if input pulse is present. I don't know what the numbers should be, but it should significantly change as the engine is cranked. Rod

Share this post

Link to post
Share on other sites
This topic is now closed to further replies.
Sign in to follow this  

  • Who's Online (See full list)

    • S-A
    • dhoadley
    • PhanDad
    • gwiseman
    • BLT
    • Tom45
  • Today's Birthdays

    No users celebrating today
  • Recent Status Updates

    • SonOfCreepfeed


      Thinkin' about this old girl.

      · 2 replies
    • Dean McFadden

      Dean McFadden

      Good morning peeps! I’m always searching for helpful information with my AC collection. Hope to find out new information and pass on my own experience in restoration. Here are some pics of my babies. I’m still looking for front rims for the 410 so yesterday I put the 310 wheels on took it for a drive. Working pretty good but still needs some carb work. Gotta get the 310 running next. Have a great day!😁

      · 1 reply
  • Adverts