Jump to content

Garden Tractors and Parts on eBay

- - - - -

'71 MM 112 Hydro "Too good for the junk yard"

  • Please log in to reply
20 replies to this topic

#16 Ranchero50 OFFLINE  

  • Member
  • Member No: 85038
  • 24 Thanks
  • 7 posts
  • Location: Hagerstown MD

Posted October 27, 2016 - 03:51 PM

Cool, thanks Mark.  I'll have to fab one up.  I was thinking of making it from Trex or something similar.  I did end up figuring out why it wouldn't start and also why I was nuking the wiring.  The 230 cca battery was good but buzzed the solenoid.  I ended up with a Deka 350 cca that also buzzed the solenoid.  I then found that Jacobsen energizes the field winding by pulling in the regulator coil with the switched side of the starter solenoid.  if the field doesn't get energized the generator won't start the engine and the solenoid will buzz.  Vice versus, when I was tinkering with the regulator I tripped the field winding with the engine off and it tried to start the tractor and nuked the field coil wire.


I'm trying to wrap my head around a way I can use a diode to keep the field winging voltage from trying to start the tractor when the regulator messes up.  I could wire the start coil pull into the low amp side and then use a diode for the charging side.  I need to sketch it out and see which way the current flows in start and charge.  Still haven't found a decent wiring diagram (might have to draw one).


Also in other news, my buddy who owns a bunch of these is off work with a busted hoof so it'll be a while before I get the manuals to scan.



#17 VintageIronCollector OFFLINE  


    Immersed in Tractors

  • Senior Member
  • Contributor
  • Member No: 33118
  • 1,424 Thanks
  • 1,857 posts
  • Location: New Freedom, PA

Posted October 28, 2016 - 03:44 PM

I have yet to see an MM manual! We have plenty of Ford, Jake and a few Olivers.

they made MM manuals. I have a few

#18 Ranchero50 OFFLINE  

  • Member
  • Member No: 85038
  • 24 Thanks
  • 7 posts
  • Location: Hagerstown MD

Posted November 18, 2017 - 07:32 PM

So, a year later and the old girl is still going strong.  Ran into issues where the fuel pump sprung a leak and the carb needed some cleaning.  Found a diaphragm kit for the pump and did the carb without buggering the gaskets.  Runs really well for mosing my 5k square feet of grass.  I did restore the bottom seat cushion but carefully pulling the staples and replacing the dead foam with new stuff from Walmart.  Stapled the original material back down and it's so much nicer to use.  Still haven't gotten around to installing the battery cover since I'm charging the battery every couple weeks to keep it happy.  Not sure why the new battery is discharging slowly.  No discernible drain.  Thinking a disconnect switch is in order and a cigar lighter so I can plug a trickle charger into it.


I gave up on the project blower and am looking for a 2 stage Jacobsen for it.

  • KennyP, jpswift1, Mark 149 J. and 1 other said thanks

#19 KennyP ONLINE  



  • Super Moderator
  • Staff
  • -GTt Supporter-
  • Contributor
  • Member No: 2253
  • 39,143 Thanks
  • 46,319 posts
  • Location: Collinsville, Oklahoma

Posted November 19, 2017 - 04:08 AM

Glad you came back with an update! Sounds like it's not charging well.

  • jpswift1 said thank you

#20 olcowhand OFFLINE  


    Red Tractor Nut & Diesel Addict

  • Staff Admin
  • Staff
  • -GTt Supporter-
  • Sponsor
  • Contributor
  • Member No: 20
  • 41,900 Thanks
  • 31,637 posts
  • Location: South Central Kentucky

Posted November 19, 2017 - 10:40 AM

Maybe you could upload some new pics directly to this site?  

  • jpswift1 and Mark 149 J. have said thanks

#21 jpswift1 OFFLINE  

  • Senior Member
  • Member No: 69996
  • 721 Thanks
  • 576 posts
  • Location: Buffalo, NY

Posted November 20, 2017 - 02:00 AM

What a story!  I'm so glad to hear that you saved it from the junkyard and gave it a good new home.