312-8 to electro 12

[mark in ny 27]

is it possible to swap a newer k301 to a older hydro unit? pulled the head off the electro motor to see I have oil in the combustion chamber but I have a 1986 parts 312-8 sitting here that runs great. I just like the hydro better for snowblowing.

[pfrederi 17,116]

Easy.  Assume you 1986 is a K-301 also that it has a 15 amp Charging system not a 3 amp unregulated..  Only issue what ignition did your Electro have.  If it had a Magneto or breakerless you will have to change the ignition switch. You should also use the regulator from you donor tractor as the The 15 amp stator in your 312 would overload the 10 amp ;likely in your Electro.

[mark in ny 27]

I believe everything is identical as far as ignition I'll have to look at charging though if I have to pull everything off the 312 to swap to the electro 

[953 nut 51,480]

A 1986 312 came with battery ignition system and the Electro came with a trigger unit that is not the same. You would need to change the ignition switch and some wiring but it can be done.

The charging system is not the same so use the drawing attached as your guide.

 

[pfrederi 17,116]

 

Really need to be sure about what each engine has.  if you have the 3 amp unregulated system on your Donor you have a problem.  The Electro's electric PTO will draw more power than your charging system can supply.  Electros depending on year may have had Breakerless or Magneto or battery igniton.  Even if it came with breakerless it may have bee replaced at some point.

[Ed Kennell 35,581]

Why not use the manual PTO off the 312.    Should be an easy installation. If you can find the  old style  Raider  engagement hardware.   

[mark in ny 27]

I believe everything is identical as far as ignition I'll have to look at charging though if I have to pull everything off the 312 to swap to the electro. The electro has been converted to manual at some point. I probably should have mentioned that earlier sorry guys.

[pfrederi 17,116]

If both engines are battery ignition (beer can coil)  You are all set.  Manual PTO makes the charging system a non issue.  Even if new one has the 3 amp unregulated charging system hook up will be easy just by pass eh regulator on the electro run the charging lead direct to the R terminal on the switch.

[mark in ny 27]

I'm on the fence though because it also seems pretty easy to through a set of rings in as well if I'm pulling the engine I can just flip it over and swap the piston as well. Runs smooth just burns oil so it's a toss up especially since most stuff in ny here is closed so I'll be home at night. Anybody use the ebay connecting rod and piston kit? 

[mark in ny 27]

Also 312 8 has a hoop engagement while my charger has a bar mounted like the above picture. How do I swap out to make it work? Thanks

[pfrederi 17,116]

I am having a hard time following this a couple pictures of your Machine and new engine would help.  For simplicity I would just use the PTO currently on the Electro you can put it on the new engine. The pivot rod circled in blue will bolt to the new engine and the PTO bell and friction plate will fit no problem.

Edited March 25, 2020 by pfrederi

[mark in ny 27]

1 minute ago, pfrederi said:

I am having a hard time following this a couple pictures of your Machine and new engine would help.  For simplicity I would just use the PTO currently on the Electro you can put it on the new engine.

My pto currently on my electro is what ed posted in which it has a slot on the end that engagement arm slides into. My 312 has a hoop system how do I interchange the pto system I guess is my question coming from the 300 series to a charger style. If that helps 

[pfrederi 17,116]

1 minute ago, mark in ny said:

My pto currently on my electro is what ed posted in which it has a slot on the end that engagement arm slides into. My 312 has a hoop system how do I interchange the pto system I guess is my question coming from the 300 series to a charger style. If that helps 

  Se my edited post with picture

 

[mark in ny 27]

Perfect that's the answering I was looking and hoping for thank you

[Ed Kennell 35,581]

The PTO  bell with the slotted shaft on the Electro  should fit on the 312 engine that does not have the slotted shaft.

[mark in ny 27]

Ok next question. Glad I found this site big thank you to you guys. I know some years dont have a rectifier but I'm wondering if mine does or doesnt since it's been molested previously. I have 4 wires coming from the flywheel. Theres one ground to the condenser, then theres a plug with 3 wires the top one being the power to condenser which has all the safety switches allowing the condenser to energize. So that leaves me with 2 yellow wires from the flywheel on the bottom . Ripping out the dash I see one side that was black from the bottom where a yellow is was disconnected and the other goes to ignition. Typing this if I'm correct one went to the voltmeter which I believe charged the battery? Any thoughts? Wiring is such a pain especially since previous owners always mix and match colors.

[pfrederi 17,116]

What did you new 301 come from?? Spec Number???  if yoor new 301 really had battery ignition it could have had 3 amp unregulated system or a 15 amp regulated charging system. Each may have had  wires in the harness from the engine. A 3 amp system one wire was the feed for the coil, one for the charging system direct to the snitch and the third was for the head lights. If it was a real 15amp system 3 wires one to feed the coil two were AC to go to a regulator

[mark in ny 27]

[gwest_ca-(File Mod) 10,478]

The spec number 47828 was only used in 1986 on two 312-8 tractor models. 21-12K802 and 21-12K803 with the difference being the differential carrier bearings.

This engine has battery ignition and a 3 amp unregulated charging system so no regulator.

 

One of the stator wires goes directly to the headlamp switch for the lights. They will run on AC power and the higher the rpm the brighter the lights. The engine must run for the lamps to work.

 

The 2nd stator wire has a diode in it right at the connector that plugs into the tractor harness. You can feel the 3/16" diameter x 3/8" long diode in the tape that covers it. The diode rectifies the AC charge current producing the 3 amp DC current required to charge the battery. In theory the low charge current does not require a voltage regulator to protect the battery from overcharging but it does happen.

 

Garry

[mark in ny 27]

1 hour ago, gwest_ca said:

The spec number 47828 was only used in 1986 on two 312-8 tractor models. 21-12K802 and 21-12K803 with the difference being the differential carrier bearings.

This engine has battery ignition and a 3 amp unregulated charging system so no regulator.

 

One of the stator wires goes directly to the headlamp switch for the lights. They will run on AC power and the higher the rpm the brighter the lights. The engine must run for the lamps to work.

 

The 2nd stator wire has a diode in it right at the connector that plugs into the tractor harness. You can feel the 3/16" diameter x 3/8" long diode in the tape that covers it. The diode rectifies the AC charge current producing the 3 amp DC current required to charge the battery. In theory the low charge current does not require a voltage regulator to protect the battery from overcharging but it does happen.

 

Garry

Ok thanks, I peeled back the protective sheathing and found the diode. I guess the ac line I'll just cap and leave alone as the lights are off the battery with a fuse. Hopefully I have enough room I can clip the wire on the connector side of the diode and have enough room for a butt connector and then the swap is ready to happen 

[953 nut 51,480]

9 hours ago, mark in ny said:

I guess the ac line I'll just cap and leave alone as the lights are off the battery with a fuse.

If you never use the lights that will work. The 3 amp charging system will keep the battery charged and power your ignition. If you do plan to use the lights you should use them on AC or change over to LED lights.

[mark in ny 27]

Ok so got the motor swapped over and running nice and smooth maybe very minimal carb fine tuning as it pops in the exhaust maybe once every 15 seconds or so sometimes longer. So now the issue is belt size I must have over looked the drive pulley from the 312 is smaller than the original electro. Is it easier swapping to a smaller belt or swapping pulleys?

[953 nut 51,480]

The Electro was a hydro transmission and the 312 is manual. Easy enough to swap out the pulleys so your gear ratio is right and you can bolt on the PTO disk.