Solex 27 #1 Posted March 4, 2015 I recently acquired a Magnum 12 engine that I would like to install in my Wheel Horse 308-8. The current 8 HP engine runs great, but more power is always difficult to resist. My question is regarding using the current 308-8 wiring harness with the Magnum 12. In addition to the starter, what additional wires do I need to make the engine run. The 12 has an additional low engine oil connector, the 8 only has a single connector comming from the engine with no low oil feature. Share this post Link to post Share on other sites
Fordiesel69 214 #2 Posted March 4, 2015 You do not need all those extra wires. That wire is used to ground the coil, which cuts the engien. Share this post Link to post Share on other sites
rmaynard 14,909 #3 Posted March 4, 2015 (edited) By no means apply any voltage to that wire. You will damage the magneto if you do. Edited March 4, 2015 by rmaynard Share this post Link to post Share on other sites
Solex 27 #4 Posted March 4, 2015 Appreciate the information,so that I am clear, the 12HP has two connectors on the engine. The low oil is a 5 position with 3 White and 1 purple wire, one position is blank. One of the white wires goes to the coil or ignition module and that should not be connected correct? The second connector on the 12HP is a three position with two white and one brown wire. The three position connector on the 308-8 wiring harnes is 2 Black 1 White and is not plug compatible with the three position connector on the 12HP. Therefore these wires will need to be spliced or a jumper cable made to go between them. My question is what 3 wires from the 308-8 harness go with what 3 wires from the 12 HP engine? Share this post Link to post Share on other sites
Don1977 604 #5 Posted March 4, 2015 The question no one has ask is did the 12 HP Magnum come off a Wheel Horse. Share this post Link to post Share on other sites
WH nut 553 #6 Posted March 5, 2015 (edited) You need to pull up a wire diagram for the 2 and have a look. The magnum will run with no wires hocked up. It has a magneto for ignition and is grounded to kill the motor. The charging wires and the kill wire is the only wires you need to worry about. You will also need to change the ignition switch to a magneto switch Edited March 5, 2015 by WH nut 2 Share this post Link to post Share on other sites
Solex 27 #7 Posted March 5, 2015 Thanks again, this Engineis from a Wheelhorse 312-8. I can also compare where the wires come from on the 8Hp and the 12Hp engine on three position connector. Then try and match to the wing harness. The wiring harness drawing in the owners manual does not give enough detail in terms of wire color going to the 3 position connector. I have not noticed if a Magnum drawing provides this information? Share this post Link to post Share on other sites
