Jstrand 18 #1 Posted April 20, 2022 Hello big newbie here, I have a 1960 550 Suburban Wheel Horse from my Grandpa that I'm trying to get all fixed up. It runs but the wiring was all taken a part and would like to get a schematic regarding the wiring of the tractor. I feel as though I will be starting from scratch but there are still wires connected in some spots that I need to sort out. Any help is much appreciated! 1 Share this post Link to post Share on other sites
wallfish 15,932 #2 Posted April 20, 2022 I don't know if there even is a wiring schematic for those old 550 tractors. There's not much to them anyway so I'm sure we can help you along. Post up some pics of what's there now so we have an idea of what's going on and if all the parts with wires or supposed to have wires are there. The 550 is the same exact tractor as the pullstart 400 with a Kohler K91 except for the electrical start stuff. Is the engine on there a Lauson H55? Not too many of those engines left as they gave up the ghost and replaced with other engines. Share this post Link to post Share on other sites
WHNJ701 4,164 #3 Posted April 20, 2022 I like my lauson h55. Like in other posts I removed all the electronics and just use the pull start. It's a reliable engine and easy to start. The lauson electrical parts are expensive and hard to get any more Share this post Link to post Share on other sites
953 nut 51,737 #4 Posted April 20, 2022 Your engine has a magnito so there is no electrical connection to the ignition system. Someone who ownes one may be able to add a picture of the 551 Ignition shut off system consists of a wire from the (choke handle I think) that will contact the top of the spark plug to short it to ground. Here is a drawing of the electrical system. There are two diodes and a fuse in the item labled rectifier, don't get them mixed up. Wires 3991, 3993 and 3662 will be six guage wires. All other wires can be sixteen guage. 2 Share this post Link to post Share on other sites
formariz 11,850 #5 Posted April 21, 2022 Before you start tinkering with the electrical part of that engine, study the attached information. That engine's electronics is a bit unconventional. Many engines have been rendered useless by unaware owners. Parts for it are as hard to find as hen's teeth. Switch and solenoid are unique to that engine, and operated through grounds and not power. 2 Share this post Link to post Share on other sites