Jump to content

1973 Yamaha AT3 wiring help


Claw
This post is 5917 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

Hello everyone,

I'm taking the chance of being kciked out since I'm not really working on a complete Yamaha bike. I have a project bike that I'm trying to get a Yamaha AT3 engine into. The bike used to be a '82 moped but the motor was so finicky, and only 50cc, I decided to upgrade. I found a guy who sold me a "ran when I parked it" AT3 motor, parts AT2 motor, and a bucket of bits. I"ve found that the AT2 motor needs a new piston and head, a new oil pump cover, and the cover over the dynamo but otherwise is all there. The AT3 motor is complete and in decent shape from the bottom through the head with everything but the dynamo cover. The bucket of bits had a good looking exhaust, though I don't think it is for the AT3, not sure on the AT2, two carbs without the top/slide, what I believe to be a voltage regulator, and again what I believe to be a starter relay. I have a spare ignition coil from a friend and the small (primary?) wire reads about 2 ohms and the large (secondary?) wire reads about 13 K ohms when measured to the ground on the bracket.

My problems are these; I'm not a motorcycle mechanic first and foremost as you can probably tell at this point. I've never worked on motorcycles and wanted to get this running to learn/test on and maybe be a good cruiser around town or up in the paved canyon roads. I think I can get the actual mechanical alignment right, and it seems to be able to shift gears and the kick start cycles the piston. I also have a carb from a Suzuki TC120, so it is a little smaller but is complete and free, that might work as soon as I make an adapter plate. But how can I rig this wiring up? I have a wiring diagram, but I'm hoping to ignore the flashers for now (especially since I don't have the flasher circuit) and just keep with getting it running, a headlight, and a tail/brake light. I know I don't have the main switch but would be fine with push button and toggle switches for anything that requires it (starter?).

If someone with more knowledge can help me with a step by step system to take the motor, wire everything necessary, and then ride off into the sunset I would really appreciate it. Let me know what info would be useful since I'm not even sure of that.

Thanks again!

Claw

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.

Hello everyone,

I'm taking the chance of being kciked out since I'm not really working on a complete Yamaha bike. I have a project bike that I'm trying to get a Yamaha AT3 engine into. The bike used to be a '82 moped but the motor was so finicky, and only 50cc, I decided to upgrade. I found a guy who sold me a "ran when I parked it" AT3 motor, parts AT2 motor, and a bucket of bits. I"ve found that the AT2 motor needs a new piston and head, a new oil pump cover, and the cover over the dynamo but otherwise is all there. The AT3 motor is complete and in decent shape from the bottom through the head with everything but the dynamo cover. The bucket of bits had a good looking exhaust, though I don't think it is for the AT3, not sure on the AT2, two carbs without the top/slide, what I believe to be a voltage regulator, and again what I believe to be a starter relay. I have a spare ignition coil from a friend and the small (primary?) wire reads about 2 ohms and the large (secondary?) wire reads about 13 K ohms when measured to the ground on the bracket.

My problems are these; I'm not a motorcycle mechanic first and foremost as you can probably tell at this point. I've never worked on motorcycles and wanted to get this running to learn/test on and maybe be a good cruiser around town or up in the paved canyon roads. I think I can get the actual mechanical alignment right, and it seems to be able to shift gears and the kick start cycles the piston. I also have a carb from a Suzuki TC120, so it is a little smaller but is complete and free, that might work as soon as I make an adapter plate. But how can I rig this wiring up? I have a wiring diagram, but I'm hoping to ignore the flashers for now (especially since I don't have the flasher circuit) and just keep with getting it running, a headlight, and a tail/brake light. I know I don't have the main switch but would be fine with push button and toggle switches for anything that requires it (starter?).

If someone with more knowledge can help me with a step by step system to take the motor, wire everything necessary, and then ride off into the sunset I would really appreciate it. Let me know what info would be useful since I'm not even sure of that.

Thanks again!

Claw

Link to comment
Share on other sites

If you really want to do this I would suggest you buy a parts bike and use the wiring harness, voltage regulator,ingnition coil,stop switch ect....... and you must have a 12 volt battery for this engine to even run. The at series enduro's are 12volt to power the electric starter.

Link to comment
Share on other sites

If you really want to do this I would suggest you buy a parts bike and use the wiring harness, voltage regulator,ingnition coil,stop switch ect....... and you must have a 12 volt battery for this engine to even run. The at series enduro's are 12volt to power the electric starter.

The AT2 I have in bits is 6 volt and has no electric start ... big differences between AT2/3 and AT2/3E

Link to comment
Share on other sites

The AT2 I have in bits is 6 volt and has no electric start ... big differences between AT2/3 and AT2/3E

I can only speak of the US models.

Link to comment
Share on other sites

Hello everyone,

I'm taking the chance of being kciked out since I'm not really working on a complete Yamaha bike. I have a project bike that I'm trying to get a Yamaha AT3 engine into. The bike used to be a '82 moped but the motor was so finicky, and only 50cc, I decided to upgrade. I found a guy who sold me a "ran when I parked it" AT3 motor, parts AT2 motor, and a bucket of bits. I"ve found that the AT2 motor needs a new piston and head, a new oil pump cover, and the cover over the dynamo but otherwise is all there. The AT3 motor is complete and in decent shape from the bottom through the head with everything but the dynamo cover. The bucket of bits had a good looking exhaust, though I don't think it is for the AT3, not sure on the AT2, two carbs without the top/slide, what I believe to be a voltage regulator, and again what I believe to be a starter relay. I have a spare ignition coil from a friend and the small (primary?) wire reads about 2 ohms and the large (secondary?) wire reads about 13 K ohms when measured to the ground on the bracket.

My problems are these; I'm not a motorcycle mechanic first and foremost as you can probably tell at this point. I've never worked on motorcycles and wanted to get this running to learn/test on and maybe be a good cruiser around town or up in the paved canyon roads. I think I can get the actual mechanical alignment right, and it seems to be able to shift gears and the kick start cycles the piston. I also have a carb from a Suzuki TC120, so it is a little smaller but is complete and free, that might work as soon as I make an adapter plate. But how can I rig this wiring up? I have a wiring diagram, but I'm hoping to ignore the flashers for now (especially since I don't have the flasher circuit) and just keep with getting it running, a headlight, and a tail/brake light. I know I don't have the main switch but would be fine with push button and toggle switches for anything that requires it (starter?).

If someone with more knowledge can help me with a step by step system to take the motor, wire everything necessary, and then ride off into the sunset I would really appreciate it. Let me know what info would be useful since I'm not even sure of that.

Thanks again!

Claw

do we know wether this is a 6 or 12 volt motor you have ?

Link to comment
Share on other sites

  • Who's Online (See full list)

    • There are no registered users currently online
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...