The Honda Aero 125 Thread

Discussion in 'Battle Scooters' started by RedArrow, Nov 14, 2013.

  1. gitsum79

    gitsum79 Adventurer

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    The enricher circuit is a small passage that adds extra fuel to make the fuel mixture richer for starting and running the engine before it warms up. A 12 volt current runs through the bystarter warming and melting a ball of wax that allows a spring to extend the plunger/needle closing the enricher circuit hole. Generally when the motor is warm the carb is warm too and the wax stays melted, so the bystarter plunger stays closed (extended) unless the engine cools down enough to solidify the wax again.

    If you follow the wires under the floorboard their should be a connector/plug somewhere.

    Closing the little enricher passage where the needle goes will effectively close the circuit disabling the bystarter. A dab of JB Weld or a drop of solder will work. You can take apart the bystarter and remove the needle and fasten the assembly back on the carb to keep dirt and contaminants sealed out.

    It is possible that the fuel mixture is too rich when the engine is warmed up because the enricher circuit stays open. But in my experiences the enricher circuit can add enough fuel to affect the overall carb tuning also, though most noticeable in the lower throttle settings.
    #61
  2. JerryH

    JerryH To Each Their Own Supporter

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    In that picture, the green and yellow wires go to the connector, which is that round black thing. It is rubber. You just grab a hold of it and pull it off, just like a spark plug wire. The bystarter is under it, and just screws into the carb body, again much like a spark plug. It can be replaced, or you can just leave it out and plug the hole, and leave the plug disconnected. Just zip tie it out of the way.

    I do not know exactly how a bystarter works. I have owned a number of scooters that had them, but never worked on them. My Stella, which is a copy of a vintage Vespa, still has a choke.

    The 2 screws on the front side of the carb are the idle speed adjustment screw, and the idle air screw. The one in the very center is just an idle speed adjuster. It adjusts how far the slide can close. The idle air screw, or pilot screw, is used to adjust the idle air/fuel mixture. The further out you turn it, the richer the mixture becomes. If you did not have this screw out, remove it and spray some carb cleaner in the hole. There is a tiny passage in there that can get plugged up. Then put the screw back, turn it all the way in till it seats lightly, and back it out about 2 turns. Final adjustment is best done with the engine idling if possible. There will be a spring behind the screw, and possibly a washer as well.


    I just checked the diagram, and those yellow and green wires do unplug on the other end. They have bullet style connectors on them, which means each wire has a connector. The connectors are probably covered in clear plastic. Unfortunately the bystarter assembly is no longer available from Honda. Oh, and it looks like there is a pinch type clamp, similar to what you would find on a fuel line holding the bystarter in place.
    #62
  3. DaBinChe

    DaBinChe Long timer

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    <object width="560" height="315"><param name="movie" value="//www.youtube.com/v/1uCWMmdNPDc?version=3&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="//www.youtube.com/v/1uCWMmdNPDc?version=3&amp;hl=en_US" type="application/x-shockwave-flash" width="560" height="315" allowscriptaccess="always" allowfullscreen="true"></embed></object>
    #63
  4. Wentwest

    Wentwest How's that work?

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    Don't go pulling on the bystarter wires. It's not like a sparkplug.

    If you plug up the circuit you have to plug up the jet hole and the air passage, and I used the inner cylinder and needle from a broken bystarter to do that. Before you do that follow the advice to follow the lines down and disconnect them, then remove the half circle clip that holds down the bystarter and then pull it out, gently. There are o-rings in there that you do not want to tear. If they leak air, lots of things don't work very well.

    One tell tale, besides running too rich when warm, is that adjusting the idle mixture screw does not seem to make much difference at all. If that's true, the bystarter is not closing off its circuit.
    #64
  5. RedArrow

    RedArrow With scootrboi

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    Again, I'm amazed and thankful for so many of you who stepped forward to share your knowledge in experience in all things bystarter.

    Bystarter. A month ago I'd never heard of the word. Now it's popping up in my dreams.

    I would have answered everyone sooner but I spent most of the day in the garage and it turned out to be quite interesting. Why? Because I learned something today, and any day I learn something is a good one, especially when it creeps up on you, taps you on the shoulder, and takes you by surprise. Probably the best kind of learning if you ask me, because those are the lessons that really stick. OK, enough prelude.

    After convincing myself that my idling problems were due to a bad bystarter, I was half ready to yank the darn thing and go manual. I mean, I'd never really tested it, mostly because that page in my shop manual looked intimidating when I couldn't even find the darn wires. But then I realized that that was because I'd never really looked for them. So I followed the wires where they disappeared under the floorboard and wouldn't you know it, they made a quick U-turn and then ran up to an easily-accessible junction cluster pretty much right over the carb. It couldn't have been easier. See what I mean?

    [​IMG]

    Feeling a bit embarrassed, I dove in. Pulling them apart was a snap (not literally:D).

    [​IMG]

    Here's my ohm reading. Specs say toss it out if it reads 10ohms or more. Looks OK to me, which at the time was disappointing. I wanted the bystarter to be as bad as I thought it was, and it wasn't cooperating.

    [​IMG]

    So, on to test two: Measure the needle and then hook it up to 12v. This is the before reading.

    [​IMG]

    And this is my Jed Clampett jumper set-up. Yes, those are paperclips. But it worked.

    [​IMG]

    So here's the reading about 5 minutes later. The bystarter was warm to the touch. I guess that hi-tech wax was doing its thing.

    [​IMG]

    Resistance dropped a bit, too.

    [​IMG]

    So after all that, I decided the clean the carb. Again. I thought I'd cleaned it good the first time, but after testing the bystarter I was suddenly forced to question my previous efforts. A tip of the mechanic's hat to those inmates who counseled a good carb cleaning the first time. You got this one right.:deal

    I'm happy to report that after reinstalling the carb, it started up and ran great. There was even an extra little scooter-type note in the engine idle that had been missing before. I couldn't be happier. I went three times around the neighborhood and it didn't stall out once. Now I can concentrate on learning to ride instead of worrying about stalling out at every stop. What a difference. I may still have to tweak the idle speed, but still, what a difference.

    And as a way of giving back, here's my Tip of the Week: Want to clean your carb parts but can't afford one of those fancy sonic cleaners? No problem! All you need is a little Yankee Know-How crossed with some Scottish tight-fistedness. See, a common electric razor is all you need:

    [​IMG]

    It really works!

    [​IMG]

    Oh, and thanks for posting the video of those kids. I expect to see them on the X Factor one of these days. Thanks again to everyone for your help. Next week I'm off to the DMV to take my written test so I can then get my M1 endorsement, along with changing my front tire between practice runs. It should be a fun week!

    ~ Tootles
    #65
  6. DaBinChe

    DaBinChe Long timer

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    It's a Honda all you gotta do is clean the carb and just ride!

    What's the cleaning solution you used? I had thought about doing the same but don't have an electric razor. Just recently finally got a sonic cleaner off amazon for $25.

    CA DMV M1 test is a breeze.

    Now all you got to do is:

    <object width="420" height="315"><param name="movie" value="//www.youtube.com/v/w_kIUSr7-is?version=3&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="//www.youtube.com/v/w_kIUSr7-is?version=3&amp;hl=en_US" type="application/x-shockwave-flash" width="420" height="315" allowscriptaccess="always" allowfullscreen="true"></embed></object>
    #66
  7. JerryH

    JerryH To Each Their Own Supporter

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    Glad you got it going. I never thought much of those sonic cleaners. I take the jets and put them in a glass jar with some carb cleaner, let them soak, shake them up, let them soak again, and then clean them with a wire (not just any wire, it has to be the small E string from a guitar. Don't use paperclips, pins, needles, or anything like that. They can damage the jets) I have seen jets so plugged up that no amount of sonic cleaning would have cleaned them. I've spent as much as half an hour gently working a guitar string through a jet that was plugged up with something as hard as metal. Probably corrosion from ethanol gas. I had to replace the main jet (and the float bowl) on a friends Honda generator. He had left gas in it for over a year. The gas evaporated, leaving just the ethanol, which rusted the steel float bowl and plugged up the main jet so badly they could not be saved. I've seen ethanol damage many times before, but I have to admit I was shocked when I removed that float bowl. It looked like it was full of rusted steel wool.
    #67
  8. Wentwest

    Wentwest How's that work?

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    We'll have you zipping around on that scoot in no time. Once the tuning and the cleaning and the tightening and the testing is done, and it runs great, I end up missing the challenge of solving some puzzling thing or other, and I start shopping for another sad, neglected Honda to bring back to life. There's just nothing like the joy of hearing that engine start running right.

    By the way, I've never seen a Honda scooter with the bystarter screwed in like that. On the bigger Elites it's clamped in. Same with the Gyro.
    #68
  9. RedArrow

    RedArrow With scootrboi

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    100% Sea Foam. Love the stuff. The first time I used some off the shelf aerosol carb cleaner. I think the Sea Foam actually did a better job. I hate "sacrificing" half a can to the soak tank because the stuff isn't cheap, but you can find it on sale if you look and the rewards using it this way are worth it.
    #69
  10. RedArrow

    RedArrow With scootrboi

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    My bf is an erstwhile musician so I bet we've got a a spare E string floating around here somewhere. That idle jet hole is really a tiny one!

    Do they add ethanol to all gasoline or is it just certain brands? Sounds like something that it would be a good idea to avoid.
    #70
  11. RedArrow

    RedArrow With scootrboi

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    I've got to admit that my overpowering emotion during this entire process has been more of one of frustration than of satisfaction. :D But I can see the possibilities. I guess another thing involved is me being rather busy in my life right now with other things and so the time I spend with my Honda would rather be spent riding than on some seemingly mysterious idle problem. If I was retired and could spend every day out in the garage, I think the situation would be different. But this whole carb thing is one challenge I won't mind looking back on.

    That said, I can see the satisfaction of bringing some under-appreciated and neglected bike back to life bolt by bolt. There is something deeply satisfying in that, certainly. Folks who don't work on bikes must get it from something else, but it seems to answer some basic human need to bring order out of chaos, or something like that.

    I think I need some more coffee....:D
    #71
  12. Wentwest

    Wentwest How's that work?

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    Don't you think that would be a great name for a pizza delivery company?

    Order From Chaos!

    I'll have a large mushroom and red onion please. Double anchovies for my noisy neighbor with the high blood pressure!

    And, just so you keep some perspective, remember that without that little red Aero you would never have met a bystarter or all the strangely helpful people you found here.

    And next time you feel a little hungry, Order from Chaos.
    #72
  13. DaBinChe

    DaBinChe Long timer

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    Ah yes sea foam that stuff works wonders. You can still reuse the stuff just pour it thru a few coffee filters and good as new. Actually after filter it pour it right into your Aero tank. I normally get it at wally world, sometimes I find it in a gallon can and it is cheaper that way.
    #73
  14. Chillis

    Chillis Long timer Supporter

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    That is a right proper find! "If the headlight's out just jiggle the cord".

    #74
  15. RedArrow

    RedArrow With scootrboi

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    Did someone say pizza? :D

    [​IMG]

    I was looking for some crazy Italian on a scooter delivering a pizza and wound up with this instead. The expression on the dog's face just cracks me up.
    #75
  16. DaBinChe

    DaBinChe Long timer

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    Just stopped by my friend's shop Battlescooter yesterday and picked up a few things and he had an Aero125 in the back and asked if I wanted to buy it. Said it ran like it was on roids, was missing a few things but looked good with over 10k miles.
    #76
    Wolfeboats likes this.
  17. RedArrow

    RedArrow With scootrboi

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    Gosh. That was really nice! Today was one of those days when someone brings you a motorcycling jacket with armor and a full faced helmet for free and that, combined with your words of encouragement have made this a very appreciative day indeed. Thanks.

    Tomorrow, I'm going to take her out on the street for the first time without worrying about her dying at every stop. I'm going to photograph her with all of her cladding back on (I still need to replace the seat) and continue to document my journey.

    This is my first bike; I don't have a motorcycle license; and I'm by no means an expert mechanic, but I grew up in the Volkswagen generation, and my dad taught me how to maintain a simple air-cooled engine. I guess those lessons stuck with me. I don't care if it's a sewing machine, a weed-whacker or a Honda scooter, these are things worth knowing and teaching your children like how to build a fire or cook their own food and in a way — survive.

    Sometimes with these old bikes, you've got to modify and not be afraid to modify and think creatively. Anyone can walk into a showroom, plop down some cash, and ride out with a perfectly running machine. But where's the fun in that? Short term vs. long term. Basically, will any mechanic care about your bike as much as you do?

    I want people to participate without feeling like I have all the answers, because I'm really new at this, too.
    #77
  18. RedArrow

    RedArrow With scootrboi

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    Sounds like an interesting deal. Are you going to buy it or what and what's missing? Is it a gold one or a red one? How about a picture?
    #78
  19. DaBinChe

    DaBinChe Long timer

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    No, I have no interest in it...already have my NHX110, Tomos Honda moped and a W650. So got more then I can ride at any given time. Reality is I want/need things that I rather spend more time riding then wrenching, cause I'd rather ride then wrench. The Aero is missing a front fender and needs the seat upholster, other then that it looked in really good shape, plastic was very nice..can't remember if it was red or gold. Look up Battlescooter.com and email'em and ask for pics. Tell'em the scooter riding crazy dog eating gook sent you. He said make him an offer, so make sure to low ball him first.
    #79
  20. RedArrow

    RedArrow With scootrboi

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    Hey, DaBinChe. Is this the place in Sunnyvale? I tried Googling Battlescooter but just got a bunch of Ruckus stuff with no link for used bikes. I'm not really interested in buying another one right now (although I kind of am :D) but would still like drooling over some pictures and you can always use another parts bike, right?

    At this point I'm with you — I want to ride rather than wrench, but all you inmates out there might want to check it out because these are great little scoots; and fast, too!

    You're the only guy I know who if the Domino's delivery dog came to your house, you'd eat the dog instead of the pizza. :rofl
    #80