can the bystarter be altered safely?

[olderguy]

I'm a newby, so please have patience with the question. Recently bought our first '85 Honda Aero 50. Owner's manual says NB50M. Runs excellent when warmed up, but refuses to start cold unless starting fluid is minutely used. Have read this is not a good idea. Found this site on the internet, and have read much on the subject of cold starting. Most references say to check the bystarter among other things. Have checked the bystarter and this seems to be the problem. Question is... somewhere (not sure where) I read of someone who removed the barrel and needle from the bystarter and adjusted the carburetor to make the machine run a little more lean to compensate. When I got the '50 I also got a parts bike. Since both bystarters test as defective, I thought I'd remove the parts as suggested and try it. Had instant results!! The machine starts up immediately when it is cold and seems to idle fine. Haven't tried to take it out yet. Question is... can I adjust the carb to run more lean? If so, how. Also, am very open to experienced people helping me in this matter. Will this hurt the machine? Thanks!

[Wheelman-111]

Greetings:

It'd be just about impossible to predict how to adjust or re-jet a stock carb so that the Bystarter circuit remains engaged. The carb can feed the engine mixture suited to cold running or warm running, but not both. If it could do that, you wouldn't need a bystarter.

I suggest you contact USPmale on this forum or go online for a good used carb and/or bystarter and put it back to stock. It actually runs quite well when everything is functional.

Good luck!

[olderguy]

Thanks so much for the reply. I'll look into keeping things stock as advised. Just read the information given on this site regarding bystarters, and it was very helpful in understanding the function of the thing. Great communication of what is going on when the bystarter is functioning properly.

[mookie]

here is what i learned and was told by a competent mechanic-
the bystarter can be shimmed up to regain its effectiveness, which is to say it will raise up enough to open the choke circuit since its job is to extend into the cavity.
this may be the reason the scooter wont start when cold.

try this- remove the two screws holding the bystarter/retaining half ring to the carb body. place a thin washer under each side of the retaining ring thus holding the bystarter slightly up and off the carb body. not much just a scoshe.

see if it starts cold. nothing ventured, nothing gained.
i've done this on a few carbs and on some it helped and some it didn't. i wish it were rocket science but it isn't.

[Shelton]

How would you go about " testing " a bystarter to make sure it is working correctly ?

Trae

[olderguy]

Great news concerning my starting problem on the 85 Aero 50!! Took to heart the advice to keep it original and revisited the bystander situation. Read some more in various places on this site concerning carburetor and bystander testing/cleaning procedures. Found out I wasn't allowing enough time for the bystander to respond when hooked up to the battery. Seems to take a while for an "erection" to occur. Got an erection. Found an excellent post with pictures regarding cleaning a very small opening in the carb with a wire from a guitar. Found out this opening was plugged solid. Cleaned it, cleaned the rest of the carb as well while I was at it. Put in a new plug. Put everything back together, and it is working GREAT. Starts up cold within a few revolutions. When I say cold I mean cold. I live in Bend, OR and it has been minus 10 the last few nights. It is just above freezing in our garage where I've been working on this rig. Can't help but believe it will work great in the summer. Ran across a post regarding changing the motor to have a kick start. That will be the next project, though probably not until spring.

Thanks for all the help and ideas both from previous posts, and the instant response today. It truly is appreciated. I'm actually not a mechanic though I'm enjoying the project.

[Shelton]

Can someone post the link to the carb cleaning post ?

I have cleaned all of my carbs and it seems that sometimes they work after only one cleaning and sometimes it takes several cleanings

Thanks , Trae

[mookie]

that is really good news. i felt your exuberance with every word i read.
maniy love it when a plan comes together!

now what...? what's next for the little bugger?

[bradthreee]

Great news concerning my starting problem on the 85 Aero 50!! Took to heart the advice to keep it original and revisited the bystander situation. Read some more in various places on this site concerning carburetor and bystander testing/cleaning procedures. Found out I wasn't allowing enough time for the bystander to respond when hooked up to the battery. Seems to take a while for an "erection" to occur. Got an erection. Found an excellent post with pictures regarding cleaning a very small opening in the carb with a wire from a guitar. Found out this opening was plugged solid. Cleaned it, cleaned the rest of the carb as well while I was at it. Put in a new plug. Put everything back together, and it is working GREAT. Starts up cold within a few revolutions. When I say cold I mean cold. I live in Bend, OR and it has been minus 10 the last few nights. It is just above freezing in our garage where I've been working on this rig. Can't help but believe it will work great in the summer. Ran across a post regarding changing the motor to have a kick start. That will be the next project, though probably not until spring.

Thanks for all the help and ideas both from previous posts, and the instant response today. It truly is appreciated. I'm actually not a mechanic though I'm enjoying the project.

[mookie]

Well You Know Meehan...
wait...
it's coming...

...


.....



.......

HAD A HAND IN THIS!!!!!

[olderguy]

Trae,

Just read the note asking about testing the bystander. I'll share what my brain picked up, and if I'm incorrect I'll gladly accept someone else posting something contrary. Several sites say there are two ways to quickly test the bystander.

Test no. 1 is possible with the bystander still installed. Disconnect the leads of the bystander from the wiring harness. Using an ohm meter test the resistance of the bystander. You should get a reading of less than 10. However, you should definitely get a reading, as you are also testing for continuity. If you get a reading of 0, don't assume that because you got a reading of under 10 the bystander is good. If there is no reading at all it means the circuit has a failure in it and the bystander will not work.

Test no. 2 requires removal of the bystander from the carb. This can be done with the carb in place if you are careful to retain control over the screws holding it in position. Upon removal of the bystander place the green wire on the - side of the battery, and the yellow wire on the + side of the battery. Hold these wires in place for an extended period of time manually, or simply clip them to the battery terminals and walk away for a bit. In time the barrel/needle of the bystander will SLOWLY change position.

Here is why it will slowly change position. I incorrectly assumed at first the bystander was a solenoid and the change would happen immediately. As a result, when I touched the leads to the battery and did not get an instant result, I thought the bystander was defective. In reality the bystander is a heat-actuated fuel shut off. Picture the bystander as it is installed in the carb. The default setting of the bystander will have the barrel/needle raised up in the cavity provided in the carb for them. This allows a small amount of fuel to enter a cavity to prime the carb when it is cold. After the engine is started the electrical system sends current to the small heater in the bystander. This softens a substance in the bystander allowing the barrel/needle to become lowered in the cavity, shutting off the extra fuel no longer needed for starting purposes.

This change in the bystander is called an erection. Simply look at the bystander cold before attaching it to the battery and notice the relationship of the barrel/needle to the rest of the assembly. After a period of time if the bystander is working properly there will be a small, but noticeable, change in position. The barrel/needle of the bystander will extend from the assembly by about 5 mm. The bystander does not have to be in an upright position for this to happen. I simply placed it on it's side when it was connected to the battery and observed it.

As to the carb cleaning, if your carb has the VERY small brass orifice in the side of the float bowl you definitely don't want to miss cleaning it.

Hope this helped,
Oldguy

[olderguy]

To answer the question of what is next. I hope to alter the engine to have a kick starter. Why in the world they ever made this engine without one is beyond me.

[mash]

Hello, I don't mean to jump start this post..but, can anyone steer me in the direction on a good "Tested" carb and bystarter for a 1984 Aero 50, I got one off ebay but it is for a 1985 unit they are not the same at all Honda changed the Aero in 1985, so most engine parts for 1983 and 1984 will not work!?
Thanks In advance for your help
Mike

[Wheelman-111]

Greetings:

Some (including me....) that Honda-san got the styling just right with his original Aero, but the '84 and '85-later Aeros are very different critters. Even bore/stroke dimensions are different. Few (if any?) parts interchange, and Forum knowledge is scant. You could contribute to it. For example: What is the engine code "AF-?" stamped on your transmission cover?