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Bystarter FAQ Question
Posted: Wed Nov 08, 2006 10:34 pm
by Skullet
i am just curious since this isnt really explained. the link below is to the tech doc about rebuilding a bystarter. i want to try this, but is this something that can be done to FIX the bystarter, or is it just for if you accidentally or for some other reason took it apart? im thinkin maybe thats why mine wont idle, but i have no idea.. i took out the little vacuum box or whatever it is and tore that apart, the filter inside was so old it was crumbling, so i replaced it with a quad layer of shop towels.. lol... still nothin.. checked the fuel and return lines, everything seems fine there... so its gotta be either this or the timing.
http://www.hondaspree.net/phpBB/viewtopic.php?t=1504
Posted: Sat Nov 11, 2006 12:26 pm
by JF
...or is it just for if you accidentally or for some other reason took it apart?
You pegged it with that statement above, although I did mention in that same article that you can test the bystarter by touching the two wires(yellow to positive, green to negative)to the terminals on the spree's battery. I would first try that and see if the needle moves out over the course of a few minutes. If it moves and/or you are still having engine trouble, then I would explore other possible causes. But, if it does not move after you have had it hooked up to the battery for at least 5-10 minutes, then the bystarter may have faulty wiring. I am considering posting a how-to on repairing faulty bystarter wires, but I'll need to take my bystarter apart again in order to do that.
I would also suggest you get a honda replacement foam filter as soon as you can, because shop towels are probably not going to help the diagnosis process. You can usually get the foam from ebay, Honda, or certain power sports dealers. An aftermarket pod filter is another option you could consider, but keep in mind that a larger main jet is usually nessesary in order for the air/fuel ratio to be correct.
Let me know if the bystarter works or not, and then we can go from there.
Good luck,
JF
Posted: Sun Nov 12, 2006 12:04 am
by vonchuk
These scooters are extremely sensitive to how the intake is set up. I would definitely get the proper air filter element (Mine was $3.00 at honda) and make sure the air cleaner itself has no leaks and the lid fits on tight. This is a common source of idling problems and flat spots or bogs at mid range and loss of top speed. So make sure this area is like it should be before trying any diagnostics. Changes in this area need a corresponding change in the main jet size. What does the bystarter do? All engines when cold need a slightly richer mixture to start. When cold the by starter withdraws a needle from an additional port allowing more fuel into the carb during starting. After the engine starts and runs for a minute the bystarter closes the port and and the engine then runs on the fuel from either the idle port or the main jet. If the scooter starts and idles for a little and dies when the bystarter closes its port then the idle jet is plugged assuming the idle speed is set right. If it idles put quits when you open the throttle then the main jet is plugged or you have a leak at the air cleaner. Chuk
Posted: Sun Nov 12, 2006 4:06 am
by Skullet
the filter i was talkin about is a little crappy foam thing inside the vacuum canister or whatever it is that i took apart. its mounted under the seat behind the frame, and it has a line goin to the head and another to the airbox, and theres a plugged line comin off the bottom of it that goes nowhere. the filter inside that thing was fallin apart, so i just threw some pieces of clean shop towel inside it. i know my air filter is kinda dirty-ish, but didnt think thatd affect it too much since my old aero80 ran open tb just fine. wrong? i saw the thing about testing the bystarter as well, but didnt want to cut into the wires to test it. sounds like i might have to tho. 
Posted: Sun Nov 12, 2006 1:27 pm
by JF
i saw the thing about testing the bystarter as well, but didnt want to cut into the wires to test it.
Really all that is necessary is to unscrew the bystarter from the carburetor, and disconnect the two push-in style connectors. No cutting or modification should be required, although sometimes you may have to disconnect the carb from the intake manifold in order to completely remove the bystarter. If you could take a picture of the carb/airbox assembly then we might be able to help you further with the engine diagnosis.
Also, have you gotten around to cleaning the carb yet? If not, then you may want to do that when you take it off to check the bystarter. If the filter foam in the airbox was as bad as you said it was, then it is likely that some junk got clogged up in the carburetor, thereby making the engine run bad...or not at all.
If you need links to websites that have replacement filter foam, or need further assistance when you go working on the engine, let us know.
JF
Posted: Mon Nov 13, 2006 12:41 am
by Skullet
ive already had the carb off and completely tore apart and dipped in carb cleaner for bout 3-4 hours... the air filter isnt bad, its just not perfect. ill have to give my local honda a call tomorrow and see how much one is. i will also get out the digicam and take some hi-res pics of the stuff im talkin about.