Bystarter
Moderator: Moderator
Bystarter
I believe my bystarter may be faulty or the wrong version. I did the 12V for 10min test and it did move about an 1/8". However, my question deals with the default length. Can I get some comparitive numbers? Is there a length specification somewhere?
-I measured from the end of the needle to the round flat of the rubber housing. Cold = 0.82"
-Measuring from where it the needle looks to be sealing to the rubber housing = 0.63"
Here's my problem. My 1984 NQ50 will not start with the bystarter fully seated. If I plug the bystarter hole or place a spacer under the bystarter...walla, the scooter starts right up and runs great. This leads me to believe the bystarter is too long to begin with and is closing off the circuit. Anybody ever had this problem or knows how long the bystarter should be cold? Are all bystarters the same? I can't find a model number..
-I measured from the end of the needle to the round flat of the rubber housing. Cold = 0.82"
-Measuring from where it the needle looks to be sealing to the rubber housing = 0.63"
Here's my problem. My 1984 NQ50 will not start with the bystarter fully seated. If I plug the bystarter hole or place a spacer under the bystarter...walla, the scooter starts right up and runs great. This leads me to believe the bystarter is too long to begin with and is closing off the circuit. Anybody ever had this problem or knows how long the bystarter should be cold? Are all bystarters the same? I can't find a model number..
- bradthreee
- Board Supporter

- Posts: 1922
- Joined: Tue Sep 12, 2006 4:20 pm
- Location: MARS...
Most bystarters are the same, the only difference being the connectors. Either 2 bullet connectors or one plastic plug.
I remember seeing different groves on the bystarter housing that possibly allows you to adjust the depth you would like the bystarter to enter into the carb housing.
Check that out
I remember seeing different groves on the bystarter housing that possibly allows you to adjust the depth you would like the bystarter to enter into the carb housing.
Check that out
Bystarter
Looking at the bystarter a little more I've noticed the black 2-piece housing portion is threaded. Unscrewing it will adjust the default (cold) needle length. Was this inteded as an adjustment feature? Any reason this won't work?
The other thing I thought of was the Bystarter jet inside the carb. I recently cleaned the carbs, is it possible the jet isn't fully re-seated causing the circuit to close?
The other thing I thought of was the Bystarter jet inside the carb. I recently cleaned the carbs, is it possible the jet isn't fully re-seated causing the circuit to close?
- bradthreee
- Board Supporter

- Posts: 1922
- Joined: Tue Sep 12, 2006 4:20 pm
- Location: MARS...
-
mousewheels
- Veteran OG

- Posts: 3487
- Joined: Tue May 22, 2007 8:10 pm
- Location: North of Seattle, WA
Yours may be different, but I have only a single grove for the "U" shaped retainer ring. Lower grove is for an "O" ring to seal the bystarter to carb joint.I meant there are notches on the bystarter that may allow you to adjust placement on the top of the carb by that u shaped brass piece that holds the bystarter in by 2 screws.
There's some nice pics in the tech docs section at the below link:
I note there's no comment in that doc re-assembly point to set to a specific length.
http://www.hondaspree.net/phpBB2/viewtopic.php?t=1504
- Wheelman-111
- Moderator

- Posts: 10683
- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
I Think It Moved: Bystarter *
Greetings:
History of this particular bystarter? Did it come with the bike or another source?
Honda bystarters may all be the same - dunno. But with all the other brands and their Asian knock-offs I can't believe they're all dimensionally identical.
I agree with Mousewheels - you're supposed to screw the plunger part all the way in. Anyway yours sounds like it's too long, if anything. Perhaps something is preventing you from getting it screwed in all the way down? I don't recall the specifics, but I believe mine moved a lot more than 1/8-inch in full "erection". Maybe it's not retracting all the way when cold? The plastic bit that holds the brass can break when it's pulled out of a gummy carb.
May I also suggest you measure the depth of the bystarter well cavity? If it appears shallower than the bystarter's cold length, you have your answer.
History of this particular bystarter? Did it come with the bike or another source?
Honda bystarters may all be the same - dunno. But with all the other brands and their Asian knock-offs I can't believe they're all dimensionally identical.
I agree with Mousewheels - you're supposed to screw the plunger part all the way in. Anyway yours sounds like it's too long, if anything. Perhaps something is preventing you from getting it screwed in all the way down? I don't recall the specifics, but I believe mine moved a lot more than 1/8-inch in full "erection". Maybe it's not retracting all the way when cold? The plastic bit that holds the brass can break when it's pulled out of a gummy carb.
May I also suggest you measure the depth of the bystarter well cavity? If it appears shallower than the bystarter's cold length, you have your answer.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Bystarter
How is the bystarter supposed to be installed? Is the metal ring supposed to fit inside the groove above the o-ring? If yes, the o-ring doesn't seal against anything? (see photo 3). I've always pushed the by starter in as far as it will go (photo 1), but the the bike won't start unless I unscrew the bystarter a little to modify the needles default length. It makes sense that the metal retainer should fit in the groove, but the o-ring seems useless then...?
What am i missing?


What am i missing?


- Wheelman-111
- Moderator

- Posts: 10683
- Joined: Wed Oct 22, 2008 5:09 pm
- Location: Deepinnaharta, Texas
Bystarter Blues
Greetings:
It's a bit hard to tell from the photos, but that BS does not look like it's correctly assembled and/or mismatched in its parts. I see some threads below the upper housing that should not be visible. The whole thing looks a little crossways, too. It may also be too big for that carb. The o-ring seals to the carb well on mine - it goes down all the way in. Has yours always lived on this bike?
There's an excellent review of bystarter disassembly in the Technical section with very good pics and an explanation to help you. I'll post it up if I stumble upon it.
It's a bit hard to tell from the photos, but that BS does not look like it's correctly assembled and/or mismatched in its parts. I see some threads below the upper housing that should not be visible. The whole thing looks a little crossways, too. It may also be too big for that carb. The o-ring seals to the carb well on mine - it goes down all the way in. Has yours always lived on this bike?
There's an excellent review of bystarter disassembly in the Technical section with very good pics and an explanation to help you. I'll post it up if I stumble upon it.
Wheelman-111
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
Most of my money is spent on scooterparts. The rest is just wasted.
"ISO": '03 Vespa ET4 Malossi187 74MPH
Flash 9: 2001 Elite SR Contesta 72 ZX Tran, 9:1 Gears, Stock Airbox/Carb/Pipe 58.8 MPH
Punkin: 2010 Vespa/Malossi S78, 61MPH
hello, I have been fooling with the bystarter on my 84 Aero 50 and its way differant from what you have here, It skrews in to the body of the carb. I bought a bystater on ebay from wincycles, but it is like the one you have here. I tok them both apart and the iner workings are about the same, I did not see any adjustments on either one. looks like they are all puttogether the same internaly. alos any one have a suggestion on getting a bystarter for my 84??? she only runns when I use starter fluid in the carb throat, but once started that way will run great?
Mike
Mike
Aero 50 1984
Yamaha 650 Custom 2009
Yamaha 650 Custom 2009
Bystarter
The pictures should expand larger in a new window if you click on them. I'll try to make them more clear tonight. The bs in the pictures has been unscrewed a bit, because it reduced the default length of the needle which allows the bike to start. I am the only owner of the bike so the bs is the original equipment. I am just confused on the groove above the o-ring. What's it's purpose? If it is used with the metal ring to secure it to the carb the o-ring definitly does not seal to anything?
-
mousewheels
- Veteran OG

- Posts: 3487
- Joined: Tue May 22, 2007 8:10 pm
- Location: North of Seattle, WA
The o-ring is at the bottom. It is a seal between the bystarter body to the bore of the well in the carb.I am just confused on the groove above the o-ring. What's it's purpose? If it is used with the metal ring to secure it to the carb the o-ring definitly does not seal to anything?
The metal ring goes on the top groove as a retainer.
