Honda Aero 125

[Slickolddude]

I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

[vex]

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

I recently acquired two of these myself. (Yes, this is an intro to the
newsgroup. "Hi, I'm a scooter owner")

The cold start problem is possibly related to a plugged pilot jet, or the
cold start enrichening circuit. This electrical part (that plugs into the
carb) is a known weak point in the fuel system. I think it's called the
autobystarter.
If I was going to guess, that's where I would start. I found some resources
on the 'net that contained resistance specs for the part, and a testing
procedure, but can't find them at the moment. A few minutes with google
should bring you good results. Try "nh125" or "honda lead", or "honda areo"
or "aero 125".






--Brett

[Slickolddude]

Post by vex

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

I recently acquired two of these myself. (Yes, this is an intro to the
newsgroup. "Hi, I'm a scooter owner")
The cold start problem is possibly related to a plugged pilot jet, or the
cold start enrichening circuit. This electrical part (that plugs into the
carb) is a known weak point in the fuel system. I think it's called the
autobystarter.
If I was going to guess, that's where I would start. I found some resources
on the 'net that contained resistance specs for the part, and a testing
procedure, but can't find them at the moment. A few minutes with google
should bring you good results. Try "nh125" or "honda lead", or "honda areo"
or "aero 125".
--Brett

Thanks I appreciate the help.

[SoCalMike]

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

i think thats the end of the era for honda 2-stroke scooters. last year,
last model. leaky seals? bad choke? dirty carb?

[Steve Burgess]

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

I recently bought an 84 Aero 80, same problem....
720km's on it... let me know how you make out
maybe we can help each other with any findings :-)

[TomJ]

Post by Steve Burgess

Post by Slickolddude
Anyone have and ideas or
fixes for the cold start problems?

I recently bought an 84 Aero 80, same problem....
720km's on it... let me know how you make out
maybe we can help each other with any findings :-)

First of all, the Aero 125 and Aero 80 use entirely different
cold-start systems. The 125 has an "autobystarter" (black plastic gizmo
on the top of the carb) that's electrically heated and bypasses the
cold-start section of the carb after a few minutes. It's similar to the
one on the Aero 50, but I don't know if ther're interchangeable. The
Aero 80 has a "control box" mounted on the engine shroud that's
connected to the carb via vacuum lines. It bypasses the cold-start
section of the carb when the cylinder gets hot enough.

In either case, the most likely problem is simply a dirty carb. Take
the carb out and clean it thoroughly. And then clean it *again*. ;)
Make sure you can blow compressed air through all the little holes. I
had the same problem on my abused Aero 80 when I got it. Took me three
tries to get it right, but after that it's always fired right up.

By the way, if either of you are in N. California and ever want to
sell, let me know, I'd love to get a 125 or a second 80.

-- Tom Jupille

-- Tom Jupille

[Slickolddude]

Post by TomJ

Post by Steve Burgess

Post by Slickolddude
Anyone have and ideas or
fixes for the cold start problems?

I recently bought an 84 Aero 80, same problem....
720km's on it... let me know how you make out
maybe we can help each other with any findings :-)

First of all, the Aero 125 and Aero 80 use entirely different
cold-start systems. The 125 has an "autobystarter" (black plastic gizmo
on the top of the carb) that's electrically heated and bypasses the
cold-start section of the carb after a few minutes. It's similar to the
one on the Aero 50, but I don't know if ther're interchangeable. The
Aero 80 has a "control box" mounted on the engine shroud that's
connected to the carb via vacuum lines. It bypasses the cold-start
section of the carb when the cylinder gets hot enough.
In either case, the most likely problem is simply a dirty carb. Take
the carb out and clean it thoroughly. And then clean it *again*. ;)
Make sure you can blow compressed air through all the little holes. I
had the same problem on my abused Aero 80 when I got it. Took me three
tries to get it right, but after that it's always fired right up.
By the way, if either of you are in N. California and ever want to
sell, let me know, I'd love to get a 125 or a second 80.
-- Tom Jupille
-- Tom Ju

Thanks Tom

[Steve Burgess]

Post by TomJ

Post by Steve Burgess

Post by Slickolddude
Anyone have and ideas or
fixes for the cold start problems?

I recently bought an 84 Aero 80, same problem....
720km's on it... let me know how you make out
maybe we can help each other with any findings :-)

First of all, the Aero 125 and Aero 80 use entirely different
cold-start systems. The 125 has an "autobystarter" (black plastic gizmo
on the top of the carb) that's electrically heated and bypasses the
cold-start section of the carb after a few minutes. It's similar to the
one on the Aero 50, but I don't know if ther're interchangeable. The
Aero 80 has a "control box" mounted on the engine shroud that's
connected to the carb via vacuum lines. It bypasses the cold-start
section of the carb when the cylinder gets hot enough.
In either case, the most likely problem is simply a dirty carb. Take
the carb out and clean it thoroughly. And then clean it *again*. ;)
Make sure you can blow compressed air through all the little holes. I
had the same problem on my abused Aero 80 when I got it. Took me three
tries to get it right, but after that it's always fired right up.
By the way, if either of you are in N. California and ever want to
sell, let me know, I'd love to get a 125 or a second 80.
-- Tom Jupille

Thanks for the extra info Tom

I knew there were some design differences, but not that many.....
There seems to be pretty limited resources on these.
Though, general consensus seems to be the engines are super tough and
long lasting.

Guess I'll have to try my hand at carb cleaning once things settle down
here (in the middle of a kitchen renovation) After this nightmare
cleaning a carb might be relaxing :-)

Say, you wouldn't have a diagram of how the 80 control box ?
I'd like to understand how it works. Wondering why they thought it was
better than a manual choke?

Feel like I'm in California these days, been pretty toasty here, but I'm
on the other side of the continent. :-) Nova Scotia, Canada


Anyways,
Thanks again

[meman]

Ive restored my wifes aero 125 (see list below), if not only because they
are/will be a rarity.
This thing keeps up with my 85 ch150 with the wife on it. Body parts look
great.
Her speedo reads 5-7 mph less than actual paced speed - not sure if that
applies across the board on these models, so be careful if you're worried
about speeding.
The aero 125 is kind of light...the ch150 has more bulk/weight to it...so
going 55 the aero 125 can be unnerving to her just a lil bit.

Now this one has a tip-top auto-bystarter and completly cleaned carb, and it
still can be fussy on COLD start. There is an old trick that works with
these older 2-strokes with starting cold.
- set the RUN switch to off
- start the scoot for 5-7 seconds, maybe lightly feathering the throttle a
bit in quick bursts (it won't start of course...you have it the RUN switch
on OFF).
*if really cold it may take 2 or three of these
- then set the run switch ON (run) and start as usual..
if should fire up for ya pretty quick then. (think of it this as pretty
priming the carb so it will fire up easier).

* your carb and fuel felivery system (tank petcock, fuel line, vac lines)
still should be in good shape and clean
* same for the autobystarter - should be working.

Hit me up if you got questions, I've totally been thru this one.



restored 84 aero 125:

New Piston, rings, and cylinder bore

Complete Final drive replacement (had the parts so why not) and new final
drive gasket

New head gasket and lower cylinder gasket

New brakes

New drive belt

Replaced wth lighter roller weights in variator - with 12.2gr
weights (lighter than new stock aero 125)

New clutch spring

New clutch pads and springs

New Moveable drv face, vclips, drive face (front pulley)

New reed valve

Fully cleaned muffler

New headlight

Cleaned and lightly oiled air filter

Full clean of carborator (inside parts and out)

Cleaned oil filter from reservoir

Replaced old, chaep oil with fresh Honda 2-stroke oil to resovoir

New transmission oil change (Honda 10w-40 4 stroke oil)

Tape quick fix to left rear panel locking plate (mount flap was broken)

Re-adjust brake cable and throttle cables

Fixed windsheild left mounting screw

Added a DEMO rear trunk (removable)

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

[Slickolddude]

Post by meman
Ive restored my wifes aero 125 (see list below), if not only because they
are/will be a rarity.
This thing keeps up with my 85 ch150 with the wife on it. Body parts look
great.
Her speedo reads 5-7 mph less than actual paced speed - not sure if that
applies across the board on these models, so be careful if you're worried
about speeding.
The aero 125 is kind of light...the ch150 has more bulk/weight to it...so
going 55 the aero 125 can be unnerving to her just a lil bit.
Now this one has a tip-top auto-bystarter and completly cleaned carb, and it
still can be fussy on COLD start. There is an old trick that works with
these older 2-strokes with starting cold.
- set the RUN switch to off
- start the scoot for 5-7 seconds, maybe lightly feathering the throttle a
bit in quick bursts (it won't start of course...you have it the RUN switch
on OFF).
*if really cold it may take 2 or three of these
- then set the run switch ON (run) and start as usual..
if should fire up for ya pretty quick then. (think of it this as pretty
priming the carb so it will fire up easier).
* your carb and fuel felivery system (tank petcock, fuel line, vac lines)
still should be in good shape and clean
* same for the autobystarter - should be working.
Hit me up if you got questions, I've totally been thru this one.
New Piston, rings, and cylinder bore
Complete Final drive replacement (had the parts so why not) and new final
drive gasket
New head gasket and lower cylinder gasket
New brakes
New drive belt
Replaced wth lighter roller weights in variator - with 12.2gr
weights (lighter than new stock aero 125)
New clutch spring
New clutch pads and springs
New Moveable drv face, vclips, drive face (front pulley)
New reed valve
Fully cleaned muffler
New headlight
Cleaned and lightly oiled air filter
Full clean of carborator (inside parts and out)
Cleaned oil filter from reservoir
Replaced old, chaep oil with fresh Honda 2-stroke oil to resovoir
New transmission oil change (Honda 10w-40 4 stroke oil)
Tape quick fix to left rear panel locking plate (mount flap was broken)
Re-adjust brake cable and throttle cables
Fixed windsheild left mounting screw
Added a DEMO rear trunk (removable)

Post by Slickolddude
I recently bought a 1984 Honda Aero for $100. It has only 3400 miles
and looks pretty nice. I've already replaced the front tire and
modified the side covers to get them to fit better since the plastic
studs broke off. It runs real nice and rides like new. I do need to
figure why it starts so hard when it's cold. Anyone have and ideas or
fixes for the cold start problems?

Can you still get the new auto bystarter units thru Honda? I also heard
one guy say he modified the auto btstarter unit and added a manual
choke? How about total carb replacement? I have a 1978 Ct-90 with the
old reliable manual choke that starts first kick and runs and idles
perfect. Any idea if that sort of carb could be put on the aero 125?

[meman]

Unfortunately, I don't think you can get new autobystarters anymore.
I would bet you can find used with some hunting though.
I am also interested in hearing about a manual choke addition to this carb.

Taking a guess - please correct me anyone in the know:
the autobystarter needle pushes DOWN as the autobystarter is warmed up (wax
or some type warming up upon voltage).
or...is that the reverse, i need to check that. Anyway, yeah I think it's
very possible to alter it for manual choke with the orig carb.

They DO go bad, but more often than not, it's a scenario such as I described
(start RUN switch off - then again with it ON), or the carb could use a jet
cleaning, or float adjustment, etc.

Does yours fire up at all? Please describe a cold start for you.

Post by Slickolddude
Can you still get the new auto bystarter units thru Honda? I also heard
one guy say he modified the auto btstarter unit and added a manual
choke? How about total carb replacement? I have a 1978 Ct-90 with the
old reliable manual choke that starts first kick and runs and idles
perfect. Any idea if that sort of carb could be put on the aero 125?

[vex]

Post by meman
Unfortunately, I don't think you can get new autobystarters anymore.
I would bet you can find used with some hunting though.
I am also interested in hearing about a manual choke addition to this carb.

My understanding is that the autobystarters are no longer available. And I
need two of them :-/

I'd be interested in a manual choke addition as well. I'm currently resigned
to replacing both carbs with Mikuni VM20 units that have a manual choke.
I've found them on the 'net for ~$70US.

Post by meman
the autobystarter needle pushes DOWN as the autobystarter is warmed
up (wax or some type warming up upon voltage).
or...is that the reverse, i need to check that.

That's my understanding as well. The function of the autobystarter is to
limit airflow when cold, thereby increasing fuel ratio.

Post by meman
They DO go bad, but more often than not, it's a scenario such as I
described (start RUN switch off - then again with it ON), or the carb
could use a jet cleaning, or float adjustment, etc.
Does yours fire up at all? Please describe a cold start for you.

Mine fire and run, when it's above 50 degrees F.

Where did you find lighter variator weights? After I get these two machines
up and running well, I'll be doing them too.

[Steve Burgess]

Post by vex

Post by meman
Unfortunately, I don't think you can get new autobystarters anymore.
I would bet you can find used with some hunting though.
I am also interested in hearing about a manual choke addition to this carb.

My understanding is that the autobystarters are no longer available. And I
need two of them :-/
I'd be interested in a manual choke addition as well. I'm currently resigned
to replacing both carbs with Mikuni VM20 units that have a manual choke.
I've found them on the 'net for ~$70US.

Post by meman
the autobystarter needle pushes DOWN as the autobystarter is warmed
up (wax or some type warming up upon voltage).
or...is that the reverse, i need to check that.

That's my understanding as well. The function of the autobystarter is to
limit airflow when cold, thereby increasing fuel ratio.

Post by meman
They DO go bad, but more often than not, it's a scenario such as I
described (start RUN switch off - then again with it ON), or the carb
could use a jet cleaning, or float adjustment, etc.
Does yours fire up at all? Please describe a cold start for you.

Mine fire and run, when it's above 50 degrees F.
Where did you find lighter variator weights? After I get these two machines
up and running well, I'll be doing them too.

Think of the autobystarter as an anti-choke....
Instead of limiting air it actually adds fuel instead....
(thereby also being called the fuel enrichment circuit)