1984 Bystarter

[Jimmy Appel]

Is there more than one bystarter, or more specifically is there a difference in bystarters (electric choke) for various models/years of scooters, or are they all the same? If they are different, what part number should I be looking for a 1984 Honda Spree 50cc scooter?
I cleaned out the carb super spotless, replaced the broken bystarter with an after market one, but it still will not start unless I squirt raw fuel into the carb. If I squirt raw fuel into the carb, it starts up right away and runs until the squirted fuel is consumed. It appears to have a good flow of fuel from the petcock when vacuum is applied to it, but perhaps I need to clean out this unit also (the only thing I haven't tried yet). New airbox filter, and yes the top is secured tightly......... Oh yes, the fuel bowel appears to have a goodly amount of fuel in it, as when I remove the drain screw, alot pours out of it.

[martynkim]

Did you clean the emulsion tube under the jet?

[Jimmy Appel]

Did you clean the emulsion tube under the jet?

I am pretty sure I cleaned out all the various brass pick-up tubes. I soaked the dissembled carb and its parts (minus the various O rings) in carb cleaner for 3 days, and used high pressure air to blow out each and every passage I could find.

[Johnniespeed]

Did you clean out the orifice that feeds fuel to the bystarter ? It is less than .016" but must be open to provide fuel to the bystarter. It is located in the float bowl cover.

[mousewheels]

Did you clean out the orifice that feeds fuel to the bystarter ? It is less than .016" but must be open to provide fuel to the bystarter. It is located in the float bowl cover.

+1 - Johnniespeed and I were editing at the same time.

I cleaned out the carb super spotless, replaced the broken bystarter with an after market one, but it still will not start unless I squirt raw fuel into the carb. If I squirt raw fuel into the carb, it starts up right away and runs until the squirted fuel is consumed....

Our 'wiki is down, which is where the most detailed bystarter info lives.

Two ideas worth ruling out:

1) A clogged passage between the main carb bowl, and the tube directly underneath the Bystarter. It's approx. 0.75" on the scale on the pic below


2) Aftermarket bystarters are hit-miss for good functionality on our scooters. Different vendors may/may not have a part that works like OEM.See this link

[Jimmy Appel]

NO! I saw that, but thought it was a "roll pin" as it didn't look like a passage way, I am sure that is the problem. Thanks......

[Johnniespeed]

That picture that mousewheels provided is great, that orifice shown is almost always clogged. The scooter will be extremely hard ( if not impossible) to start when that tiny hole is clogged.
If it is open, you can shine a penlight through it , or you can spray carb cleaner through it. Either way, it must be open.
Hope you get it sorted out and running good.

[Jimmy Appel]

No amount of poking, applying a vacuum, or high pressure (about 100 pounds air pressure) will clear out this passage, so I put the bowel back into the carb cleaner and maybe will allow it to soak a week in it (hopefully this will loosen the obstruction). If worse comes to worse, maybe I will try to drill it out to .75mm (as a last resort). I tried a .71mm allen wrench with the end sharpened to a flat head screwdriver shape, put this in a drill and still can not pass air through the passage (filled the bowel with fluid and applied 100 lbs air pressure to the large exit passage.... no bubbles)

When you said .75" I assume you more likely meant .75mm (as .75" is awful large)

[mousewheels]

When you said .75" I assume you more likely meant .75mm (as .75" is awful large)

The pic shows 0.75" as a measurement from bottom of bowl, to approx. the orifice location.

If worse comes to worse, maybe I will try to drill it out to .75mm (as a last resort).

The passage is used as a metering jet. 0.75mm will be rich when cold. Around 0.33mm is close. I have roughly sized the orifice to 0.013" using wire gauges in 0.001" increments.

-- Orifice
A 0.010" wire was used in the pic. Try a straightened strand from a bicycle shift cable or the smallest guitar string.

Bystarter_Bowl_wire_passthrough.JPG (53.69 KiB) Viewed 4137 times

[Johnniespeed]

My smallest jet drill is .016" ( .002" smaller than a R.C.H.) , that orifice is smaller than .016"
If the hole was .750" you could stick your little finger into it.
I had one I couldn't get clear, I used glass beading until I wore a hole through the float bowl.
Luckily there are lots of old carbs laying around, just ask your scooter buddies, they probably have a several laying around. Grab another float bowl.