Can the ByStarter be Saved?

[RZRob]

I've got two 50s (1983 Aero 50 & 1985 Spree 50). Both are VERY CLEAN and run FANTASTIC except.... Both require about 3-5 minutes of intravenous feeding of starting fluid (or else they run out of gas) until something goes [figuratively speaking] click in the carbs and then they idle right, purr like kittens and run like showroom.

The Bystarters are getting warm, and the carbs are clean. It seems like the bikes are clearly not getting gas until something magically happens after a few minutes of running on life support. I don't think I can buy replacement Bystarters, but what's really going on?

Any advice? I'm desperate.

RZ Rob

[mousewheels]

The bystarter valve controls an extra air path and a fuel path. The needle controls the fuel, the brass collar the air. In the carb bowl is a small brass orifice which meters fuel into the 'well' from the main bowl. w

A likely cause of your problem is the orifice is clogged. Possibly, the bystarter needle is somehow stuck to where no extra fuel can be drawn.

[RZRob]

A likely cause of your problem is the orifice is clogged. Possibly, the bystarter needle is somehow stuck to where no extra fuel can be drawn.

Unless there's something I'm not getting, the passage ways that I'm seeing are HUGE and clear sailing (like maybe 1/16" opening).

I agree with you that the Bystarters on both bikes appear to be "Sticking" but I can't quite seem to figure out how to make them go through the motions as they should - and when they should.

Should I consider "soaking" them in some cleaner, taking them apart or just moving the plunger a bunch of times by hand?

I sincerely appreciate the advice from those more experienced than I.

RZ Rob

[mousewheels]

I agree with you that the Bystarters on both bikes appear to be "Sticking" but I can't quite seem to figure out how to make them go through the motions as they should - and when they should.

Should I consider "soaking" them in some cleaner, taking them apart or just moving the plunger a bunch of times by hand?

I think the bystarter is moving fine- because your engine runs better after approx the time it takes for the bystarter to warm up and extend. You can pull it off cold and run a bench test if you want to observe its action. Also - there's a check of the air valve portion of the bystarter functionality details in the Service manual.

Here's a pic of the orifice in the carb bowl that clogs, & in fact - this one is clogged pretty badly.

[RZRob]

Here's a pic of the orifice in the carb bowl that clogs, & in fact - this one is clogged pretty badly.

I think you just solved the mystery. I was concentrating on the passageways in the body of the carb. I barely gave the bowl a passing glance besides cleaning out the 1/4" of tar in the base.

I'll let you know how it goes.

I guess I never understood the whole flow circuit on the carb for fuel, air, and enrichment (choke).

Thanks for the help - and the picture. That was gold.

RZ Rob

[Wheelman-111]

Greetings:

I don't think anyone ever expresses enough appreciation for all the Mouse does around here. He's helped me a lot too. I don't know how he does his trick with the saving of Honda-san's Service Manual diagrams, coloring 'em in, and posting them here. Genius.

[RZRob]

Well, I started on one of the bikes ('83 Aero 50) and found the jet on the bowl and it was definitely clogged. Eventually I got it where I was blowing carb spray in the big hole in the bowl, and it was spraying out the small orifice in the bowl.

The encouraging thing was the bike started on its own and even idled for a moment, but eventually just acted like it didn't have enough gas.

I'm really stumped. I guess I'll pull the carb back off.

I wonder if I should buy a new plug. It was running fine before (and probably still) once it's warmed up.

RZ Rob

[Wheelman-111]

Greetings:

The $3 you spend on a new plug often has surprisingly curative effects. This is particularly true if that old plug endured the combustion of years-old "gasoline", even for a short time. I lost count of the number of times I was fearing the worst was wrong with my engines, only to find that a new spark plug(s) solved everything.

That said, the fuel starvation issue you mentioned suggests that a look and test of the tank fuel strainer and vacuum-operated petcock is prescribed. They gum up and stick just like carbs. I have resurrected a couple of petcocks by soaking in NAPA carb dip, then mineral spirits. Some say the rubber diaphragm can be decomposed by these solvents, but it worked for me.

[RZRob]

The fuel starvation issue you mentioned suggests that a look and test of the tank fuel strainer and vacuum-operated petcock is prescribed.

Well on the '85 it was obvious these items needed addressing as the petcock was stuck. I removed the tank and cleaned it with CLR (and muratic acid) and a serious flushing. The petcock was stuck and then I just sucked really hard on the end and eventually got it to where it moved and worked fine. The '83 (the one I worked on last night) I bypassed this step when I saw the petcock working.

Both bikes run GREAT after the "first finicky five" I guess tonight I'll come home with new plugs, throw one in the '83 and go for a 10 minute ride. The gas may be a questionable mix of old, new and Sea Foam. Then I'll go over to the '85 put a new plug in it and pull the bowl and clean that same orifice. Then, I'll take that one for a good flogging. It's got a clean fuel tank etc.

BTW, this orifice in the bowl, if it were truly clean, should I be able to get a strand of wire through it? I know this is a no no sort of, but the same strand that I used on the emulsion tube holes doesn't feed the distance on the bowl hole. So basically it just got Brake Cleaner and compressed air.

Thanks again folks for your insight and wisdom. I'm definitely walking towards the light.

RZ Rob

[RZRob]

This just in:
OK, I went out this morning and checked to see if the '83 would start on its own volition. It started right up and I was able to work the throttle and keep her going indefinitely as long as I didn't let the revs fall to the flat zone. It was feeling like it'd die down low, I tried and it did. I let it sit for a few minutes and walked back and she started again and ran as long as I didn't let the revs fall to the flat zone. Once that happened she died and wouldn't immediately start. I imagine it will restart though if I go back in 10 minutes and keep her running.

I know these bikes should start and idle even when cold. Also, I live in So Cal. It's been cold, but not that cold.

RZ Rob

[mousewheels]

BTW, this orifice in the bowl, if it were truly clean, should I be able to get a strand of wire through it? I know this is a no no sort of, but the same strand that I used on the emulsion tube holes doesn't feed the distance on the bowl hole. So basically it just got Brake Cleaner and compressed air.

Seems like the wire ought to pass through, and they might on many models. But the first clogged orifice I had bottomed out. Put a ~0.010 piano wire in a Dremel, bored through, and it made new hole.

Here's a pic taken for the 'wiki' last night showing a clear orifice. In the future I will try to get a closer handle on the bore size. I recall 0.020 wire is too large.


---

...how he does his trick with the saving of Honda-san's Service Manual diagrams, coloring 'em in,

Honestly - the coloring is easy - it's just MS Paint , but thanks

[Wheelman-111]

Greetings:

Mousewheels Modestly protests his praise:

Honestly - the coloring is easy - it's just MS Paint , but thanks

Y'see, to me MS means Multiple Sclerosis. I should spend some time learning about these here comfusers...

[RZRob]

Mousewheels, you are truly incredible. You are an asset to this forum. I'm amazed by your photographic talents. I can see that I still don't have that orifice opened up enough. I was being so delicate that the hole's too small and not enough fuel is getting into that passage quick enough.

Do you do Macro Photography as a hobby or career?

I'll keep you posted.

RZ Rob

[RZRob]

Update:
OK, I went in on the '83 Aero first. I readdressed that port on the bowl, and while I think it was clean yesterday, I cleaned it better today and put in a new plug. Now I believe (to your earlier comments) that crud from the tank has found its way back to the pilot circuit (off idle flat spot).

So I went on to the '85. Bowl orifice wasn't completely clogged, but gave it some love. This port comes in at an angle, and you can't see the other end, so it's hard to know when you've got everything, but I was pretty confident. I closed her up and put a plug in too. It runs really good. I won't sign off though until I can just walk up and press & go.

Thanks again for the help. That orifice in the bowl, is the best kept secret.

RZ Rob

[mousewheels]

Hey - good work. When the bystarter circuit is back to factory condition, these scooters are pretty amazing at starting and running smooth.

The photography is a hobby, but like many tools sure is fun.
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Bystarter orifice sizing -- Pic below is a strand of bicycle brake cable (measures 0.010). Didn't get to the hobby shop for some music wire, but remembered from a member a strand from a brake or derailleur cable works. Great tip It looks that the 0.020 music wire that I recall didn't fit should have been close to working, will track down some 0.018 and 0.015. Also, for this carb bowl, the wire sailed right through into the bystarter fuel well, no bottoming out.