1987 Aero NB50 confirmation of oil pump working?

[papa_eos]

Amazingly, I had this scooter sitting in my garage since 1993 gathering dust(purchased new 1989 now has 1975mi.). I drained the gas and oil, cleaned both filters, took off the carb and cleaned it as this forum suggested. Could put mixed gas in the cylinder and it would run until gas ran out, but would not stay running.

This morning gave it one more try by choking the carb with my fingers which for some reason the Aero started and has been working since. Put the airbox back on with a temp air filter and wide open throttle flat ground goes close to 40mph. I'm running 40-1 in the tank just to be safe. Seems to run great.

I am concerned about the oil pump though, I downloaded the 85 service manual from here and it mentions getting air out of the oil outake line. I used a syringe with oil fed into the outtake line in which it should come out of the intake fitting--nothing goes in. This model has the throttle cable connected(the 85 manual does not show this), maybe it doesn't work like that on this oil pump.

I did remove the 2 screws on the oil pump to check inside, it did seem ok, hopefully this didn't change anything. What can I do to confirm operation? I hope I haven't been to verbose in my first post.

Thanks in advance for any help, this forum has been invaluable in getting it running

[devenex]

Not too verbose at all, nothing wrong with a long informative explanation

Well since you're already running premix you can just disconnect the line that goes from the pump to the intake then plug the nipple on the intake. Now just start the scooter and see if oil comes out the line.

I don't know the exact expected flow rate off the top of my head unfortunately, but I'm sure someone else can chime in w/ it shortly.

[Kenny_McCormic]

With bike at idle you should see it producing a drop every 10 seconds or so.

[papa_eos]

Thanks I'll give that a try. Just got back from some errands and tried to do a cold start(sat for 4 hours) and it wouldn't kick start(my battery is dead). I opened the air box and put my fingers over the carb air intake and it started again and runs great.

The bystarter measured 6 ohms before I put it all back together, I have a feeling that it may not be getting any fuel in that separate bowl. That separate brass fitting on the side of the main bowl going into the bystarter bowl seemed to be clogged. I tried a piece of 26 ga. solid copper wire to see if it would go in.

Does anyone know if that tiny hole goes straight through to that bowl? If that was clogged would that stop the cold starts? I forgot how frustrating and rewarding this whole process can be, I had a Puch Moped back in the early 80's before I got my Driver's License that was always doing something that needed tinkering.

[Wheelman-111]

Greetings:

Welcome, too. That hole does go through, not sure how straight the path.

When you hand-choked it probably sucked an epoxy-like plug the size of an idle circuit through. There may be others after 16 years of evaporation. Sure sounds like a bystarter circuit issue.

Get a can of carb dunk. Next time it looks like rain for a few days, take the carb apart again and soak for 48h. Then go through it with a fine bristle and de-plug everything you see.

6 ohms is fine. You can make sure by measuring bystarter "erection" before and after 12V application for 5 min. 5mm is all you need.

40MPH is good. Mine ran 38 stock, which it didn't stay for long.

[mikehailwood]

Some Sprees, Elites and Expresses have this same walled off enriching chamber in the float bowl. All of the ones I've worked on had a straight hole. Carb cleaner followed by a tiny broach opened this passage. If I filled the small chamber with gas it would not flow into the main float bowl chamber. Seems like if I put the gas in the main float bowl chamber it would flow, though, into the small chamber (assuming the passage was open).

[papa_eos]

I finally got this passage open, to confirm I put some carb cleaner in the small bowl, put my compressed air can straw on that tiny fitting in the main bowl and saw a good stream of bubbles coming up.

Amazingly, I went to my local Honda shop and ordered the gasket kit for the carb, a seat latch and some new mirrors(which actually look identical to the OEM one's), got the parts in 2 days and for less money than online. I hope the new gasket for the bystarter and cleaning that last orifice will give me reliable cold starting.

The oil pump in the Elite_SA 50 manual on this site is the one on my Aero NB 50. The recommendation above to cover the oil intake on the manifold then just let the bike idle or rev with the line coming out of the oil pump unhooked did the trick. It does drip oil out of it at a slow pace which seems to meet the criteria, good thing I've got premix in the tank.

So far so good.

[Jdept]

Would anyone tell me if I were to run my '86 NB50 w/o the pump would it cause damage to the engine? I've read that some of these 2-stroke oil pumps vary the amount of oil with RPM, the more RPM the more oil, is this how our pumps work? Is 32 to 1 a safe mix when not using a pump?

[evilone]

32:1 is good. You will need to upjet. Yes the oil pumps work that way. Why not just replace the pump?

[Jdept]

Well I was just asking because this is what the PO was doing. And the piston and cylinder are more likely to be blown and their maybe more damage; such as to the crankcase. I haven't checked it all out yet. I was looking for some advice whether I should part it out or fix it. It has good tires, a doppler expansion exhaust, blinkers all-around, but the plastics are a little dinged up and there's a bunch of stickers on them. I have been given spare tubes, rollers, and other miscellaneous bolts with the scoot. Just would like to know if I should spend the $200+ to have it rideable & reliable or part it out and probably break even?

This would be my first scoot and 2-stroke ...it looks far easier than my flat-four honda but looking at the value of these scoots and then the cost of the parts ...it seems the parts are of more value than the scoots are ..... just looking at KBB



My post : viewtopic.php?f=1&t=20161&p=174219#p174219

[evilone]

I'd personally spend $200 and fix it.

[Bear45-70]

I'd personally spend $200 and fix it.

+1

[maddog]

do you know there is an oil screen at the oil tank line connection, you also don't know that bacteria breeds in oil which gums up the screen thus reduces the oil flow= check it out

[Horseracebill]

I have a 1986 Honda Aero 50 that won't start I can't figure out if it's the oil or what can I put the aero 50 on a diagnostic machine and maybe it could tell me?

[motormike]

I have a 1986 Honda Aero 50 that won't start I can't figure out if it's the oil or what can I put the aero 50 on a diagnostic machine and maybe it could tell me?

No, Horseracebill, no diagnostic machine is going to tell you what is wrong with your scooter.
There are several steps to follow in order for you to diagnose the problem.
1. Does the ignition system work ? Confirm spark present at the plug gap.
2. Is there fuel being delivered properly by the carburetor and petcock ?
a. confirm petcock flow by pulling vacuum on the line from intake to petcock.
b.confirm fuel in the bowl to proper level. There are simple methods.
3. Does the engine spin freely with compression, and does it create sufficient vacuum to pull fuel through carburetor ?
a. you may need to check with compression gauge if firing doesn't occur.
This^^ is your basic outline for almost every scooter...good luck sir...motor