1984 Honda aero, running issues...

[hondaaero50s]

I have been working on this scooter for a few weeks now. This being only my 2nd time working on a moped.

I now have an 1985 nb50 and an 1984 nb50.

As for a history on the scoot it was worked on previously by an individual that seemed to know less than I, so I am sure that will complicate things.

It came with a new carb (seems a bit different), the old carb (dirty), no fenders and no airbox...

It has however had the cdi upgraded already...

It runs, kinda. as it was when I got it - starts up fast, idles well, but when the throttle is applied it revs to the sky, forcing me to kill the engine (in fear or blowing it as there is no rev limit on the cdi). If i start the bike after this engine kill without turning the a/f screw all the way out it automatically high revs. So basically I would start the bike, throttle up, it would hang and continue to rev, I kill engine and have to back the a/f screw all the way back out. I also noticed that the bottom screw in this carb looks as if it has been over-tightened (the tip is flattened irregularly)

I adjusted the carb, inspected the needle and seat, learned a ton about carbs I never knew, cleaned both the new carb and the old carb, and alot more that didnt work.

If I install the old carb after cleaning it, the bike seems to idle fairly well... sometimes. Cant explain that. But if
I give it any gas it bogs and dies... I should note here that the scoot does not high rev or try to with the old carb.

I feel that i should clean the old carb again and to install an air filter for this thing to get the proper air ratio in the carb.

I have a regular cone type air filter I have been using, will that work or am I required to find the one for this bike?

Any suggestions on where to go from here?

UPDATE
I just took off the carb from my properly running 85, installed in onto the 84 with a bit of coaxing, and it fired right up (with the airbox of course)
I would like to use the original carb as I cannot identify the other one and it acts all crazy.

Am I right to believe all I need is a good cleaning?

[patthesoundguy]

I say yes give the carb a good going over and install a new air filter in the airbox. Dont use the cone filter. All of these Hondas do not like going without the stock airbox unless you upjet the carb to larger jet. Thats why the scooter reved to the moon and bogs out when you put load on it, its running lean as can be.

[hondaaero50s]

Well it seems all I actually needed was to seriously attack the carb. I did so and have since fired it up. I attached the cone filter and adjusted the carb to work with it for now and it runs fairly well!

What jet size would I need to keep using the cone filter? i have been looking for a filter box but cant seem to find one anywhere.

[Pancake Sauce]

A properly sealed, properly filtered, stock airbox is my recommendation for it. Each cone filter will likely provide a different intake and resistance so 1-size-fits-all jetting likely wont work for it. It might cost you $30-50 but my Aero 80 and Spree were super touchy with anything other than the stock filter, sealed, and with a properly oiled filter element inside.

Even simply unclipping a corner of my spree airbox would cause all sorts of chaos to ensue, and the Aero 80 wouldn't stay running after warmup without the airbox. I eventually caved and dropped $40 on a used airbox. It has since been driven about 700 miles and even gone on a few 60 mile trips without any issues. That one $40 change I made turned an unusable Aero 80 into a daily driver. Ebay has them often for $30-60.