86 areo nb50 wont rev out help

[wwolvert]

Im working on a stock 1986 nb50 and it is running rich and wont rev out i checked all the obvious thing I can think of i have cleaned and replaced all rubber in the carb blew threw all fuel and air passages cleaned jets and it has a 82 main jet.

it has a new air filter but on the air box lid where it seals up with the air filter the plastic is wavy im guessing it was installed wrong at some point

I can pinch the fuel line with some pliers to restrict fuel flow and it will rev out like it should

any info will help thanks

[motormike]

I can pinch the fuel line with some pliers to restrict fuel flow and it will rev out like it should
any info will help thanks

The statement above seems to be pointing in the direction of the float bowl.
Fuel level too high ?
Float may be bad, cracked, not floating as it should.
Float needle bad?...try a new one.

[wwolvert]

It has a new float valve but I haven't checked to see if the float is floating yet I'll do that today

[wwolvert]

ok so I checked out the float it is in good shape no cracks and it floated in a cup of fuel for a half hour.I shined a flash light up to it and could not see fuel inside of float

the scooter idles perfect but is very sluggish when trying to rev out it has 115 psi compression and the exhaust is clear no clogs or any thing. it seams to smoke more than normal tho.

all the rubber parts and float valve have been replaced and all the passages and jets spray good straight steams when spraying carb clean through the air passages with the jets installed

do the nb50s have any timing advance when revved up when I look at the fire mark on the fly wheel with a timing light the fire mark is lined up with the indicator at idle, but when i rise the rpms the mark retards away from the indicator goes clockwise away from the indicator correct me if I'm wrong i think this is what is going on .

please help this thing is kicking my butt

[ck_ni]

I had a similar problem with my 86 nb50, in the end it was the air / fuel mix screw... It was wound to far out, screwing it in which increased the idle speed... then backed out the throttle screw to a nice slow idle... Runs 100% after that.

[kuromi]

Any timing advance/ retard would be handled by the CDI.
Are you running a stock CDI?

[patthesoundguy]

Maybe the seat in the carb needs to be polished with a cotton swab with some toothpaste and a drill. And maybe the exhaust needs some attention. You may have a blocked up exhaust port or pipe or both. Look for things that block airflow. Clogged intake or exhaust.

[wwolvert]

yes I have a stock cdi box the scooter is completely stock I removed the exhaust and could not see any blockage in the pipe or the exhaust port I also ran some solvent through the exhaust. The air box is all clear as well.

does any one know if a 1988 sa50 elite cdi box will work on a nb50 ?

[patthesoundguy]

Most of the cdi boxes are interchangeable as long as they have the same plug as far as I know. I have swapped my spree and my aero 80 cdi around and my dio motor is running on a spree wiring harness. Stock oem is best some of the cheap after market stuff won't work well. That being said I have a cheap cdi as a spare that works fine. I keep it in the tool bag just in case

[wwolvert]

So i figured it out.
It seems that some one had reamed or drilled the pilot brass tube out in the carb with something, making it about four times the normal size.
The hole is about the size of the main jet hole, so I will need to get a new carb.

[patthesoundguy]

So i figured it out.
It seams that some one had reamed or drilled the pilot brass tube out in the carb with some thing making it about four times the normal size.
The hole is about the size of the main jet hole, so I will need to get a new carb.

find a soldering gun or good hot soldering iron and solder over the end of the tube with 60/40 electronic solder and try drilling the hole the stock diameter.
it may work.

[wwolvert]

That's a good idea I'm might have to try that I already got a different carb but it would be cool if I could get that to work.

[Ruckenstein]

Im working on a stock 1986 nb50 and it is running rich and wont rev out i checked all the obvious thing I can think of i have cleaned and replaced all rubber in the carb blew threw all fuel and air passages cleaned jets and it has a 82 main jet.

it has a new air filter but on the air box lid where it seals up with the air filter the plastic is wavy im guessing it was installed wrong at some point

I can pinch the fuel line with some pliers to restrict fuel flow and it will rev out like it should

any info will help thanks

If I had seen this post, I totally would have mentioned a jet check. Just went through the exact same issue with an Aero 80. Wanted to throw it off a cliff.