ebay carb for nb50

[devenex]

Bogging is an indication of the tiny jetway not being clean. And visa versa, if the tiny jetway is plugged, it will definitely bog.

If its bogging when given throttle, but not when idling, then the idle jet is clear (the smallest and hardest part to clean). That was what I meant.

So the throttle bogging occurred w/ and w.o airbox? Then I would verify that the main jet is clear.

[tw39515]

i unscrewed the jet cleaned it and could see light, also took out brass tube behind it and cleaned it.can see light through all holes. could bad reeds cause fuel splatter out back of carb.

[devenex]

I believe bad reeds can cause that. Can't hurt to check them. If you are careful in removal you can reuse the paper gaskets and save money.

[Lunytune]

i unscrewed the jet cleaned it and could see light, also took out brass tube behind it and cleaned it.can see light through all holes. could bad reeds cause fuel splatter out back of carb.

Wrong hole. There is another passageway which runs parallel to the main jet passage. It is very tiny and doglegged. You wouldn't be able to see through it. Click on this link and you will see the area that is critical.
http://www.hondaspree.net/phpBB3/viewto ... =3&t=10834

Hey, I just noticed, that's YOUR post. So now you can answer your own question. Is the passage in question clear? In that post you said NO. Is it clear now?

[tw39515]

that was an example bought a spree and a aero. the spree wouldnt idle. ended up buying new used carb and topend. got the spree running perfect. now my problem is with the aero it idles just fine so my best guess is the passage is clear or it wouldnt idle. correct me if im wrong. i noticed that fuel is splashing out of carb where air filter would go when i throttle it. before i could get the aero running i had low compression 60 psi. but after repeated atempts to start it finally got it to idle havent rechecked compression to see if rings un stuck themself. but now it bogs after one full throttle attempt. ps it kicks and starts first time.

[Lunytune]

so my best guess is the passage is clear or it wouldnt idle. correct me if im wrong.

Not necessarily. The symptoms are classic. I'm not exactly sure of the dynamics, but I know what a Hondasan taught me on this, and since then, I've fixed my share of carbs with same problem, quite successfully. When that passage is plugged, engine will start and idle beautifully, but bog when you give it throttle.

But you've got a multitude of problems if you have low compression. Some would say an engine can run on 60psi, but run so poorly, you wouldn't be able to diagnose any other problems. Now that you've got it running some, and should have freed up any stuck rings, run the compression again. If it's still low, consider that in the diagnosis.

[tw39515]

so what the sure fire way to clean that passage and make sure its clean. ive soaked it an used a wir from topside. if its clogged its gotta be in the offset(dogleg). thanks in advance.

[tw39515]

rechecked compression hot only 70 psi.
also took carb apart again found a small plastic syringe filled with seafoam fluid passed through idle jet and main jet so both are clear.
will check reeds tommorrow, only other guess is the low compression.

[tw39515]

any one know stock jet size for 87 nb50

[Lunytune]

rechecked compression hot only 70 psi.
also took carb apart again found a small plastic syringe filled with seafoam fluid passed through idle jet and main jet so both are clear.
will check reeds tommorrow, only other guess is the low compression.

Even the tiny hole? Okay, now that's sure, you can move on to other matters. I just hate to waste time looking for the problem without insuring that one first.

What jet is in it now and what does the plug look like?

On the compression test, do it dry. Then do a wet test (squirting oil in the spark plug hole). It will determine if the low compression is rings or something else.

Fuel misting out back of carb

. Could be indication of weak reed valve, which would also effect compression. Where's Wheelman? He's the expert on reed valve testing.

[tw39515]

will do oil test tonight, and take a look at reeds it was late i thought it said 80 but writing very small wanted to check for stock size, i will double check.

[Wheelman-111]

Greetings:

The majority of 1987 NB50s were delivered with #82s. Some markets (mountains) used a smaller one, methinks. Check MrCycles.com. You can drill down to 1987, then NB50 and then carburetor for the sizes Honda-san specified. Part number 99101-187-0820 is the 82.

[Lunytune]

will do oil test tonight, and take a look at reeds it was late i thought it said 80 but writing very small wanted to check for stock size, i will double check.

Yeah, I understand that small writing. I have to have bright light and magnifying glass to read the jets.

[tw39515]

cool thanks guys i verified 82 size jet, put oil down cylinder and it bought compression up. but it sounds like the engine is runnig out of fuel. it runs balls out for 5-10 secs then bogs. but idles fine.