83 Big Red black smoke

[mrpacman]

Hi, I have a new to me 83 Big Red.
My problem is it is flooding. Black smoke out the muffler especially when I rev it. Previous owner said he cleaned the carb. I disassembled the carb and found.
1. lots of rusty residue and particles.
2. pilot jet was clogged
3. the needle was dropped into the slide on top of the retaining spring. it fell out when I was removing the throttle cable.
I cleaned carb thoroughly, checked floats for leaks, installed needle correctly. Set the air screw about 1.5 turns out from seated.
It runs decent now. But, has this flooding problem. Does anyone have any ideas what is causing this?
Thanks, David

[CodyRosa]

Is the carb leaking out of the overflow? If so I would suggest a rebuild kit by Moose. The black smoke is from running to rich I believe because mine did the same thing.

1. Check your gas tank is it rusty? How rusty? Do you have an inline fuel filter??
2. Those pilot jets are very annoying to clean. If you ever have a real stuck one rip a wire from a wire brush out and use that to stick in there and clean it.. works like a charm!
3. Wait so the guy put that spring that holds the needle down first.. then put the needle on top of that? lol..

Could you maybe have an air leak? What color is your plug.. I'm guessing black? Turn the screw in a little more? Although 1.5 turns doesn't seem like a lot for the air/fuel mixture screw.

[mrpacman]

Thanks for the repy.
I cleaned the pilot with wire brush bristle. Have not checked plug. Air leak sounds like a good possibility. The intake between head and carb has a visible crack.
The carb is not overflowing. Tank doesn't appear to be very rusty. I have not installed an inline filter yet.
This carb looks to be oem and same age of the machine. It will probably be best to just replace the entire carb. Looks like it has been apart several times judging from the screws holding the float bowl etc.
Thanks for the help.

[CodyRosa]

Honestly.. stick with the OEM carb and just get a moose rebuild kit on ebay, they go for around 18 bucks. I bought a Chinese one and had more problems.. not saying there bad there just harder to tune then the OEM. If the screws are starting to strip you could probably buy new screws at a local hardware store? Just match them up and there ya go! Well the tank must have some form of rust on it if that carb has rust in it. I would suggest an inline fuel filter (5 bucks) so rust and whatnot doesn't get in there and clog everything. Does your machine have a high idle at all? Air leaks normally make high idles.

When you say theres a visible crack do you mean the crack where the intake meets the head or is it like a hole where you can put a piece of paper in there? Try checking your plug if its black trying turning the air/fuel mixture screw in maybe a half turn? ride for a few minutes and check it.

[dougspcs]

I know some people don't care for them but I've had pretty good luck with Chinese replacements..

The carb on my 200m was seized from sitting so many years, I took it apart and cleaned it and couldn't get it dialled in. A second pull and clean up and it was not running right..

Cut my losses and bought an EBay carb and it ran perfect..

I guess you just need to figure out when to cut your losses!

[barnett468]

Hi, I have a new to me 83 Big Red.
My problem is it is flooding. Black smoke out the muffler especially when I rev it. Previous owner said he cleaned the carb. I disassembled the carb and found.
1. lots of rusty residue and particles.
2. pilot jet was clogged
3. the needle was dropped into the slide on top of the retaining spring. it fell out when I was removing the throttle cable.
I cleaned carb thoroughly, checked floats for leaks, installed needle correctly. Set the air screw about 1.5 turns out from seated.
It runs decent now. But, has this flooding problem. Does anyone have any ideas what is causing this?
Thanks, David

Hello David


Xlnt description and in line order, very good job it makes it easier.

Needle and seat may have more rust debris in it or needle could be leaking because it is old. Get a small CLEAR fuel filter.

An air leak will cause it to run LEAN. However if it has one it could have been re jetted to compensate for the lean condition.

Does it have fresh gas? Old gas will burn black and bike will run poorly?

Check float level

What are y our jet the jet sizes?

What mods does your bike have?

Install NEW plug after rwpair/rejet and check color after 1 hour riding, what color is it? White/lite tan is good, dark tan is slightly rich, DRY black is too rich, any dampness at all with any color is oil.

I see Dougspcs couldn’t get his OEM to work and Cody had a bad experience with the Chinese one. Both of these things happen however the Chinese ones actually work but you may or may not need to rejet it. OEM carb kit $18.00, Chinese carb $32.00 I think. See Ebay and Amazon.com believe it or not.