81 ATC200 Running RICH no matter what I do!

[NickN]

81 honda atc 200 runs rich no matter what I do. I have brand new carb. New piston and rings, valves relapped, new valve guide seals, timing set with timing light while engine is running f mark lines up with timing mark using timing light. Tried different carbs to no avail even new ebay carb same thing no matter what adjustments i make it still runs rich when i rev it up a little black smoke comes out if i turn the air screw in all the way shuts bike right off like it is suppose to do and every carb i use i cant get it to idle i turn up idle to set air screw its more accurate i dial it in with the air screw makes it idle high and smooth then i back off the slide screw to bring the idle back to normal and it will stall in less then a min turn idle screw in to keep from stalling then revs to much sprayed carb cleaner on intake and around to check for vacuum leaks there are none valves set at .005 i have the filter and air box removed still runs rich any one ever figure this out i am missing some thing please any help would be great thanks

[tri again]

Sounds like you're on the right track.

can you click on:
service manual

Under 'normal' circumstances, I'd imagine
a mouse nest in the airbox or frame intake
but that's obviously not the case.

Those 200 carbs are so simple but I remember
the 'w' clip that holds the main big needle DOWN into
the carb slide flipped over on me once.
so the needle would settle where it felt like.

It's been years so that may also have been a trail 90
but it drove me nutts for a few days, swapping known working
carbs, but it was part of the throttle cable and not the carb itself.

You could also try dropping the needle a clip or 2.
Someone with a 185 or 200 should chime in soon, if
for no other reason, to make fun of my memory issues.

and they'll know the actual jet sizes that need to be in there
to start.

Did you happen to get a non oem exhaust?
less restriction usually makes them run funky
without tons of jetting.

Your new engine is also breathing better but should not be that far off
unless the carbs were changed to compensate for the
'old' engine.

[rg97]

Nick, just a suggestion
Work on your grammar!!!!!!
I was through the 2nd line of your post before I got lost. I almost couldn't make sense of it all. Next time you post, please use periods!!!

[tri again]

wow
my eyes are so bad I missed the punctuation entirely.

I'd sure like to see that thing run the way it should.

If you've never had a trike that ran right, you're in for a treat.

Yeah, PLEASE let me know if those even have that 'w' clip.
or whatever you find wrong.

we ALL need to know

[NickN]

Sorry for the grammar issue. I actually found a prior post which explained my case exactly, so I just copied and pasted. However, no answers in their replies.

I have the service manual which I followed to the letter. One thing I haven't spent much time on is the exhaust. I simply blasted and painted. Therefore, yesterday I tried to remove the spark arrester with no luck. Not sure how to remove without damaging. Very well may be clogged somewhat.

To answer the other question, yes this carb has the needle clip retainer. I did not make any changes to the throttle valve yet. I will take a look today and adjust if needed.

Would the black dry deposits on the plug equate to a fuel issue only? No blue smoke. Just small burst of black. Sometimes barely visible.

One other thought is the fact the engine does not change when I back the pilot screw out. Almost fell out, however I was paying attention. It does correctly respond when I tighten though. Also, I haven't re-installed everything, testing thus far is at idle with a few revs here and there.

[kb0nly]

If you cant get that arrestor out its very possible your exhaust is restricted and causing the issue.

[PAPA250r]

One thing i have found . "new" ebay carbs are
Crap and "new" rebuild kits for them are also crap either moose or no name import kits . I had almost the same issue as you untill i got all oem carb parts for my 200s and tuned it to the manual specs.

The moose rebuild kit and oem needles were visibly different .

[NickN]

Thanks PAPA250r. I will try the rebuild kit.

[kb0nly]

The new carbs are no problem, however the jet sizes that come in them vary along with the needle. What i do is re-use my stock needle and jets after a thorough cleaning. Normally i don't replace a carb unless its last ditch effort due to a worn slide bore or damaged parts, bad threads, etc... But i have used a more than a few of the chinese carbs, first thing i do is pop the bowl off and spray it out to make sure its clean as some of them have come to me with what looks like casting sand in the bottom, then i swap the jets with the stock jets, or buy new oem jets if they are too far gone, and it usually fires up and runs no problem after install. A little tweaking of the mixture screw while reading the plug after a few rides usually dials it in.

I used to be picky and try to keep the stock carbs, enough fighting the damn things i just replace them unless they are in really good shape.