Just out of the shop '83 200X running pig rich. Any ideas before I go exploring?

[TheRadBaron]

I bought a well-used '83 ATC200X last fall and I've been refreshing it over the last few months. It started and idled when I got it but I never rode it since the axle bearings were blown out. I just got it all done and took it out for its first spin. It's running extremely rich, so much so that it barely runs. I'm a pretty experienced tuner of vintage Japanese stuff but I'm new to ATCs. I can tell it's rich by how it runs and the plug is really sooty and black. The reason that I'm asking here before I start tearing into the carb again is that sometimes models have a unique problem that they're known for and it might be an easy fix as long as you know what to look for. And you guys are the experts.
When I got the trike I pulled the carb off for cleaning and it had a 108 main jet and a 38 pilot jet. They were both pretty mangled so I replaced them with new genuine Honda jets in the sizes that are specified for the '83. That's a 110 main and a 40 pilot. I also cleaned the carb really well and set the float height by measuring from the float to the carb body surface, as per the manual. The carb looked to be in good shape and I'm pretty confident that I cleaned it well. So it's now jetted just a bit richer than it was when I got it but I wouldn't think that it would be enough to make it run so rich. Plus, they're brand new jets in the sizes that the trike came with.
Anyone have ideas? I figure I'll have to take the carb back off and look around but I though it was worth a shot to ask here first. Thanks.

[YTZ drew]

Maybe this is a silly question, but are you sure its a 200X carb? If its off of a 185/200 automatic, or even an XR100 (all visually identical, it would have a smaller bore than the 200X. Standard jets in a smaller bore carb would equal very rich running.

[TheRadBaron]

Not a bad suggestion. I seem to remember checking the stamped numbers and them being correct but maybe I'm mixed up. I always have a lot of projects going on. I'll check the numbers next time I look at it and verify. I'll try lowering the needle, too. If that helps I'll at least know that I'm moving in the right direction.

[yaegerb]

1983 will be a pd62a and 1984-85 will be a pd62b. Regardless they both use 40 pilots and If it's so Rich it's barely running, adjusting the needle will do nothing for you as that's your main circuit. You need to get your pilot circuit correct. If the carb is a pd62a, lightly seat your pilot screw and then back it out 1-3/4 turns and 2-1/4 for the pd62b. Also if you find its a pd62b your main jet needs to move down to a 108.

[El Camexican]

Is the choke working properly? Can you start it cold without the choke? When it is running and warm will choking it make it stall?

[TheRadBaron]

The carb is indeed the PD62A that it should be. The choke seems to work properly. I haven't tried to start it from cold without the choke but it will certainly stall the motor if I choke it when it's warmed up.
As far as the needle goes, I think the richness problem is more on the main circuit than the idle. I have the needle set at 1 3/4 turns out and the idle quality isn't too bad. It also runs okay when I'm just puttering around at low throttle openings. It doesn't get bad until I open up the throttle a ways. This suggests to me that the problem is more in the main circuit. I just don't know why it's so rich with the 110 main. I have the needle clip in the #3 position that the manual specs, too. I'll probably put the 108 that I took out back in and see what happens. I supposed it's always possible that I got a faulty jet that is flowing too much fuel. Between that and fooling around with the needle hopefully I can make some progress. If not, I guess the carb will be coming back off. Not that that's a big deal.

[oscarmayer]

sounds like you couild look to going to a 108 or even a 105 main.
a dumb questuion, have you checked plug gap? what about the quality of spark? a bad coil, or stator could cause a weak spark this not properly burning all fuel.

1 last thing I wanted to know, have you checked the timing? there is a small amount of timing on the cdi assembly. if it's too far retarded it can cause this issue as well as the spark fires and ends before all the fuel is dumped leaving some unburn fuel in the chamber. there are 2 screws that hold the cdi pickup assembly. there is a cut out notch. there is a line on the housing assembly that aligns to the notch area. it should be center but slightly forward. (forward is counter clock wise). if it is more towards the back of the notch then change that as well.

[yaegerb]

The carb is indeed the PD62A that it should be. The choke seems to work properly. I haven't tried to start it from cold without the choke but it will certainly stall the motor if I choke it when it's warmed up.
As far as the needle goes, I think the richness problem is more on the main circuit than the idle. I have the needle set at 1 3/4 turns out and the idle quality isn't too bad. It also runs okay when I'm just puttering around at low throttle openings. It doesn't get bad until I open up the throttle a ways. This suggests to me that the problem is more in the main circuit. I just don't know why it's so rich with the 110 main. I have the needle clip in the #3 position that the manual specs, too. I'll probably put the 108 that I took out back in and see what happens. I supposed it's always possible that I got a faulty jet that is flowing too much fuel. Between that and fooling around with the needle hopefully I can make some progress. If not, I guess the carb will be coming back off. Not that that's a big deal.

3rd groove on needle and 110 main is the setting and jet you should be using. If its still running rich I would say the float needs to be looked at again to ensure proper height. I would also look at the float valve assembly. Another culprit could be the air jet is clogged in the body itself.
Have you rebuilt the carb yet? The needle jet is a hidden culprit on a lot of carbs I have rebuilt. If you haven't rebuilt it yet I would say get a $20.00 shindy rebuild kit and replace all components.

[YTZ drew]

The needle jet is a hidden culprit on a lot of carbs I have rebuilt. If you haven't rebuilt it yet I would say get a $20.00 shindy rebuild kit and replace all components.

This is a very good point. The needle jet itself is pressed in above the emulsion tube, and does wear out over time from the needle bouncing around inside it. The emulsion tube (below the needle jet, main jet screws into it) has a bunch of tiny cross-drilled holes that can plug up as well. I use a single strand of copper wire to clean them, and make sure I can see light straight thru the cross drilled holes. If those are clogged or the needle jet is worn, that will cause rich running as well.

[TheRadBaron]

Yeah, the rebuild kit is a solid idea. So is verifying the timing. I did clean out the emulsion tube really well when I had the carb apart the first time but I didn't look too closely at the needle jet itself. I'm much more familiar with Mikuni carbs and the needle jet is built into the emulsion tube on Mikunis.
I ordered up a Shindy kit and I'll probably get a chance to take the carb back off today and check on the timing. I prefer to use factory carburetor parts but a lot of them are NLA for this carb. The Shindy kits look to be decent quality, anyway. While I have the carb off I'll clean it again just to be sure and I'll verify the float height and make sure everything else looks proper.
I seem to remember that when I was setting the float height I had to adjust it quite a bit from where it was when I got it. Perhaps I set the fuel level too high. I'm thinking that it wasn't as obvious as I'm used to what part of the float was used to get the 14mm height that the manual specified. Can anyone shed some light on this? A picture maybe? Thanks again.

[oscarmayer]

the center of the float should be at the end of the carb shen it is turned upside down. and should appear level. it is also ok to have a slight "upward" angle to the float but just a very slight. it is NOT ok to have it at a downward angle in any way.

[TheRadBaron]

Come to think of it, my memory of the float in the carb doesn't really match up with the pictures that I'm seeing of the correct float. I might have the wrong float in the carb. Hmmm. I'll pull it apart today and see what it looks like.

[TheRadBaron]

Well, I figured it out. I took the carb off and pulled the float bowl. What did I find laying in the bottom of the bowl? Nothing other than the main jet itself. I guess someone only tightened it finger tight while putting the carb back together. Man, I could have saved myself all this trouble if I had just pulled the plug on the bottom of the float bowl and checked the main. But what could be wrong with the main? I'm an experienced mechanic and I put the carb together so I know it's good, right? D'oh!
Oh well, I'm not in a big hurry to take it for a ride since it's zero degrees or so out. I'll wait for the rebuild kit to show up and I'll rebuild the carb the right way.
The float does look a bit different than the pictures I'm seeing online, though. The pictures show a white-colored plastic float that looks to be hollow. Mine is that black, solid, hard foam material that most modern floats are made out of. Anyone else have a float like this in their 200X?

[oscarmayer]

haha yea that would call all those issues and more. yours was rebuilt looks like at some point which is why you show new floats. i always try to reuse the factory plastic float as i feel they are better quality, but sometimes they are damaged and i am forced to use a new float.

glad the issue was a simple one.

[NeverLift]

I have 3 200x carbs apart now 83-85 and they are all the same white plastic float.