Need help with atc 200s

[brady123]

I recently became the proud owner of a 1986 ATC 200S engine in a 1986 ATC250X frame. It's a nice solid machine. I got it for almost nothing because it wouldn't start for the previous owner. The machine has great compression and has spark. I cleaned the carburetor thoroughly, including all the jets, and sprayed everything down with carburetor cleaner. I put it all together and pulled it over and over with no results. I took out the spark plug and it was hopelessly fouled. Like jet black. I cleaned the plug and put it back in and pulled it over and.... it started!!! For about 3 seconds and sounded great. It didn't smoke or anything either. Then, it shut off as fast as it started. I pulled the plug again, and it was black. I cleaned it, put it back, and started it for another 3 seconds or so, then it fouled the plug again. After fouling 6 or 7 plugs, i pulled the carburetor off again and checked the fuel mixture screw. I tried to turn in the screw to count the turns, and found it was turned all the way in solid. I turned it out a turn and a half, and reinstalled the carburetor. Now it won't even burp or anything. I clean the plug, put it back, pull it over, take it out, and it's jet black again. I've tried a D8EA and a D7EA, plugs. Sorry for the long post but PLEASE help if anybody has any ideas. P.S. I don't know if those are the right plugs, they just came with the wheeler. Thanks in advance!

[dtuned]

Make sure to take the Jets out to the carb both main and idol jet all little HOLES must be clear and make sure to take take the carb float and plunger out to check for obstruction and check the gas inlet for obstruction if all of that is clean u should be getting fuel enough to run the engine actually and far as plugs do u clean then or replace them me being me I never clean plugs unless I might HAVE to like stuck in the middle of no were but my point is don't clean plugs replace them u get alot better results

[brady123]

I tried a new plug and it didn't help. The carburetor is completely clean.

[mendoAu]

My book calls for a DR8ES-L plug but double check. Just cause a plug looks good after you clean it doesn't mean it is going to give you good spark. You said you cleaned every up. Did you notice any gunky oil/crud build up at the head-cylinder gasket area? Bad head gasket? Have you checked to make sure your valves are opening and closing? When you checked your spark was it dull yellow or bright white/blue. Have you removed your coil and cleaned the screws going to the frame (one is a coil ground). And the last thing I'd recommend is to read some of the threads about your CDI unit (my guess).

[jerkin]

Not sure how much experience you have working on these things but there are several passages in those carburetors and they all need to be clean (not just the jets) for it to operate correctly. Sounds like a carb issue to me so first thing I'd do is completely disassemble the carb again and completely clean it and set the float. Use the red straw on the carb cleaner and clean any hole you see, when you spray it in one hole you should see it come out somewhere else.

Your air screw being turned all the way in tells me two things, either it was getting too much air or not enough gas so you could be chasing an air leak too. I'd put a new plug in it and pull it 8 or 10 times then pull the plug and see if it's wet. If it is wet then you know you're getting at least some fuel to the cylinder.

[brady123]

I put in a DR8ESL plug in and noticed that my problem is spark not fuel. The plug is wet with gas and won't even start with a little bit of starter fluid in the cylinder. If i pull out the plug and rest it on metal and pull it over it sparks 1 out of 10 times usually, and it's a weak spark. Kill switch is not on, new plug, and cleaned the ground wire and mounting location. I can jump start it barely and if it does start it barely runs and the throttle does nothing. So I think its a timing issue but I have no idea how to check

[ironchop]

I'm confused.

You say it will run if jumped? ("I can jump start it barely") Which I'm guessing means its electric start? I'm asking because a 200S is a pull start motor...no starter. Its also chain drive and not shaft like the 250SX so someone would have to adapt to shaft for that to work unless they were changing the whole rear end. Are you sure its a 200S motor in a ATC 250SX chassis? Or is it a 200X chassis?



Post some pics and maybe we can get an idea of what you have goin on.

The reason this all might be relevant is where it concerns how the conversion from a battery reg/rectifier motor to a batteryless 200S motor was accomplished. Did they use the 250SX CDI box and coil or the 200S unit. The coil is probably interchangeable but the CDI may not be......if its a 200X chassis and they used 200X electrics with a 200S motor then I know for sure that would work fine together.

You definitely need a free manual so you can learn how to quickly test your ignition coil, source coil, and CDI unit.

Go here:
oscarmayer.net




Sent from my Z998 using Tapatalk

[yaegerb]

Not understanding this either. Don't know how that engine swap into a 250sx frame would work. Are you sure it's not a 200x frame? Much easier/well known swap. Regardless I have found that cleaning a 30 year old carb doesn't cut it. You need to disassemble and rebuild with a kit. I recommend shindy. It also sounds like your spark is weak/erratic. time to ohm some electrical components. My money is on the coil.

[mendoAu]

Brady, So I'm guessing that you have used the search button here (http://www.3wheelerworld.com/showthr...ent-MythBusted) and brought yourself up to date on CDI units. If you need another source click on this link:
http://4strokes.com/technical/cdi-testing/

It may be the coil but like I said before I'm thinking that since you have good compression and a fouled plug your irratic spark is sucking in enough fuel but you only get spark for a short time with a weak spark and that allows the plug to foul when you give it throttle. That sounds like a faulty, semi working CDI unit. Now true, it may be the wrong CDI unit but if it works at all it should at least idle unless it's like time to replace it. Everything you need to know is right here posted by some really smart guys...just have to read...read...read.
Bottom line is that for like less than 40 bucks you can go to e-bay and get a new coil, plug wire and CDI unit and know that those things will be good for many years in the future.

[brady123]

I'm sorry guys, yes it's a 200s in a 200x frame. My apologies. I was typing faster than i thought apparently. I will try a new coil and CDI. Is it possible that the bad CDI would only let it spark once every few pulls? And i have also heard that the CDI you have to buy for these is pretty specific and that ebay doesn't always have the correct unit. Sorry for all the questions.

[RUNMEDOWN]

Soak the carb in Pine sol yes Pine Sol google it, it works great and does not kill gaskets

[ironchop]

I'm sorry guys, yes it's a 200s in a 200x frame. My apologies. I was typing faster than i thought apparently. I will try a new coil and CDI. Is it possible that the bad CDI would only let it spark once every few pulls? And i have also heard that the CDI you have to buy for these is pretty specific and that ebay doesn't always have the correct unit. Sorry for all the questions.

not a problem at all and NEVER be sorry for asking a lot of questions.

could be any number of things producing intermittent spark. It will be hard to track down until you test your coil, cdi, and source coil. Hard to diagnose over the internet.

There are many many tutorials and such on putting the 200S motor in a 200X frame on here. It`s actually a pretty popular conversion so chances are someone can help you. I put an Estart Lifan 200cc motor in one of my own 200X chassis. All the electrics were included with the motor to set up for estart so I used them instead of the 200X stuff.

[brady123]

Well everybody, thank you for the replies so far. There is obviously an incredible amount of knowledge on this website. I decided to take the spark plug out of my brothers atc 200s engine and try it in mine. And to my astonishment, it burped a couple times after about 50 pulls on the rope. I took off the cap that says CDI and was surprised to see that it had a decent coating of rust on the inside. I gently cleaned it all up so it looks nice and clean now. I noticed that the piece that rotates when the pull starter is pulled has a small shallow groove in it right down the middle almost like it is rubbing on the bottom of the pulse "thing/box/black thing". I took a piece of binder paper and slid it between the rotating piece and the small black box and rubbed it back and forth until there was no more rust. I put the cap back on and tried it again. Surprisingly, it now burps and coughs and does more than it ever has on every pull. When I was changing the spark plug, I noticed that the 10mm bolt directly opposite the cdi cap was only in by about one thread??? Is this related to the valves and cam shaft? If so is the problem now that I have a tight/loose valve?

[mendoAu]

brady, that cover you took off just says CDI on it 'cause it's that kind of electrical system. You have now located the "pulse generator" and NOT the cdi unit I was referring to. Now one last time....take the time to read the links that have been provided to you. (twice) I'll try to get you on the right path but if you read the provided links and download the FREE service manual you will gain the knowledge to get that puppy up and running. This is a CDI unit: ( http://www.ebay.com/sch/i.html?_nkw=..._dmd=1&_ipg=50 ) You should be able to locate it under the gas tank..just follow the wires entering the coil.

[brady123]

I cleaned all elictrical components, checked the cdi box, adjusted the valves, brand new plug, fresh gas, rewound recoil, and nothing. It sparks on every pull but won't even start with starting fluid in the spark plug hole. One on every 50 pulls or so it will start for 1-2 seconds then die. It's no longer fouling plugs, but just won't run. I think that the timing is correct but I haven't checked yet because I don't know how. I read almost the entire manual and I cant think of anything. I'm considering scrapping it but the price of steel is way down right now. I'll try to upload a picture of it but I don't know if it will work