Building a 85' Honda ATC 200M, have a few motor questions

[Velislide]

Used to ride my old 1980 atc 200 everyday when I was a kid. Well, almost 30 now, and picked up a cheap spare bike for friends to ride, and occasionally I'll ride it too. Came with two motors, one runs great, but the output shaft for sprocket, must have worn the bearing out years ago, because its been wobbling in the case and oval'd that out extremely bad. Luckily, I got a 2nd motor with it. Another 200 motor with electric start, must be off a big red as it has the high and low range. Been rebuilding the top end of that motor, as it looks like it has sat for a long, long time. Rusty valves, cylinder walls, corroded intake and exhaust ports, etc.

Tore down the top end, crank spins nice and free, oil looked good, no water or anything I could see, pulled the mag cover, flywheel and all, bearings look great with no rust at all, or any play, and shifts free. So I had the cylinder bored over to 65.5 MM, new Wiseco top end kit with a 10.25 comp forged piston. Cam was in great shape, lobes looked like new, but the cam bushing was really stuck on there, could turn it with pliers, but wouldn't come off. I ended up ordering a 1987 Honda XR200R camshaft for it, that was virtually new. New timing chain, and guides also. Just waiting on the new cam bushing to arrive.

Now from my understanding, this cam should be bolt n' go? No messing around with valve springs? Or would upgrading valve springs be a good idea? After I get everything running, and motor seems to be solid, I plan on upgrading the exhaust to that DG ebay exhaust, and going with a 26-27mm carb. After that, should be a solid bike.

Anyone have any other recommendations for bringing this thing back to health? Also, what kind of lighting can this stator handle?


As far as the bike goes, original plastics are in nice shape with no cracks, seat is in great shape with one rip, pretty much everything is there on the bike. New tires also. Managed to get it all, with both motors, for 200$.

[Mackus84]

Alot of people dislike the DG exhaust for these bikes. I have the full exhaust on my 200X (basically same motor) and i really like it. Seems to give a good amount of grunt. But it is LOUD LOUD LOUD. Just a warning. I also run a 26mm keihin carb and intake off a 1990 Xr200R. Remove your airbox lid for some more power, and make sure you jet it accordingly. I run a 118 main, and 40 pilot and i think i need to go up to a 120 main. Im not familiar with the 200M, but i know for a fact that the carb and intake will bolt up to the motor, just not sure of clearances w the frame and stuff as my X is obviously different from your M in that aspect.. So good filter, good exhaust, xr cam, bigger carb and wiseco piston should set you up nice. You should be pretty happy w the gains over a stock bike. My X easily lifts the front wheel in 3rd gear and in 4th w a little effort on my part and im over 250Lbs and tall and i have the exact same parts on mine other then the Xr cam, which i plan on doing. And as far as i know, stock valves and springs should be ok w that cam.

[Velislide]

I think I'd probably like the DG exhaust. From the videos, I think it sounds nice. I doubt it is much louder then my quad, which I plan on getting a full exhaust for also eventually. Even the stock exhaust on that 1000r is pretty dang loud. But thanks for the info, and jetting info, will come in handy for sure and give me a good baseline for when I do the exhaust and carb. I'm guessing I'll have to do something with the clutch, probably freshen it up, with the added power? Any brands of friction discs to watch out for? I know eBay has some cheap junk on there, that I should probably avoid.

And as far as carbs, flat or round? Or won't it matter much on such a small motor.

Annnnd, one last question. Is there an easy way to test if the oil pump is working? I read about popping a bolt out on the head, but wouldn't it be bad to run the motor, if the pump is bad? Or would oil start shooting immediately.

[86125m]

i hve an old school dg on my 200m basically the same as your bike just no high and low. I personally like my dg pipe and it defiantly is quieter than the rusted excuse for a muffler it had.

[BarnBoy]

Good to see someone fixing up these utility trikes! You did great on the price with that bike, especially with 2 motors and new tires. I can't think of too much else to check, for sure wheel bearings, sprockets and chain, and brakes and you should be good to go.

As far as the lighting and stator goes, it will easily run the stock headlight and tailight with more juice to spare. I have heard of guys putting 12v outlets on theirs, and it does fine with the extra draw. Even winches can be run off of this bike, so so extra lights should be no problem. What kind of lighting are you thinking of adding?

[Velislide]

Probably going to do some type of LED light bar setup, instead of the factory headlight. Possibly two light bars, actually.

[Velislide]

Finally got everything, so assembling the motor now. Will I need to rejet for the cam? Or can I run the stock jetting for now? Also with the high and low range, I cleaned it all up, everything felt in good shape, but when the motor is in neutral and I try to spin the sprocket by hand, it feels really notchy and is hard to turn? That normal? Guess I will find out once I run it.

Blah. Couldn't figure out how to remove the electric starter on my old motor, took the bracket off, thing was rock solid still. Deadblow on the gear side, and still wouldn't move. Yanked the two long Philips and split the starter accidently, fell apart, shims fell out from inside. Put it back together, and now it doesn't turn freely. If I pull it apart slightly, its fine. Guessing I lost a shim, as I've looked everywhere and don't see one. Super annoyed, as these starters are crazy overpriced, and mine looks like it's brand new, and worked great. Anyone know where I can buy those shims? Or any advice?

[Velislide]

Okay, so motors running good. Haven't had a chance to ride it, as the rear wheel bearings are totally shot and siezed. But it runs.

So I ordered the DG exhaust off eBay, a late model 200x carb, K&N filter w/ prefilter, new throttle cable and other minor things. Anyone have a good recommendation on a baseline tune? Would the factory jets from the 200x, work well with my xr200r cam, and the new exhaust + intake? Or what should I bump the jets up to? And is there any jet kits available, with a bunch of different size jets? I used to have a nice kit for my banshee, was hoping to find something for the 200x carb also.

Thinking 120 main, and 40 pilot?

[DohcBikes]

Late model?

When using the 965 pn carb, you'll be around 112 to 118 for a main. Stock pilot (40) is fine if your carb is clean with proper float height.

[Velislide]

Carb in the listing fits a 85/86 200x, and is off a running bike. Just so I didn't have to wait, I ordered a few jets, a 118 and 120 mains, and a new 40 pilot. Should get me started at least. Better to start rich and work my way down I'd guess? Will be sonic cleaning the carb when I get it. One thing I didn't even think to check, is if I'd need a new intake manifold. Assume it fits the stock 200M one? I don't see why it wouldn't.

[barnett468]

.
ok, well unfortunately most of this info is too late because i wasn't around to post it when you started your thread due to things that were totally out of my control.

yes, you should run stiffer springs . first of all, your stock ones are 30 years old and have lost some tension . secondly, even if it does seem to run well, the valves could be lofting some at high pm and stiffer springs will reduce the potential for them to do so and may give you a few more peak rpm.

you will get more power with a little porting in the proper areas and by back cutting the intake valve if the one you use has a lip on the back side, however, any porting should be done by a knowledgeable professional because it is easy to loose power if material is removed in the wrong area . bigger is not always better.

the intake boot and intake port should be the same size as the bore of the carb as measured at the outlet, not the venturi.

even though your clutch may not slip, if you flog the bejesus out of it, it will last longer if you run stiffer springs or preload the stock ones around 2 mm with flat washers if you can find ones that will fit . AN style washers often work . you can also check the length of the stock springs to see if they are within spec . the spec is listed in the service manual on oscarmayer.com or by kbonly . if yours are shorter than spec and you use them, i would add washers until the overall length is around 2 mm longer than spec.

not all light bars are the same . if you want lots of light you need to spend big bucks on a high quality light bar, however, if you aren't racing the baja 1000, a cheapo chinese light bar or two will work fine and will provide a lot more light than a stock one will . i actually have some info on chinese light bars and i know a couple that do provide more light than most others and the cost is only a few dollars more . i posted that info along with a lot of other tech info on a thread by oscarmayer titled something like "baja bike" . i will try to find it later today for you.


PREVIOUS KAWASAKI INTERNATIONAL R & D PROJECT ENGINEER AND ATV DEPARTMENT SUPERVISOR

[Velislide]

Thanks for the info. I mainly wanted a little more power then stock, doesn't need to squeeze every last drop of power. It really is just going to be a little beater bike, that I screw around on occasionally, and also let friends ride. I doubt it will see WOT very often, just wanted a little more grunt. I'd assume, with just the bolt on's I did, and the cam, it should be a little better then stock? Even stock would have been fine, any 200 I rode in the past, was totally pissed out, and pretty beat up, but still had enough power to have fun.

[Velislide]

Have a quick question. Before I go ripping into the wheeler, 200x carb came today, but it's missing the slide. Will the 200M carb slide fit it? Or should I find one off ebay? I figured it would come with it, since it was "pulled from a running machne", though the picture didn't show much.

Edit: NM different part numbers, guessing 200x slide is a bit bigger. Well, hopefully seller will send me one. Would have been nice to know it wasn't there.