200s Performance

[bigredder]

Okay, it's been a while since I've been on here because I've been without an ATC for a long while. But, picked up a 1984 200s for cheap and got her going great again. So, now my question is what can I do to make it a little faster? Besides sprockets and whatnot. I'm wondering about maybe a different cam? What are your guys's thoughts?

[knipfeldustin]

i put a 10.25:1 compression piston, a xr200 cam and aftermarket exhaust on mine to give it more power. I added a 27mm carb as well. Seemed to bump it up quite a bit. There are higher compression pistons available than that as well but i didn't want to get into running race gas. Porting is always an option as well and a couple places offer better cams but if you want cheap what i did is about your best bet. Mine is in an autox so i also opted for carbon fiber clutch plates and heavy duty springs to help with the larger tires i run (25").

[ArizonaATC]

i put a 10.25:1 compression piston, a xr200 cam and aftermarket exhaust on mine to give it more power. I added a 27mm carb as well. Seemed to bump it up quite a bit. There are higher compression pistons available than that as well but i didn't want to get into running race gas. Porting is always an option as well and a couple places offer better cams but if you want cheap what i did is about your best bet. Mine is in an autox so i also opted for carbon fiber clutch plates and heavy duty springs to help with the larger tires i run (25").

This guy pretty much said it all, the 200s is a great machine, have fun!

[schlepp29]

I'm building an auto x from the ground up right now. Good info!

[Scootertrash]

i put a 10.25:1 compression piston, a xr200 cam and aftermarket exhaust on mine to give it more power. I added a 27mm carb as well. Seemed to bump it up quite a bit. There are higher compression pistons available than that as well but i didn't want to get into running race gas. Porting is always an option as well and a couple places offer better cams but if you want cheap what i did is about your best bet. Mine is in an autox so i also opted for carbon fiber clutch plates and heavy duty springs to help with the larger tires i run (25").

I have the same build in my 84 200S, I have a SuperTrapp exhaust on mine and an XR200 carb and manifold.

Snce knip mentioned porting, I didn't have mine professionally ported, but I cleaned up the casting marks in the ports and evened things out a bit. I polished the exhaust port but left, I think, about an 60 or 80 grit finish in the intake port. I also matched the intake and exhaust manifolds with the ports and lined them up when I installed them. Kind of anal for a 200cc motor but hey, every little bit helps.

knip: Got a link to the 27mm carb?

[knipfeldustin]

knip: Got a link to the 27mm carb?


I dont have a link but i just bought a chineese one off ebay out of california, It was less than $20 just make sure to pick one that has the actual measurements in the pics, ive been burned in the past on the ones that dont show the measurements and ended up being smaller than they advertised. Alot of people say these carbs are junk but ive ran these chineese carbs for years now on my autox with no issues. i was running a 22mm one prior to last engine rebuild and it was on there two years without an issue. I just wanted more power so i upgraded.

search 27mm 200x atc carb on ebay and youll find plenty of options.

I didnt have to do any adjustment to it besides the idle as far as that goes.

[bigredder]

i put a 10.25:1 compression piston, a xr200 cam and aftermarket exhaust on mine to give it more power. I added a 27mm carb as well. Seemed to bump it up quite a bit. There are higher compression pistons available than that as well but i didn't want to get into running race gas. Porting is always an option as well and a couple places offer better cams but if you want cheap what i did is about your best bet. Mine is in an autox so i also opted for carbon fiber clutch plates and heavy duty springs to help with the larger tires i run (25").

How do you like the power? Is it a significant difference from stock or just a little noticeable? My machine doesn't smoke a drop and has great compression and I don't want to mess with it unless it is a somewhat significant gain.

[knipfeldustin]

There is definatly a gain you can feel power wise. I am much happier with mine vs what it was stock. If your not wanting to do any engine work, changing your sprocket sizes will allow you to adjust your low end power vs top end speed.

smaller in the front sprocket=lower gearing
Larger in front sprocket=higher gearing

Larger in the rear sprocket=lower gearing
Smaller in the rear= higher gearing

i think somehwere around 4 teeth in the rear equals 1 tooth on the front in either direction.

im not sure what options are available on the 200s model as far as sprockets you'll just have to shop around.

bigger sprockets mean you may need a longer chain so keep that in mind as well when ordering.

[Ghostv2]

How do you like the power? Is it a significant difference from stock or just a little noticeable? My machine doesn't smoke a drop and has great compression and I don't want to mess with it unless it is a somewhat significant gain.

If you don't want to open the motor up there are still options that will wake it up significantly. Bolt on parts as mentioned above. Cam, easy installation. Just gotta make sure you set your timing again. Carb, manifold, exhaust. Start there, you'll be more than happy. If you need any help just download a free PDF manual and any remaining questions can be answered by us.

I have an 85 and the 200s is the bike I grew up on and is still my favorite ride to this day. Mines still all stock though, don't wanna hot rod it since my dad got it brand new. I have a 250r and a hopped up pauter 110 if I wanna race.