200x Build Performance Carb Question

[ZachH]

Howdy Guys,
I am building this 1984 ATC 200x currently. Its been my project over the past year. I had her all together and ready to fire and the damn kicker wouldn't catch for a full kick. Then I hung my head, took a couple pics for motivation and rolled her back in the shop. So I ordered a kicker upgrade kit from shortline today to solve that issue. I have plans to purchase a few more things such as a Prm skidplate set, aftermarket grab bar etc. Anyway what I've installed is as follows, 389a web cam, web valve springs, 67mm 12:1 Wiseco Piston, DID cam chain, Barnett Dirt Digger clutch and springs, Dg exhaust, and new valves with a fresh valve job. I will be using this 200x on the track only obviously. So my question is, What intake and carb combo do you all recommend? I've heard XR200 intake and carb. If so what jetting etc.? I look forward to all of your input.
Thanks,
Zach

[Tacky]

Nice ride. I just installed the 214 cam in mine with performance springs, 66mm 12.1 wiesco, with the ebc clutch and heavy duty springs 10%. Running a 93 octane and klotz hitrate race mix for fuel. I also used a DID cam chain in mine. I replaced my kick start ratchets and spring when I split the cases for new oem ones. No problems now.


I am interested in a carb upgrade. I have seen alot of guys running the mikuni vm28 flatside and heard great results. It does require a new inlet, but I have seen a 2 hole to 28mm rubber flange adpater on ebay for $20 that allows the use of a 28mm on the atc jug. Will be watching the thread as well.

Right now with the stock carb I am running a 130 main, and still working on the correct pilot, currently a 45 keihin.

[jsmay]

I ran a xr200 carb, it worked well but the bike I was using it on was pretty stock... just a pipe. I did like the upgrade though and it was all Honda parts. I actually bought the intake/carb and twist throttle off eBay for like $45 and it was a complete bolt on. Mickey Dunlap sells modded stock carbs. That would be my first choice, four stroke tech is his company.

[shortline10]

Huge increase in power if you can find and aftermarket 200x manifold , either a Mikuni 28mm flat slide or a round slide TM28mm . Flat slides tend to give better throttle response but lack in bottom end power were the round slide makes real good bottom end power but a little lacking in the upper RPMs . The xr200 carb is better over stock but definitely not making the power like the mikuni set up .

[ZachH]

Huge increase in power if you can find and aftermarket 200x manifold , either a Mikuni 28mm flat slide or a round slide TM28mm . Flat slides tend to give better throttle response but lack in bottom end power were the round slide makes real good bottom end power but a little lacking in the upper RPMs . The xr200 carb is better over stock but definitely not making the power like the mikuni set up .

Any ideas on where to find a manifold? What are your thoughts on the Four stroke Tech carb mentioned above? I had looked into them but they are pretty close in price as a genuine mikuni you reccomended. Any experience with it?

[ZachH]

Nice ride. I just installed the 214 cam in mine with performance springs, 66mm 12.1 wiesco, with the ebc clutch and heavy duty springs 10%. Running a 93 octane and klotz hitrate race mix for fuel. I also used a DID cam chain in mine. I replaced my kick start ratchets and spring when I split the cases for new oem ones. No problems now.


I am interested in a carb upgrade. I have seen alot of guys running the mikuni vm28 flatside and heard great results. It does require a new inlet, but I have seen a 2 hole to 28mm rubber flange adpater on ebay for $20 that allows the use of a 28mm on the atc jug. Will be watching the thread as well.

Right now with the stock carb I am running a 130 main, and still working on the correct pilot, currently a 45 keihin.

Could you provide the link to the adapter?

[oldskool83]

Might better to give HRE the spec of said manifold so he could just make somthing for you guys. Unless a bunch of you want to pull money together so I can provide green sand castings of new parts...I work in a foundry and have unlimited access said things.

[Gabriel]

I’d be in for a couple at least if you could put together a group buy and make some.
Current options.....wait....what options?

Find an old one on Ebay or nothing.

[Tacky]

Could you provide the link to the adapter? I have been eyeballing this one along with a 28mm mikuni.

https://www.ebay.com/itm/Mikuni-Flange-Adapter-for-VM28-30-Carburetors/392103369075?redirect=mobile

[ZachH]

I have been eyeballing this one along with a 28mm mikuni.

https://www.ebay.com/itm/Mikuni-Flange-Adapter-for-VM28-30-Carburetors/392103369075?redirect=mobile

Thanks! Might be the way to go. Ill let you know if I try it out.

[shortline10]

If I remember right Mickey did a pretty good job testing that carburetor he sells , my experience is only with mikuni .
The spigot aftermarket manifolds pop up on eBay every blue moon .



Any ideas on where to find a manifold? What are your thoughts on the Four stroke Tech carb mentioned above? I had looked into them but they are pretty close in price as a genuine mikuni you reccomended. Any experience with it?

[Dirtcrasher]

Did you get any port work done?? I'd definitely make sure to find someone to port it for you guys to compliment the other mods you've done...

[ZachH]

Did you get any port work done?? I'd definitely make sure to find someone to port it for you guys to compliment the other mods you've done...

That's in the plan for sure. I just want to find the right place to have it done. Recommendations?

[kiser]

I built an '81 185 for my wife a few years ago and couldn't keep the motor stock while it was torn apart lol. I ended up making an aluminum spigot intake for it. I got the aluminum, cut it to the length and angle that I wanted and had a buddy tig it. It was ported to match the port work in the head and worked great! Pretty cheap also!

[Tri-Z 250]

I've seen some guys run Crf 150r carbs on modified motors. How much mod work and intake to jetting was done, not sure. I've just seen it work on a few TT 200x's at the NatyBula.

[Dirtcrasher]

I bet you will NEVER EVER EVER again put a motor back together without perfect kicker parts will you?? :lol:

Glad your all set!

[Tacky]

Thanks! Might be the way to go. Ill let you know if I try it out.

Yes definately let me know if you try it, I have been trying to decide if I was gonna go with the 28 mikuni, and I have a clamp on filter I can use its a uni with precharger. However I have not given up on the factory one just yet....but that may change.

[Tacky]

I bet you will NEVER EVER EVER again put a motor back together without perfect kicker parts will you?? :lol:

Glad your all set!

I would not, thats why I dropped $100 for an oem bnib set for mine. The others were missing a bit on the 10.25 to 1, so I knew 12.1 to 1 would be way worse. Didn't want to take a chance.

Think the only one I have had that was worse was my 2003 raptor 660. It had electric but it had 6 or 8 socket head bolts that secured the starter gear to the one way bearing. It had a bad habit of shearing them off, and dropping the heads in the bottom of the motor. Replaced with the strongest I could get from fastenal, lasted way longer than stock, but over time the compression would snap them too. I do not miss that but still miss the bike, it was quick with the ct racing mods I had on it.

[ZachH]

Hey shortline, sorry to open an old thread but I have gotten my x up and running and am ready for a carb, will the flat slide mikuni fit in the frame without mods?

[shortline10]

Yes it fits but you need the short intake manifold , if you use the longer version then the frame needs dented in a little and possibly one of the over flow / vent tubes on the carburetor trimmed .

[ZachH]

Yes it fits but you need the short intake manifold , if you use the longer version then the frame needs dented in a little and possibly one of the over flow / vent tubes on the carburetor trimmed .

Any idea where to look?
Your kicker gears fixed me right up by the way! Thanks again for that!

[shortline10]

Manifolds are hard to come by , possibly place a wanted ad here and keep an eye on eBay or make one .