ATC200X Round slide Mikuni 28mm or 30 upgrade from back then

[jmikkelsen]

Way back in 1983 a great parts guy Named Steve at Gridley Growers Honda set me up with starting specs for putting an ordinary two stroke style Mikuni on my 200. He and his buddies raced three wheelers, so he knew exactly what I needed. I've forgotten nearly everything now, except that it was a round slide carb with round outlet - not the standard two bolt style. It was either a 28mm or 30mm model. I bought a different slide to change the cutaway jetting, and changed just about every other jet too. Though I can't find Steve anymore, I sure hope somebody here can help me duplicate the popular set up from back then. Sure, there are easy to find oem style carbs on ebay, but I'd really like to duplicate what I have back then instead. Sentimental reasons and all that.

Shortline10 was recommend as a knowledgable good guy. Shortline10, I'd sure love to hear from you!!

Next, I have to get an ATC200X parts chassis out of the garage as I've removed everything I need. Off to list it on the for sale area now.

Thanks folks!
Jon

[shortline10]

A 28mm round slide mikuni is fine with a mild motor and a 30mm with a stroker set up . What your looking for is an aftermarket intake manifold specific for the 83-85 200x with spigot mount . Search the site their are lots of pics or look at my albums their should be a few pics their . I believe run a muck had one for sale a few days back also .

[jmikkelsen]

Thanks for replying about the manifold and for the tip that leads me to the 28mm being the size carb for my state of tune.

What I really meant to ask for is baseline jetting specs for the carb, including the slide cutaway.

Thanks,
Jon

[jmikkelsen]

Then again, maybe the 30mm would be better. I'll be using this on a motocross course, not spending a whole of time at low rpms. If you have a starting point for jetting for either carb, I'll be way happy to hear it.
Thanks!!!
Jon

[shortline10]

30mm is to big for a 200x unless your going to run a stroker crank . 28mm is best and easier to jet . I would start off with a 200 main jet a 38 idle and I believe the slide is a 1.5 . I have a new old stock 28mm mikuni in stock that I might consider selling .

[jmikkelsen]

You would sure be doing me a big favor by confirming that slide cutaway. A buddy in town here has a 28mm carb, and I am already getting him my spare pair of Elsinore forks. That's pretty much free-ish, though I did just rebuild the forks.... A 1.5 slide is the big question for me, as I know it is suppossed to be different in some way from two stroke dirt bike setup, and my buddy's already has a 1.5 slide in it. Could I be so lucky? Naw, history says probably not.
Thank you,
Jon

[seadoo650]

I've got a complete setup with a 30mm (bored to a 31mm) for sale. Like Mike says though, it is setup for a stroker motor. P.m. me for details.