round slide vs flat slide carbs

[big red hemi]

im looking at upgrading the stock carb on my 200x first gen. already have a full bassani system.

is there any significant performance gains with a flat slide carb. if so at what rpm range.

[oscarmayer]

get a xr200 carb. it's 2mm larger thanthe stocker 200x. and bolt sright on.

[big red hemi]

i was just wondering why flat slides have become so popular. would the performance they provide be worth the extra effort over 26mm direct bolt on

[shortline10]

Night and day difference between the 2 power wise on a 200x in my experances . I have installed many flatslide mikuni 28mm carbs on the 200x model and it gives you more of a 2 stroke type power band were the round slide give you more even power threw the whole power band . If your gonna race get the flatslide if your trail riding get the round slide . I have to say the flatslides are harder to start the motors in the cold months .

[big red hemi]

thanks stortline 10

that is exactly the kind of info i needed to make up my mind.

oscermayer was right. round slide it is

[mullet_boy]

When they explained the difference in my class at bike school they said basically what shortline said, round is for low end torque, flat is more for high rpm power.

[big red hemi]

thanks mullet

whats your bottom end like with that 30 mm mikuni

[cr480r]

i have a hard time seeing how a round slide could do anything better than an equivalently sized flat slide.. I would run the round slide on a 200, but i cant see how it would add low end

[Erics350x]

From what ive read. You get smoother flow from a flat slide and when tuned right you should get better response, but most of all better topend from the smoother flow and mix of air/fuel. My stroked scrambler 400 had a flat slide and i realy liked the way it performed.

[RapidRick]

The difference is the turbulence of the air/fuel mixture.

[3 or die]

I prefer the round slide on my two strokes. The flat side seem more on and off, not anything in the middle. I hear round slide horor stories but my experiance is if you have a good one to start with, and throw a kit in it it will run for years. Take into concideration if you let any of them sit with this new gas your gonna have trouble if you dont use additive. I also see shade tree mechanics without enough experiance trying all kinds of jetting and pipe combinations This causes many problems and then they blame the carb. My rule is if you dont know how, build it stock, by the book, and ride the crap out of it without any problems. Thats what I do.

[pcs]

how about those reproduction carbs that are listed all over flea bay, i see brand new ones going for around $30, are they any good or are they cheap replacements?
http://cgi.ebay.com/ebaymotors/Carbu...#ht_3940wt_939
also, will a 200x with bolt ons respond well to a larger carb or will it need some motor work to to take advantage?

[trikes4life]

how about those reproduction carbs that are listed all over flea bay, i see brand new ones going for around $30, are they any good or are they cheap replacements?
http://cgi.ebay.com/ebaymotors/Carbu...#ht_3940wt_939
also, will a 200x with bolt ons respond well to a larger carb or will it need some motor work to to take advantage?

Yeah i have bought one in the past. Made my crappy running beater run like it came out of the crate in 84. I bought one to try after i seen this post. http://www.3wheelerworld.com/content...ihin-200x-carb

[RapidRick]

My experience much more than 2-3 mm will take the motor work and should already have the basic intake and exhaust mods already done.

[cr480r]

I prefer the round slide on my two strokes. The flat side seem more on and off, not anything in the middle.

what type of flatslide was it? sounds like a the needle circuit was off... i've never had that problem with keihin pj's and pwk's on 2 strokes.

The difference is the turbulence of the air/fuel mixture.

I can believe that. Thanks for the reply rick.