Mikuni 30mm

[LivinProof]

Hi guys. After changing the exhaust and the air filter on my Superbyke RSP i was running lean and the engine was overheating. As I got no help in my topic a bit underneath this one I've done loooooads of research and found out that the best thing i can do is simply put on a bigger carburetor. So, I got myself a Mikuni 30mm, fitted It with a 105 main jet and... Can't get It to work on the bike. :( First thing - The idle starts on 2k rpm then moves slowly up to 3k rpm. Second thing - Without full choke won't start. The first time I have fitted It after a little while the fuel started coming out of the air filter. Twisting throttle just kills the engine. Tried with many different needle positions and the best one seems to be lowest notch, but there's loads of white smoke coming out of the exhaust. Please help guys. I have no idea what to do with that. :/

[LivinProof]

Ok, to make it more clear, I've managed to sort most of the things out. Now the bike is running but in the top end It dies. Also gets hot pretty quick which would indicate a lean mixture, however the main jet is 105, needle is on the lowest notch and the mixture screw is already 2,5 turn out. Any ideas what might be the problem? Sorry for double posting but I could really use some help here and I'm desperate :D

That's the plug reading:
http://i58.tinypic.com/34no7cn.jpg

[lagerlout07]

Hi

Sorry my reply is abit late i have a k157fmi engine and fitted a mikuni 30mm to it. What i did with the setup was fit my old needle, pilot and main jet rod intonthe 30mm and stuck a 115 jet on the bottom. This allowed me to setup the carb easier, the 30mm is for 150cc+ bike and i could never get it idle, or throttle off. It would just flood petrol and cut out all the time. I also havve to start the bike every time with choke on, once its started you can just knock it off if its not cold that is :)

[LivinProof]

I feel like I almost got it right. It idles properly (needs a minute on idle when cold) but needle on the middle notch still seem to flood it. I'll try in the morning to get the needle up one more notch and then see. It drives really well now, only gets flooded over 8k rpm with the throttle wide open. I'll share the settings once I get them right :)

Thanks for your reply, I know more people has the mikunis yet somehow nobody wants to share their experiences :p

[LivinProof]

So, I have literally tried everything and what seems to be the best setup is: air/fuel 1,5 turn, needle on a middle notch, main jet 105. needle any higher - won't rev at all, needle any lower - gets flooded if too much throttle used. With this setup works pretty well I would say, It's got more torque, but you need to be careful with throttle as If opened quickly the engine will get flooded. I've also ordered NGK Iridium spark plug and I'll see If that helps. So far I wouldn't recommend this mod. Leave the stock carb, only rejet It to like 105 or 110. ;)