What should I do with my mikuni carb

[gabeshong]

My first toy! 1980 Yamaha Tri moto 125 with stock Mikuni vm20ss carb
Came with no filter. Put lawn mower(cone type) in the box just for now. The end of the air box was broke so I just cut it of. Its not a bad setup but my wheeler just bogs down after 1/3 throttle so I shoved a thick rag in the end of the air box and now it runs good. I'm wondering what other people would do on a tight budget. Just change the main jet? Would that work if I wanted to run a K&N air filter? And If I wanted to go with a different carb what could I use and what do you recommended? Thank you

[Mr_RPM]

run a UNI or K&N clamp on filter, www.denniskirk.com

[dcreel]

With the airbox opened up or replaced with a cone type filter you will have to rejet the carb for the additional airflow. As far as the carb goes, you may want to take it apart. Clean it up, go up a size on the main jet. I wouldn't get a new carb if the one you have is running good and close with the jetting. Unless you put a pipe on it too, then a new larger carb and K&N filter will get you more power.

[Vealmonkey]

Your best bet if you are stick with a 125 cylinder and piston is to get an 84 or 85 yt125 carb and a nicer airbox used off of ebay or a board member and do that. If you are going with a 175 set up, then you need to get the whole top end and carb and airbo and fuel pump off the 175 and use those. You will need the 175 ehaust pipe too. If you are using the stock 125 pipe, then there really is no use for anything other than a stock late model carb.