Bing to Mikuni swap on 1977 WR250

Greetings, A friend of mine is giving me a new Mikuni TM38 flat slide carb and I wish to use it on a 1977 WR250 that has the stock Bing. I know there are some staunch Bing fans here but I'm throwing in the towel on mine. Does anybody know what jets I need for the Mikuni? Has anyone on here done this swap or know where to steer me. Any advice on base line settings at sea level, jetting, intake manifold and carb to airbox boot would be greatly appreciated. I know just enough to get myself into trouble.

My goal is to make this a more dependable easy to start bike for my wife. She loves the bike but we have been chasing carburetor and ignition gremlins for our 3 years of ownership and now we have decided to just go new carb & new mzb ignition. I can't afford a Lectron and a MZB so I opted for the free Mikuni and a new MZB.

I have a mikuni on my 78 cr250. The bike runs and starts great. It's my favorite bike to ride. Look in vintage parts and tech on this site. Lots of info on where to get what you need.You should be able to find the carb to air box with no problem, along with the intake mount. You can also find them on ebay. I'll have to look and see what jetting I have mine at.I don't have the flat slide but it should be close.

ditch the bing!! much easier to find parts and work with the mikuni! altho the vm roundslide would be easier to jet and fit i think. the flatslide tm still takes most of the same jets as the vm and is a big upgrade

The TM38 is not going to work very well, it was Mikuni's first try at a flat slide carb and it was a poor performer in general in addition to being much harder to fit to your bike than the round slide VM.

Well maybe this free Mikuni isn't such a good deal after all. Do I need a new intake manifold for the round slide VM or does it fit within the bing parameters?

I thought I had the jetting written down but I don't. I'll have to pull the bowl and see what is in there.

I can't believe it but the main on my 250 is a 440 and a 35 pilot. I'm at 1100 ft above sea level.

My 76 250WR with a 38mm Mikuni has a 370 main.

Seems a little on the fat side to me mine has a 360 Main 78 250CR I may fatten that up a little but it does run awsome.

My 78 cr250 ( it's a 76 motor) runs very crisp and very smooth. Best running husky I have.

I am new to all this, can someone eplainto me how to set the jetting? i mean looking at my Bing carb. there are no numbers to just turn a nut or screw to. How do you get these numbers and even more, how do you set jetting??? thanks dont mean to open up a can of worms here.