You need to post your specs.
Stock carb specs are 53 pop off (1.5 needle with 115 gr spring). 130 main 70 pilot.
Limited boat will run okay with a stock popoff of 53 with the stock airbox, although you may need a lower popoff and smaller pilot jet with aftermarket carbs. I'm strictly discussing stock airbox.
My limited has about everything but the airbox is stock. The JM kit included a 135 main and 75 pilot. I get clean idle with 1.25 on low end screws with pretty good snap. I'm not done tuning because my 135 main is too lean for me and my new jets just showed up today.
In any case, read the mikuni manual and work it out. Low speed screws can make your ski rich/lean so you need to fiddle with them 1st. If you big is immediately off idle your issue is the pilot. If your big is after 1/4 then its likely the main.
Sounds like your issue is either your low speed screw or pilot. It can be hard to tell of the ski is rich or lean. Start by making the low speed screws richer and see what happens. If it gets worse, make them leaner and see if it goes away. Frequently check your plugs and heat and be careful.
If you haven't read the mikuni manual, read it. If you have read it, read it again. JM has jets in stock and ships fast.
