ok so I pulled out the 172 main installed a 180 left the 48 pilot in and set needle clip on the 3rd poss. from the flat spot on the needle.
now with the fuel/air screw backed out 2 turns it will idle fine with the intake off but when you put the intake on it will bairly start and won't idle I pulled the plug and its soaked with fuel
I don't realy know squat about carbs this is just were I set it up after installing all my parts below in sig. any gidance would be great on what all the jets and needle do. I do know the fuel/air screw will richen it if its backed out but thats about it is it poss. to big of main.

 

id try going with a smaller jet and turn the mixer screw in 1 turn and then see how it runs then

 

i swapped out the 180 main for the 175 backed fuel screw out 2 turns now the plu is lean and stll won't fire

 

turn the air fuel mixter screw out 2 turns then it will run richer then try to start it and see how it will run what octane are you running in it

 

Your missing something.

IMHO a jet change that small won't cause the engine not to run. To confirm this give it a small shot of ether and get it lit off.

 

I also was playing with the idle **** I'm not realy sure were that is at its getting good spark be back in 5 going to play with mixing screw and see if I have any either in tool box.

 

the first setup you descirbed was really rich so you need to make the pilot smaller and back out the mixture screw some more to lean it out a bit.

 

thinkin 180 main 45pilot and start out on 2 turns out on mix screw I also think I need a new plug

 

ended up with a 180-48 and 3 turns out runs now, I think its still little rich but I'm going to go for some putt runs tomar. and fine tune it I think the first time I just flooded the damn thing with the choke I was all excited and I choked it to start it when its 70f out (dumb ***) thanks to all that replied

 

took for first ride last night as soon as a load hit the motor started popping after 2 min. pipe turned cherry so went to 185-needle clip on first notch and backed mix screw out 4 turns.
got more power still poppin a little and pipe still cherry tomar. we are going to drill some not needed jets out 10-25mm bigger