Switch Vaccum to Gravity Petcock (83 Maxim 750)

You removed the top hat and pulled out the slide diaphram and slide. The needle you took out is for the mains (Jet needle/slide needle), not the pilot.
The plascic cap gets tightnened until it seats. It should be snug enough to not back out. If you overtighten it the cap will crack.

I think that you might have an aftermarket needle. The 750 jet needle has a plastic cap on the needle, and does not have a moveable clip. Is there a number engraved onto the needle? The stock one should read Y-13.

 

Yes they are original, i just took a random picture out of google to show what I was talking about. So just to resume what happened yesterday. I pulled out the carb out and clean everything. I started from the bottom and made my way up. In the bowl, i removed the float valve and float needle, clean the needle again with carb cleaner and where it sit. After that i pulled out both jet, the 43 and the 120 and clean them with carb cleaner (pressurized ) Directly in the hole and after that with pressured air. I did that for every bowl and was looking for any gummed up part. Nothing, it looked like it had just been rebuild since all the part look super clean , when i mean clean i mean MINT.

After i did every bowl i remove every cap on the top of the carb and removed slide, two slide wasnt going all the way down so i polish them with 2000grit sand paper and did a wet sand. After that they were getting back in their position ( Remember, they were working before even without the wet sand) After that i cleaned every port from the top. They are two other ''jet?'' on the top of every carburator, so i sprayed carb cleaner in all of them. After that i reassembled everything and did the bench sync, that was pretty simple and very straight foward. The only thing was that and the end of the ''how to'' that you linked me it said that you need to see a slive of light ( Wtf does that mean ) I mean i was seeing the same amount of light from every carb put hm i was supposed to see? The picture was not that great.

Reinstalled the carb on the bike to see if atleast it would idle.
Bad news, it doesnt even start. Choke at 100% or 0% no difference.
The only way i could start is by holding throttle at 100% and only there it would only run at like 300rpm? Not even? Wtf

I snug every bolt without over torquing them

I think they are 3 reason of why it's doing this :

1 - Idling screw badly adjusted ( Make no sens since if i would go WOT the bike would have start and rev to redline?)
2 - There is carb cleaner in the bowl and now gas is mix with carb cleaner so it can't ignite?
3 - When I re-assemble all the bowl i put the washer under the 120Jet backward (it had a littlel curve), so now the 120jet is sitting 1-2mm lower?

 

4 - And in every scenario, im a complete idiot?

Maybe you guys can see something im missing

 

Many of us have pulled the carb numerous times before we finally got the bike to run right.

If you have doubts about your reassembly you should pull the carbs again and examine each one to ensure identical assembly. Reread the carb clean and tuning section on this site; a few times to make sure you get it right. Consider purchasing a manual with pictures so you have another resource.

Carb cleaner is very flammable and can be used as starter fluid.

Bench syncing is important. Many of us also sync using the vacuum meters. Has to be running before you can sync using that tool. A YICS blocker may help. I've done it with and without with very similar results.

Seating the carburetor on the bike properly is another factor. Bike is very sensitive to air leaks and pressure. Ensure all four carbs are properly seated in their intake boots and air box boots. Ensure vacuum caps are not cracked and are all seated properly.

You mentioned carb parts looking new. Hopefully previous owner purchased the correct carb parts for your bike. Many cheap carb kits out there and I have experienced fit and performance issues with some of that junk.

Ensure your float needles move up and down freely and don't bind. Floats move easily up and down and don't bind.

Patience and trial and error are key to the new owner who doesn't want to pay a mechanic. Careful using the screw drivers and other tools to. Stripping and breaking screws and bolts in these old bikes happens more than you'd like to know.

 

Update :
Try to understand the problem i had (very hard)

Float valve #1 : 17.80mm
Float valve #2 : 17.55mm
Float valve #3 : 21.60mm
Float valve #4 : 18.50mm

Basically thats why the bike was running fine at high rpm but not at low.

 

That'll do it. Glad you sorted it out.
Did you wet-set to get them all even?

 

1 yes 2 no 3no 4no
just turn the idle up a bit and try again, i think you flooded it. when you open the throttle it defeats the choke, when the butterflys are completely closed it sucks gas like a old ford but no air. that's what this is for

 

Hey guys! We did it!
Of course the bike still need few thing
- Exhaust gasket
- Muffler
- A good Carb Sync
And bit of love but we got a idling bike again and working carb without choke!

 

She sounds wonderful and healthy.
Good work.