400 carbs pls help!

[Mike750]

Hi again to all I'm trying to get a 92 Gsxr 400 started I've tried everything I can think of, first bike would start and drive but dirty , then started it one day wouldn't idle only stay running at high revs with a massive flat spot -bogging standing still, so took off carbs  took apart ultra sonic cleaned them , and got a complete carb rebuild kit all the seals and piolet washers,it had adjustable needles  and 100 mains , screws 1.5 turns out . Got it running again but would never idle and would have to use a lot of choke, so after about five times taking them apart and cleaning  giving them the airline setting floats, I put 115 mains  raised the needles 1 notch and turned the screws out 2.5 turns because of a stubby can aswell thought  still might be starving , now only runs on full choke when starter is engaged  leave off started and cuts out and won't take any throttle  this thing is killing me ! Took lots of carbs apart and put them together again but this one has me melted , pls pls pls any help il be grateful as this is going on weeks now thank you , what am I doin wrong

[Gixer1460]

I assume you have a manual? What are the required stock settings and jets? A stubby can ain't gonna make a massive difference so i'm thinking intake air leak - cracked rubbers being favourite - they may look good when mounted but take them off and little cracks appear. Not saying it'll be that but worth checking.

[Mike750]

The stock settings were 100 mains , screws out 1.5 turns floats were set to manual aswell , not sure on needle size, will take them off again check all and check for cracks in those rubbers, thanks for the reply

[Hawky]

Sounds like a pilot or air leak issue for sure.

Going up 15 on each of the mains is bit to much for just a stubby end can. i would try starting with 105's and mixtures to 1 3/4. 

As gixer1460 suggests check them inlet rubbers but also whip the tops off and check the rubber diaphragms are seated proper along with no cracks/pinholes..

While your at it check fuel tap/vac etc...would still recommend checking them pilots again and size to see if stock etc.