7/12 carbs issues

[Heatz]

doing a 7/12 conversion using all the B12 stuff to run the motor but need a base line to start with for the carbs to make it rideable to get it to a dyno 

so far have gone up as far as 150 mains but it eather bogs at anything over tickover unless you give it throttle very slowly then it might make 4k rpm but is not rideable

tryed 130 mains and same thing but if i cover half of the back of the carbs with my hands it revs clean (not under load though)

currently on 122s K&N twin pods with mix screws 1.5 turns out and 70% of pod area taped off it runs/sounds good but wont pull clean under load its ridable but not a pleasant experience  without the tape it crackles n dies back at anything over tickover

ive serched here and via google but getting so many conflicting answers i though id ask the boys in the know

HELP!!!! never had this much hassle with GSXR carbs 

 

Edited February 26, 2019 by Heatz

[dupersunc]

Blocked pilot jets or circuit.

strip carbs and get ultra sonic cleaned.

[Heatz]

3 hours ago, dupersunc said:

Blocked pilot jets or circuit.

strip carbs and get ultra sonic cleaned.

pilot jets are clean and 27.5 did try 32.5s but ran worse engine ran fine b4 it was taken out of the bandit frame

[Oilyspanner]

Your engine is running lean, covering the filters and it runs better proves this. As Duncan says, pilot system and air passageways have to be very clean. Pilot system affects tick-over and gentle cruising, the needle controls the bulk of normal riding - as you've fitted pods, try lifting the needles to make that area richer - if you're on middle clip, go to the bottom position and try that, it should be closer. The main jet only really comes into play at higher revs and with large throttle openings.

It's hard to give good advice from afar, as you have to assume that everything else is working as it should - good spark etc. Hopefully the needle adjustment will help and allow you to run the bike on the dyno 

[Heatz]

ok took a while to get back to this 

after trying every slot on the needles and different mixture screw setting i nearly gave up as was getting nowhere 

opened up the carbs again to move the clip on the needle and just noticed how straight and blunt the needles were compared to others i worked on before

so had a look in my bits box and dug out a set of dynojet tapered needles form a WC1100 that where the same length as the bandit ones put them in with clip one from bottom mix screws 2.5 turns out with 130 mains and woohooo had a bike that finally pulled hard and clean was running well enough that i dont think we even need to dyno it(still gona do it though)

so thanks guys for the help ye kept me on the right track