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Discussion Starter · #1 ·
So We had a full running suz bandit 600, which after changing the tail section over to a bolt on r1 subframe etc, the bike is still "apparently" letting in too much air, as she wont start up properly, her carbs were out on the "pilot screw turns" "Mixture screws", So I set it back to 1 and 3/4 turns out from the seated position,.. anyone got any tips on how to fix this, I think its cause the airbox main opening is more exposed compaired to being housed behind the tail fairing etc on the stock subframe,..But im really hoping theres some easy fix as she was running fine before we started changing the tail section,.. now the revs are up then down then too much air the conks out,.."Banging my head here!"
 

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One of those mystery problems that it seems a lot of the guys have, but there are lots of problem 'experts' on the forum & some of them should be along to help figure this out with you soon. :D
 
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First thing to do id get the bike started even if it needs choke then spray carbs cleaner brake cleaner or hard start under the tank towards the airbox and carbs. If the idle raises you have a vacuum leak which could explain your running super lean problem.

If its not a vacuum leak have you changed your exhaust? air filter?. If its none of those you should check the Owings behind your pilot screws and check you float valves and fuel filter. One thing I always do when I've got my carbs apart is grab the Vaseline off your night stand and put a little bit on the rubber nipple of each of your float valves. It wont hurt you're bike it'll just keep the float valves from sticking. Check your float height while you're at it just to make sure they're right.

If all that doesn't help check your jets and make sure your idle jet main jet are clear and that your slides move smooth and your diaphragms for cracks or pinholes. Also make sure that your carbs are synced.m
 

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Float bowls on those carbs (if they are the stock Mikuni's) are non adjustable, so height shouldn't be a concern. If you have anything other than stock on either side of the engine (headers, slip on, intake filter) make sure you are jetted accordingly. I agree with previous poster about checking for a vacuum leak, including the boots and gaskets.
 
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Discussion Starter · #5 ·
The bike "When it ran" had a gp style can on it and stock air filter and ran fine,... its now got a longet carbon can on it,.. thats the only change other than the subframe conversion,.. hence it being odd that "IF" the bike runs it needs the choke, and even off the choke it dies, on part choke, u rev and it bogs down,.. however when i rolled a cloth up and jammed the airbox main opening it reved fine,....so we assumed it just needed blocking a bit,.. but even so its odd that its doing it when it ran fine before,....I literally have just been told that my bro took out the metal mesh so he could get the airbox rubbers back on the carbs and dint refit it....would this cause this problem???
 
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How long has the bike been sitting since it was last run??Were the carbs drained?Doesnt take long for fuel to go shitty.Sounds like it could be partially plugged pilot jets.Which in turn affects all the carb circuits.
 

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Here is my idea for you. Take the carbs off, clean them thoroughly, check your jetting at that point, reassemble on the bike checking for vacuum leaks at the boots and what not, and after they are on good, balance them.

You are going to end up doing all these steps and damn ways so don't waste time not going in a logical order or trying to diagnose this or that and end up chasing your tail and in the end having to do those steps any ways...

If it still runs like shit after that, well then let's talk :)
 

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I would clean the carbs like F'dup mentioned. The rubber boots not being seal has created a lean situation on one of my previous bikes if not jetted for it(which it wasn't), but the bike never died from it. So, pull carbs, clean them, install them and let us know.
 

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Sounds like ur sucking air somewhere before the air box, Spray wd around the boots at the cyl. side and see if the idle changes ?
 

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Have you figured this out yet?


A good carb clean and syncing should have solved your problems as long as you don't have a bad vacuum leak.
 
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