Carbs need cleaning?

[ddnova]

I have an 86 GSx750s (pop-up), but for sake of argument we will refer to it as an 85, it has the MikuniBS32ss carbs on it. I recently had it out at highway speed when I it kinda spit and sputtered, I flipped the fuel cock over to reserve and it took me home. It has'nt run right since, what I found was the #1 header pipe is touchable after running the bike for about 20 seconds yet the #2,3 and 4 pipes are hot . I removed the carbs and cleaned them to a certain degree (did not tottaly dismantle) but still nothing from the #1. I checked both coils, valves, compression, cam lobes, spark control unit,and replaced the plugs with new ones (spark at all four cylinders), everything was within spec but still nothing from the #1. When I run the bike and cover the #1 carb inlet the fuel of course backs up , then I uncover it and the fuel gets sucked in and the pipe warms for that short instance. Do I need to dismantle the carbs completey and clean them or could it be something else? Will a dynojet kit help? The carbs right now are stock with a kerker 4:1 and a K & N filter. Also the small screws on the tope of the carb outlet side , what are they for and what should they be set at.


Any help is greatly appreciated,
Thanks

 

[Mark whiz]

I think you're definitely on the right track with the carbs. Really, the only problem the ignition system might have is either a plug or plug wire to the #1, since the #4 is ok and they share the same coil. I doubt you need to dismantle the entire bank of carbs, just each one individually - which means you need to take out all of the jets and clean them and all the orifices in the carb body with a carb cleaner and/or compressed air. I would also replace the float needles if not both the needles and seats as well since they are about the only "wear" type item in the carb.

Since the bike already has a 4 into 1 and a K&N, you might want to up the size on the main jet just a little bit while you have it apart - but don't take it up too much..... as you want to know what the cleaning did to help before you worry about getting the jetting "just right".

The screws you see on the head side of the carbs is the low speed idle adjustment. They control how much fuel flows thru the pilot idle circuit. Typically they should be about 2 to 2.5 turns out from fully closed for best results.

 

[SqDancerLynn1]

I would bet you had some crap in the bottom of the tank. When you puit it on reserve the crap got into the carbs. You need to dissemble them & clean them. Screw is mixture (air) about 2-2.5 turns out

 

[motocycle shawn]

carbs

carbs

i had this when i got my bike!! i put new plugs and cleaned the carb on the #1 cycl. i had crap in the float valve... and main jet..
good look hope you get it.