Right cylinder cutting out

[jamaha51]

I just got a banshee on a trade the other day.  The right cylinder would cut out when it hit the powerband so I started checking it out.  The tors has been cut out, the cylinders are within 3 psi of eachother, switched sparkplug wires,  and the reeds are decent (a couple pedals have a tiny gap).  I went through the carbs and adjusted the throttle cable so its even.  Its all stock besides the pipes and no airbox.  After I went through it i did a couple 1st through 6th passes up the street and it seemed to run good.  I shut it off for a few minutes then fired it back up and it started cutting out and it just got worse the more i ran it.  So go back out this morning and its still cutting out bad.  So i check the plug gap (running br8es'), adjust the airscrews and the idle and it ran better but still cut out at high rpms.  I do a plug chop(plugs were a nice brown) and switch the plugs.  Doesnt seem to help.  Its really starting to frustrate me cuz it will run ok one minute then cut out the next.  Im thinking airleak but im not really sure?

[Surfrjag]

check airleak and jets in the carbs while its apart. I have seen to many times the main jet fall out..

[jamaha51]

The mains were both tight when i went through it yesterday.  Will double check though

[jamaha51]

So did a leak down test and it held 6.5psi steady.  So now I have no idea what it might be.  Any input?

[salmon_slayer06]

could have a wire rubbing somewhere, its grounding out .

[Juss11]

You didn't get the float bowls switched when you had the carbs off?

[jamaha51]

I looked but didnt see any issues with the wiring.  I didnt switch the float bowls but what would that do?

[Juss11]

Its been along time since I messed with stock banshee carbs, but from what I remember one of the float bowls has a little jet in it for the carb with the choke. If its on the wrong side it will run like shit. Try searching in the forms

[Zillaguy]

The left carb has a small brass BB peened into the bowl... ONLY the left carb has this...

[jamaha51]

Thanks!  I will look into that tomorrow.

[Pastrykiller]

The left carb has a small brass BB peened into the bowl... ONLY the left carb has this...

Not on the 87 and 89 that I own. Both bowls look the same from the outside. Some setups have brass tubes in both bowls as well. what you need to look for is the little indent in front of the brass tube. one indent is open and the other bowl will have the same indent but its plugged by the casting. the indent that is open will be the left carb bowl and the plugged indent is the right side.

 

The choke works by pulling fuel into the brass tube via the open indent and transferring it to the right carb via the rubber choke tube that people forget to install.

[Pastrykiller]

Photo of the BB in the float bowel.

 

Indent/hole that fuel is sucked into the brass tube.

 

Right side bowel has identical indent/hole. You need to shine a light into it to see which one is open. No light? That's okay. Just suck on each brass tube until you find the one that doesn't have resistance and that's the left side bowel.

[Pastrykiller]

Once you pass out from sucking on the brass tube, you will realize that sarcasm was used. The brass tube that fuel is pulled thru is actually in the carb body and not the one in the bowl. Shine your light into it and look for the difference is castings.

[jamaha51]

For other people reading this thread it ended up being a bad stator. Replaced the stator and ran great, thanks for all the help.

[trickedcarbine]

Nice. Another follow up.