Before I do something stupid...Does anybody know if it's possible to adjust the aim of the accelerator pump nozzle while it is still in the carb? I am thinking about using a pair of needle nose vise grips and trying to rotate the nozzle so that its aim is lower than it already is. My nozzle squirts the fuel right at the throttle valve to the point where the only time it will have a direct path to the intake is when the throttle is opened 1/2 way or more. Small quick throttle inputs completely block the squirt from making it into the intake and I believe it may be the reason my bike backfires through the carb when doing those small quick throttle inputs. I've already tried bigger pilot jets, adjusting the pms screw, needle setting, adjusting timing and duration of acc. pump squirt, float level etc... Any advice or tips would be greatly appreciated, thanks.

The reason your bike backfires while "blipping" the throttle is because you are loading it up with fuel. The slide on a CV (Vacuum slide) carb does not react (open) fast enough to blip. You need more air to enter along with the fuel to keep from backfiring due to loading up with fuel. The nozzle is pressed in and you will likely damage it if you try to move it.

Your Road Star is not a Maserati. It's s a tractor. It has enough torque to pull a stump, but is a shameless pussy at a street light, when throttle play is attempted in an effort to impress the masses.
Like Dave said, if you insist on doing this, your Roadie will continue to spit at you. Something about the dignity of the big cruiser, and it taking umbrage at the teenage twerking.

try adjusting the timing of the acc pump...you can delay the squirt a bit and give the slide a bit of advantage..probably won't eliminate the backfire completely but it can help a good bit.......

SKWEARpeg wrote:
Your Road Star is not a Maserati. It's s a tractor. It has enough torque to pull a stump, but is a shameless pussy at a street light, when throttle play is attempted in an effort to impress the masses.
Like Dave said, if you insist on doing this, your Roadie will continue to spit at you. Something about the dignity of the big cruiser, and it taking umbrage at the teenage twerking.

Flashback wrote:
try adjusting the timing of the acc pump...you can delay the squirt a bit and give the slide a bit of advantage..probably won't eliminate the backfire completely but it can help a good bit.......

Then he will more than likely get a lean pop. You just have to quit blipping or live with it.

davej wrote:
Flashback wrote:
try adjusting the timing of the acc pump...you can delay the squirt a bit and give the slide a bit of advantage..probably won't eliminate the backfire completely but it can help a good bit.......

Then he will more than likely get a lean pop. You just have to quit blipping or live with it.

yep, after re-reading his post I see that he has already tried that..get an hsr and be done with it...

Flashback wrote:
davej wrote:
Flashback wrote:
try adjusting the timing of the acc pump...you can delay the squirt a bit and give the slide a bit of advantage..probably won't eliminate the backfire completely but it can help a good bit.......

Then he will more than likely get a lean pop. You just have to quit blipping or live with it.

yep, after re-reading his post I see that he has already tried that..get an hsr and be done with it...

Thanks for the replys. It feels like I'm chasing a ghost trying to cure this carb backfire and your responses are supporting that feeling, but I know there is something not right. I'm not ready to accept the fact that this is just how these bikes and carburetors are designed. It does the backfire too often and it can happen when I roll on the throttle slowly (all though much less frequently). The fact that I can blip/chop the throttle as fast as I possibly can, let it go back to idle and repeat the process multiple times just to try and induce the backfire with nothing and then sometimes it will happen with each twist repeatedly is just telling me there's something going on that I haven't pin pointed yet. Intermittent gremlins are the toughest to identify and can make many throw in the towel and just live with it, not saying this won't be me eventually...just not yet.

With all this being said I noticed something after coming in from a ride last night. The bike was backfiring a little more often than usual so I removed the air cleaner and noticed that the accelerator pump nozzle was not giving a squirt of fuel. I would twist the throttle and manually work the plunger with nothing, however it would leak fuel around where the nozzle protrudes from the carb body and would give a couple of very weak squirts out the nozzle opening well after releasing the throttle. My guess would be that the plunger is creating the needed pressure for the squirt of fuel but there is a clog somewhere either in the nozzle or in the passage ways between the plunger and the nozzle.

After a few minutes of trying to poke a small object into the nozzle hole (with no success) and working the plunger to try and clear a possible clog the nozzle began squirting fuel as strong as ever. I recently adjusted my acc. pump timing and now with even the slightest twist of the throttle I was getting a good high velocity squirt that would reach the throttle valve. Is it possible that I have a clog somewhere in the acc. pump system that could completely cut off the fuel for a few minutes where no matter what I try I get nothing and then clear itself to the point where it works flawlessly or is there a component beginning to fail? And even more importantly, how do I go about clearing the nozzle or passage ways because of course the one component of the carburetor with the smallest orifice is non-removable...go figure.

Thanks in advance for those of you who are willing to stick with me on this until it gets resolved.