Hi all, I just installed a K&N RC-1980 air filter with existing unmarked after market exhaust. I rejetted the carb with a barons kit 170 main, clip on the 4th groove from blunt end, and washers installed as indicated on the directions and how they were on the existing needle. I tested this with the PMS at 2, 2.5, and 3 turns out. AIS is removed, and the port is capped on the manifold. I tested for air leaks around the carb and everything is fine.

I would like to fine tune to get rid of the vibration at mid throttle, or cruising speed of 50-55 in 4th, and 65 in 5th. I also experience a slight stutter at low rpms in gear like making a turn in 2nd. I can kick it down to 1st and be fine. Both of these seem a little worse after the install and rejet. The vibrations stay when I pull the clutch lever in and throttle at same position. The vibration go away when I roll off the throttle.

I searched and read many posts, but all that did was give me conflicting information. I seek the advice of the experts to tell me what direction I should go to help clear up these two issues. I am aware that vibrations are expected, and the whole harmonics thing, but it makes my fingers numb. I was able to tune my V-Star to run with minimal vibration at my desired cruising speeds, so I was hoping to do the same with this.

Man it sounds like you are pretty much there. Maybe run a good fuel system cleaner thru it seafoam might help with the stutter. As far as vibes go there's a good difference between the Vstar and your road*

The vibration may just be the harmonics of the engine at that rpm.
I changed my pilot to a 37.5, and I have turned the duration screw down some on the accelerator pump. The pilot cured the chuff(stutter?) in the intake. The duration screw adjustment smoothed out the throttle response.

+1 on the accelerator pump screw. I have a 37.5 pilot also and an adjustment to the accelerator pump cleared my low rpm burp.

I know there is a difference, but before I jetted the Roadie was much smoother than my V-Star at 65. Anything above 55 the V-Star hum, but I got the humming to a minimum to make it as pleasant as possible on the highway. I don't remember exactly what I did. I am hoping some fine tuning can get the vibes reduced at those rpms. I am hoping someone experienced this as well and knows exactly what is causing it, or what direction I should go, so I can save taking the carb out a few times.

Thanks! I will give the 37.5 and accelerator pump a try.

dshingler wrote:
Thanks! I will give the 37.5 and accelerator pump a try.

Here's a link to the accelerator pump adjustments.
http://roadstarclinic.com/content/view/63/96/

I tried the nut underneath and the screw tight to the stop. Then the nut back on top with the screw 1 1/2 turns off the nut. Now, I'm at 2 1/2 turns off the nut.

With the 37.5, put the PMS back to 2 1/2 out to start. You can adjust it in or out later.
Sorry I couldn't be more help on the vibration.

No problem, I will get it figured out.

Where did you get the 37.5? I am having trouble finding it online, and nobody around here has one. The local Yamaha dealer said they don't make the 1/2 sizes above a certain size. Thanks.

Mine came in a kit that I actually purchased by mistake(I'd asked for a carb rebuild kit). It was sold under the name of "Factory Pro" for the 1600 Road Star. I'd already ordered the Barons.
I wouldn't have used it, but I had the PMS way out to try and find a rich stumble, and it just wasn't there. At 3.5 out, I got the chuff sound shifting for corners, and after doing some reading, and on the advice of several members here I went ahead and put it in.

Here is a link that Curt uses for Mikuni jets.

http://www.pjmotorsports.com/mikuni-jets.html