Thanks for this great site. I have owned Roadstars since 2000 when I bought my 1600 and now I have a 2004 I purchased from a friend. My problem is at low speeds(betweed about 15mph and 45mph) in second or third gear it sputters if I hold the throddle steady. I runs great at highway speed and gets about 45mpg. It does have some carb fart at times, but it does'nt seem too bad. It is stock with the exception of V&H pipes with no re-jetting. I was told it could be SVS so I used Yamalube ring free and have not seen a change.....Any help would be appreciated...thanks and keep up the great site

Might have a pc of dirt/debris partially clogging the pilot curcuit.

Could be the change from winter to summer gas, try just adjusting the PMS first and see if that helps. BTW

is this issue that just started? if it is carb related it would be in the pilot ckt at those speeds. Have you checked the resistors in the spark plug boots? Is the AIS removed? If so, is the manifold vacuum ported sealed? Have you checked for manifold leaks? Starter fluid works great, will find the smallest of leaks.

Still has AIS...How do you test the resistors and please tell me about the starter fluid test....thanks, Don

the boots unscrew off the wires, just test from each end, they should be 10k ohms plus/minus 10%. if you look in the boot, see a panhead screw, a spring, resistor and a small metal disc is in there, as an option you can replace the resistor with a piece of 6ga wire.

Just spray around the manifold to head joints, just be sure to not get any in thru filter or you will get a false read, any change in rpm is an indication of a leak

Thanks so much...I will try those tips...Ride safe and thanks again

Was it running rough when your friend owned/rode it?
Was it run recently before you bought it or in storage?

Ray

He said it was running ok. He bought a new bike about a year ago and rode this one very little....so it sat up without being ridden much. I got the bike a month ago and the more I ride it the better it seems to run. I has always run good at hwy speeds, but when I first got the bike it ran poorly at idle(lots of coughing through the carb). I used seafoam on the first 3 tanks and then put the ring free in for the next 3 tanks. I'm using 87 gas and I'm thinking its an easy fix for someone mechanicaly inclined, but thats not me. I have read for hours and hours the posts on this site and tried to fix the problem myself. I'm getting close. When I can find and adjust the PMS I may fix the problem. I took the air filter off and can see the carb. and was told the air mixture screw on the bottom left can be adjusted, but can't fine the setting and wont touch it until someone tells me the settings. I also would love to find the PMS adjustment

the pms screw has to be exposed in order to adjust it.. read the many tech articles here and you will see where it is..