Hey guys I'm new to the forum, and to road stars. Got my bike a few weeks back, it's an 03 Silverado 1600. The bike had sat for a couple years and wasn't running very well, if at all. I negotiated a very good deal and brought her home, pulled the carb, cleaned the jets and put it back together. It ran a lot better but still wasn't right. So out the carb came again and I took it completely apart and cleaned everything. Put it back together and it is running pretty good but still not like it should. A little doggy and I'm getting some popping and backfiring. Also if I'm coasting around 40 I get some studdering and poppingI've been adjusting the pms about 1/4 turn at a time. It doesn't seem to make much difference either way.

Bike has what I believe are cobra slipo on, stock air box stock 165 main, 35 pilot, needle clip is on 3rd ring. Pms is 3 1/2 turns out. As far as I know everything else is stock. My thinking is to start with measuring the float bowl level first And go from there. I'm looking for sujestions or advice. Thanks a lot guys.

Yes float did u blow put carb with air or clear all passageways

brianmac wrote:
Yes float did u blow put carb with air or clear all passageways

Yes I did blow it out. Sprayed it down good with carb cleaner, and blew air anywhere I could.

Agroomes1 wrote:
Hey guys I'm new to the forum, and to road stars. Got my bike a few weeks back, it's an 03 Silverado 1600. The bike had sat for a couple years and wasn't running very well, if at all. I negotiated a very good deal and brought her home, pulled the carb, cleaned the jets and put it back together. It ran a lot better but still wasn't right. So out the carb came again and I took it completely apart and cleaned everything. Put it back together and it is running pretty good but still not like it should. A little doggy and I'm getting some popping and backfiring. Also if I'm coasting around 40 I get some studdering and poppingI've been adjusting the pms about 1/4 turn at a time. It doesn't seem to make much difference either way.

Bike has what I believe are cobra slipo on, stock air box stock 165 main, 35 pilot, needle clip is on 3rd ring. Pms is 3 1/2 turns out. As far as I know everything else is stock. My thinking is to start with measuring the float bowl level first And go from there. I'm looking for sujestions or advice. Thanks a lot guys.
when I had my 1600 I ran 35 pilot 172.5 main, needle on 4th, pms 2 or 2.5 turns.
sounds like you may have something that is still not cleaned out. (remember there is also an air jet in the top of the carb under the boot)
Possible you could have an air leak somewhere as well

We assume you cleaned out the fuel tank, pump, filter, etc. Run some Seafoam through it.

First off Cobra slip on mufflers are junk and have a tendency to pop on decel. Are you running a K/N type air filter? if so you are running lean thru all the ranges you should be running a 170 Mikuni main jet, 37.5 pilot jet and the clip in the 4th groove on the needle with a plastic spacer and 1 washer under the clip and the pms should be set at 2 1/4 - 2 1/2 turns out.

The symptoms you describe wouldn't be caused by incorrect float level. You go bending on that float tang, you're just asking for trouble. 9 outta 10 times people adjust the float, it didn't need to be adjusted. There's no way the float can be bent out of shape unless someone got in there and fued with it already. Does your bike retain the A.I.S. system? That could be the source of popping on decel.

davej wrote:
First off Cobra slip on mufflers are junk and have a tendency to pop on decel. Are you running a K/N type air filter? if so you are running lean thru all the ranges you should be running a 170 Mikuni main jet, 37.5 pilot jet and the clip in the 4th groove on the needle with a plastic spacer and 1 washer under the clip and the pms should be set at 2 1/4 - 2 1/2 turns out. Dave could you be more specific? Damn you're good.

davej wrote:
First off Cobra slip on mufflers are junk and have a tendency to pop on decel. Are you running a K/N type air filter? if so you are running lean thru all the ranges you should be running a 170 Mikuni main jet, 37.5 pilot jet and the clip in the 4th groove on the needle with a plastic spacer and 1 washer under the clip and the pms should be set at 2 1/4 - 2 1/2 turns out.



Get rid of the Slip ons... and then work from there. Those things are junk. Been there done that!

Don't forget to give the intake manifold a look. These have been known for cracking and getting an air leak.