Hi,

Let me just start by saying I know nothing about motorcycle carburetors or jetting. I'm just a guy who loves to ride his bike.

I purchased a 2002 Road Star Silverado about three months ago with 13K now has 15K. The bike came with a Kuryakyn twin velocity air cleaner and Cobra unbaffled exhaust pipes. I don't know much about the history of the bike nor does the guy I bought it from. All of the modifications were made by the original owner. I don't know if the carb has been rejetted but I suspect it has been since overall the bike performs very well. Plenty of pickup and torque. I do get some popping on deceleration.

The issue is once the I get up to speed and let off the throttle the bike starts sputtering. If I pull the choke out slightly is does help. Instead of having a nice smooth ride I find myself constantly having to stay on the throttle. I read through a bunch of threads and can't find anything that exactly matches the issue I'm having.

I've run some Gumout through a tank of gas. Tomorrow I'm going to check the spark plugs. The air filter has been cleaned and oiled. The battery is new. Nothing is really making much of an improvement.

Do you think it could be the coasting enricher. Not sure what that is but some articles I've read online suggest that may be a possible cause.

Someone that knows more the I will chime in here.

It's easy to check to see if it is the coasting enrichener. Usually what happens is the plastic cover cracks with age and exposure to engine heat. Not sure what the air breather you mentioned looks like, but you may have to remove the breather to get a good look at it. It is possible that is causing it.

Halifax N.S. Canada

Father_Pobasturd wrote:
It's easy to check to see if it is the coasting enrichener. Usually what happens is the plastic cover cracks with age and exposure to engine heat. Not sure what the air breather you mentioned looks like, but you may have to remove the breather to get a good look at it. It is possible that is causing it.

I'm assuming Mort posted that pic 'cause it's the Twin Velo. Looks like you should be maybe be able to see the Coasting Enrichening cover with it on. Get some light down there and get your face as close as you can (preferably a cold motor) and see if it has any obvious cracks or pieces missing. If you have even the slightest of mechanical aptitude, you can do this job. Perhaps someone with more computer acumen that I will post a technical drawing of the carburetor so you will know exactly where and what you are looking at. If you have no tools, looks like the most you would have to invest in is a 4 millimeter Allen wrench and a small Phillips screwdriver, available at any car parts store. Good luck and remember the RSC Battle Cry, "You CAN do it"

from Sturgis MI. I'm not a very good carb guy either but this is what you were looking for looks like.

Jlb76 wrote:
from Sturgis MI. I'm not a very good carb guy either but this is what you were looking for looks like. I replaced mine last summer because it was cracked as you can see. If I remember correctly my issues were similar to yours.

Thank you all for advice.

Well it looks like there is a crack in the coasting enricher cover. I'm headed to the dealership to order parts. Going to replace the spring and the diaphragm too. I'll let you know how it works out.

Yea, may as well replace the spring and diaphragm while you are in there. They are likely just as old as the cover and have suffered the deteriorating effects of age. Use caution when you remove it and note the position of the spring. Unfortunately, after all your efforts, your bike will run the same, just without the surging. No performance upgrade will be realized.

The Roadstar motor is pretty bulletproof. Regular oil changes with the most expensive oil you can afford will most likely yield many, many miles of dependable fun. Be sure to read the tech section on oil change and checking the oil before adding or changing the oil. Many bikes have gone in excess of 100K miles, with a few examples passing 200K on stock internals. Enjoy!