AIS

[Pappa Bear]

My friend has a 1100 vstar and is looking into blocking off the AIS. It has Cobra exhaust on it but nothing else has been done to it. He says it cracks and pops which I would guess may be common when changing to aftermarket exhaust with less back pressure. Is anyone familiar on the procedure to block the AIS off ? Thanks

[Guest seuadr]

new muffler, more flow, running a little lean, he should consider either ajusting the slides a little richer, if he can, or re-jetting to a slightly richer mixture.

[pegscraper]

My wife rides one of those, and I did it. Even the wife could tell it idles smoother and take off is smoother without it. Simply pull it all off. Twist and pull the fittings out of the heads. Then find a couple empty .45 caliber shells and tap them into the holes. They're a perfect fit. He may want to back the PMS screws out a bit too.

[Pappa Bear]

:doh:I'm not really familiar with his bike yet so what is a PMS screw and slides and where are they? He also has one pipe beginning to discolor, is this a result of the different exhaust or do the carbs need sync? Thanks Ron

[pegscraper]

I think by adjusting the slides, he means shimming the needles in the slides to step them out a little which would make it richer. This would not be my first step however. It was not necessary on my wife's bike.

 

The PMS screws are the pilot mixture screws, or just mixture screws. You will have to remove the carbs and drill out the brass caps over the screws to get to them. Then I can't remember if they must be adjusted on the bench or if they can be reached with the carbs back in the bike. It's been a while since I did this. Start by backing them out 1/4 turn and see what happens.

 

Slightly discolored head pipes don't necessarily mean anything. It's pretty normal. If they're badly discolored, that means the exhaust temperature is too hot, meaning the fuel mixture is too lean. Richen 'em up.