I'm building a 2003 1600 pretty much from the ground up, currently in pieces in boxes.
Plans & budget don't include any upgrades to the engine itself so it'll be stock.
The bike didn't come with a carb but thanks to the generosity of a fellow forum member I have a nice clean complete carb from a 2006 1700 Roadstar that was sitting around after an upgrade to a Mikuni HSR42.

The carb part numbers between a 1600 & 1700 are only different in the first 3 characters which leads me to believe it's probably the same carb. The model designation where it was originally used is usually those first 3 characters in the OEM part number. The manifolds are the same way, different first-3 with the rest being the same.

Has anyone swapped a newer carb onto an older Roadstar? Anything specific that needs to swap with it? I don't have a manifold for either handy and I'm curious what the real differences are. Any help is appreciated. Thanks

Curt knows what's up with the manifold differences. I think the air jet is different between the 2,carbs, and there was a slight difference on 1600 carbs on Silverados versus the base model, but I can't rember what it was. Txscott I believe pointed out the differences after studying the parts. Betcha it runs fine with the right jets.

Just swap it the bike will never know. There are no differences that will effect anything when installed on your bike just make sure it is jetted for a 1600. 170 main, 37.5 pilot, 4th groove 2 - 2 1/2 turns on the pms

There are a couple internal differences like JD said but put it out of your mind. Those differences won't have any effect on what you are doing. Those are internal carb design things that have been compensated for with other internal carb design changes. Just put it on and enjoy!!!!

Thanks guys. That's kind of what I suspected but I just sell these bikes.
I don't tear them apart to measure things (and the bikes at work aren't mine to play with).

I am kind of curious why there's a $30 difference in price between the manifolds.
* (1600 is the cheaper one)

Yeah, Curt posted the differences in the manifolds once. On the carb, like Dave said, jet it right and put it on. Pretty sure you have to go with the 1600 manifold part number though.

BubbaKahuna wrote:
I am kind of curious why there's a $30 difference in price between the manifolds.


Because they can It don't have to make sense. The only difference is a hair on the mounting holes. They don't cost any more or less to make them due to the difference

My guess is that either motor, 1600 or 1700, would run just as good with either manifold and/or carb, but that the slightest difference only has to do with emissions certification. Am I right, or am I right???

Does a carb from a 1700 perform any different/better than a 1600?

You can use that carb. Not a problem.