MidStar07 wrote:
Re: the 1700's being jetted rich: I disagree. Mine was very lean. I think the reason the jets end up smaller after jet kits are installed is because the needle that comes with the kit is so much more tapered (richer).

Ok Guys... Admit it. You're conspiring to make me think that I'm loosing my mind. And there may not be much to loose!

When I got my Roadie someone had already been in it so I never worked with the carb stock and had to go by the info I got here. 6-8 months ago when I was elbow deep in working on the jetting on my bike, I remembered reading many comments that our bikes were jetted too rich from the factory and it could also possibly be part of the SVS issue. I just did a search, to be sure that I wasn't having a RSW (Remember stuff wrong) issue, and found some of those threads were from Curt and Sobacracker and no one ever disagreed. In fact I had never seen anyone mention stock bikes being lean till now.

So my thinking now is that both could be correct. It seems that between the float level possibly being off and/or the PMS adjusted wrong a new bike could be jetted right but still be running rich or lean.

You got it....it can be both. That explains the AIS everybody throws away. The AIS pumps fresh air into the motor (after combustion)in an attempt to lean it out to make the EPA happy with the numbers. The jetting need not be messed with - with aftermarket exhaust because it is getting enough fuel already. It's when you mess with air intake and exhaust that you have to make changes. Clear as mud? Good , now you can find your marble and stick it back in. BB

Do it yourself and save some cash. The tech articles are very good and if you do a search in the forum you can probably find someone with a similar setup and get some jetting start points. It can be fun too!

BigBoyinMS wrote:
Hey Chico, let me make a couple of comments.

If the dealer did... or ever does... mess with the jetting on your bike then it's probably not correct. Most will use the recommended jets and settings from the instructions that come with the jet kit. And they always seem to be too rich. Or the tech will see what jet is in it and go up a size or two.
Every now and then someone here will mention a dealer that got it right.

I'll also mention one other thing. From all of the reading that I have done on here and noting everyones final jetting, it seems that the 1700 bikes come too rich from the factory. Even after new pipes, BAK and porting the manifold, most end up with a smaller main jet than came in the carb.

But the best advice i can give you is read, read, read all the tech info here. Then you can at least know what to look for as far as running after someone else has been in your carb.

Good Luck!


There is an important item not mentioned in the above post. Yes, after all the changes most RS end up with a smaller main jet BUT among those changes is also a new jet needle - this new needle is smaller (profile view) than the stock needle and lets more gas through. If you add airflow in and out you need an aftermarket jet needle.

Chaplain Charlie wrote:
Normally more air means more gas and a bigger jet, but the thinner needle gives you much more gas so you the jet has to go down.

That is true for 04 and later. 99-03 have a 165 main, and it often needs to go up (larger) for aftermarket air and exhaust. Just fyi.

The profile of the needle didn't change for the 04's with the larger displacement. I think Yamaha chose to just increase the main to force more fuel by with that fat stocker that was designed to pass EPA testing.

Gram

The 1600's had a 165 main.

Musky wrote:
The 1600's had a 165 main.

oops

EDIT NOTE: Fixed my post.