Hi Guys,

My "90 model has been running lean, it is very flat off of idle. My buddy and I opened up the Carb bank today and despite the fact that I have a 4 into 1 exhaust system and a Vance and Hines pipe, the pilot jets were the stock #40 which it too small (I bought it this way). The high speed jets are upsized appropriately and the bike runs real well at speed.

So, what is the next size up from a #40 and what is a good source for jets?

Does anybody out there have any jets laying around that might work?

Cheers,

Steve-o

 

I think #42 is the next size up.

If I'm not mistaken, it should be in the 99103 series.
So it SHOULD be PN 99103-42042 for a #42 pilot.

Maybe you could find some cheap online doing searches or call Keihin for advice and maybe a price and availability?

 

Have you tried turning out the pilot screws? Stock on a 90 is 2 and 1/2 turns out. California models are 1 and 1/2. High altitude is just 1/2 out. Denver is high altitude, but I have mine at 2 out. Maybe try 3, or 3 and 1/2 out before replacing the slow jets.

 

OK Guys,

I had my carburetor bank out, and could not find any screw that I could adjust. What is wrong with me? Can someone point me to a pilot screw on my USA 1990 model?

Steve-o

 

Sure, man. The mix screws should be on the bottom of the carbs contained within a tube. Very bottom.
They are generally "D" shaped. You either need a special tool to adjust them, or make your own tool, or dremel a slit on them so they'll take a flathead screwdriver.

 

Thanks for the prompt reply. I apologize for the dumb questions. Do I have to remove the float cover to get to the pilot screw?

There is a screw sticking out of the LH side of the #1 carb (not the float drain screw either). What is that?

Thanks,

Steve-o

 

Nope, you shouldn't have to remove the bowls/float cover to access the pilot screws.

As far as the other screw that isn't the bowl drain..... not sure, really....

 

On the 90's carb's, the pilot screw for the outer carbs are just above the float chamber gasket, at the extreme front of the carb. It should be a common-head screw. Now the pilot screw for number 2 carb is in the same location as number 4 carb. And the screw for number 3 carb is in the same location as number 1. So you adjust numbers 2 and 4 from the right, and numbers 1 and 3 from the left. Oh by the way, numbers 2 and 3 are almost impossible to adjust when the carbs are on the bike, unless you have a very thin, very long screwdriver.

 

Here's a picture of number 4 carb on the right side. The front of the carb is to the right, and the pencil points to the pilot screw, right above the float chamber gasket. Can you believe I have this in my living room?

 

Slowpoke is right. I forgot about the older ones having them on the sides of the carbs.