Screaming eagle question regarding mikuni carbs...

the*bear · #1 03-01-2008, 11:35 AM

Hi guys,

I posted this in the general forum, but perhaps someone here has a similar carb set up on their screaming eagle that can give me some pointers. Here is the situation:

I am sure I have Mikuni carbs (x2). These are mounted on an intake that has the name "Rivera" stamped into it. They have velocity stacks on them. The previous owner was playing around with primary jet sizes, etc, and right now the bike runs waaaay rich at open throttle (the one time I actually heard and saw it run - currently it does not start, but that could just be the cold? In addition when I saw it run it would not idle. Again possibly the cold.

The question is how do I identify first what model of carbs these are, and then what the "base" size needle and jet would be for whatever model carbs I have?I suspect I should be able to find this information online. I realize they may have to be adjusted for all the bolt ons, but I need to establish a base line somehow and then begin modifying the jets/needles accordingly - again. The bike did come with a jet "kit" with half a dozen needles, primary jets, etc. I have no idea at this point what should be in there.

In addition, there appears to be a slide on the rear of the outside (left, if viewed from the front) carb that might be the choke? It doesn't appear to communicate with the other carb however. It appears to activatesome kind of plunger on the back of that carb, when slid back and forth. If anyone can answer that mystery, I might be further along in starting this thing. I will include a photo that shows the carb setup, however if more close up photo of anything is needed for clarification, please let me know.

Thanks!

Scott

Fireman44 · #2 03-01-2008, 09:17 PM

Unless you have a monster cube engine two carbs is one too many. There should be a # on the needle and the jet telling what size it is. Mikuni should be on the carb, you can check there web for more info on what it is. You might be better off getting a new intake manifold for a single carb. You can make a duel carb work under perfect conditions, as you see there are not many days that are perfect conditions. The choke is on the back of the carb (i think)

Puzzled · #3 03-17-2008, 06:39 PM

If you haven't got it yet I can dig out a number for Lee Chapin at Mikuni. Lee has dialed in my last two sets of dual Mikunis on my 113" and 124".