Topic: #2 running rich

[cd811]

all my plugs look good except#2...compression good...float height right with new valve n seat...new jets(main and pilot)...the plug is black...fuel not oil...motor runs good but if #2 was right it would be even better...scratching my head in ms.

[TwoTired]

Your carbs also have air jets, which, if restricted will make the mix richer.

Both the slow circuit and the throttle valve have emulsion tubes that are fed from the air jets.  These cross drilled holes must also be clear. And, the holes placement and size must be the same as the other carbs.  (You don't mention any history of internal parts changes, which can also be a major clue to your "rich" cylinder.

A hung or unsynchronized choke butterfly can contribute.

If pod filters, uneven restriction across the carb bank.

Carb synch?
Valve adjustments?
Rounded cam lobes?

You didn't give us much history so these are guesses and info.  Perhaps we can expect some cheese with future whine?

Cheers,

[cd811]

well I assumed(that is where I messed up...lol) that you were familiar with a lot of my history since most of it has been posted...what kind of history do ya need?...it's a fairly new up running project...the carbs were built out of 2 or 3 sets to make a decent set...there is a breadbox...like I said new jets, and new valves and seats...the emulsion tube that you mentioned...the  main jet is on top of it?...if so, it is clean...teach me about these air jets...what about these hung or synching choke butterfly...it has been a while since my carbs where synced...I'm expecting a new carb sync tool this week....valve adj-OK...when I built the engine ,I had a pile of cams and I picked the best looking one...cheese and whine???...stupid me....humor that I don't get

[cd811]

well I got my new sync tool in this week(4 gauges) and put it to work...carbs seemed to be way off from my last sync(6 month's ago)...bike runs great...also rechecked valve adj(many too loose, one too tight)...checked choked sync,all clear...will check #2 plug again soon...thanks for all the help

[scondon]

the carbs were built out of 2 or 3 sets to make a decent set

   The airjets are at the rear of the throttle body where the airbox attaches. There is one on each side, one for main jet one for slow jet. Their purpose is to mix air with the fuel in the emulsion tubes before it enters the throttle body. Different carbs have different size airjets. If you used different single carbs from different years you may have mixed air jet sizes.

[cd811]

yea I thought about that after I wrote that...thanks...If I remember right ,the 4 main bodies were all from one set....when I eyeballed my choke flaps, I also looked at the air jets,they all look clean and undamaged...any other way I can check my air screw to make sure they are OK?....I guess I could pull bowls ,then squirt carb cleaner through air jets??

[scondon]

I guess I could pull bowls ,then squirt carb cleaner through air jets??

That's what I do.

    I set the airscrews by turning them all out 2 turns then,one by one, I'll turn them in a 1/4 turn at a time. Engine idle will increase slightly and then begin to drop down as the screw is turned in. I get it to the point that it starts to drop down then back it out 1/4 to 1/2 turn. Using this method I have three screws set at 1/2 turn out and one screw set at 1 1/2 turns out.Engine runs better than when I had them all set the same. Maybe you can try this method with your #2.

   Did you check the needle clip position on each carb when you put the set together?

[cd811]

yea...I started the clips at second from bottom, but since then moved them to the middle...the needles were used, so I was thinking there might be so wear there(like on #2)