as recommended Ive setup the carb with the 2150 Dyno jet kit and pilot jet tried with 2, 2.5, and 3 turns out
I used the DJ-116 main.
stock air box, stock exhaust, EPA plugged up.
not sure if this stock-ness was taken into account with the recommendation



bike seems to run good while driving and decel
getting some really weird wrong feeling under heavy throttle...almost like I was driving a car with no insufficient motor oil or a misfire.
only when driving, smooth throttle when stationary ...depends on if I drive aggressive or not

noticed that the bike is rich during idle 11.5-7
I also noticed that the bike runs smooth with 2 turns out but then its really hard to start
really confused here dont know jack about carbs and I'm trying to tune it.


Would it be better to start adjusting the fuel screw or the go back to stock pilot?
Maybe the float?
I sense I have certain moments when gets too rich then causes finicky combustion.
idk maybe 2.5-3 turns need an air mod ..it would explain why I needs some throttle to start perfectly.

 

I know we've been through this before, but here it is on the idle set up...

The stock pilot is too lean, even with the stock air box and pipe, they won't really have much effect on idle if at all. Going back is not worth doing.

I cannot remember if I am running the Keihin 40 or the 38, possibly the 40 because we are at about 1000 ft elevation. I forget. Pippin used a 38 pilot at 2400 ft. These are Keihin jets, not Dyno Jet so I don't have any idea if their 38 is the same as Keihin.

The seat-of-the-pants way to adjust the idle screw:

• You are starting at 2.5 turns, a known number, start it up
• once warmed up, turn the mix screw out until the idle drops, this makes the mix richer, counting the turns until the idle drops again.
  • If over 1.5 turns and no idle drop install a richer pilot Plus 2.5 + 1.5 = 4 turns, backing off .75 you are over 3 turns and the spring pressure may not be enough to hold the needle in place.
  • repeat the steps.from the beginning
  • if less than 1.5 turns divide in half and turn it back in that much. It won't be much, maybe only 1 turn.
• if the idle immediately drops turn it in until the idle is highest, then continue turning in until the idle drops
  • if you turn it in more than 1.5 turns it is less than 1 turn out (2.5 - 1.5= 1 turn) the pilot jet should be changed to a size smaller,
  • repeat the steps from the beginning
  • if less than 1.5 turns divide in half and turn it back out that much. It won't be much, maybe only 1 turn. .

This is how it was done in the old days. Finding the point where the carburetion leans out enough to drop idle and the point where the carburetion goes rich enough to drop idle, then splitting the difference. It is best done on a day with average temperatures, 50-70 degrees, since high and low temps will bias the technique to slightly leaner and slightly richer mix respectively.

Sounds complicated, but it isn't It's just turning the idle mix screw. Too far in - too rich, too far out - too lean, meet in the middle.

Anything above idle is likely related to the needle setting and main jet. So your sort of bogging isn't tied to the idle mix circuit unless your heavy throttle is under say 2500 rpm (guesstimate). If your throttle is part way open odds are the idle mix is out of the picture. Find KLXter's thread on jetting with DynoJet stuff. He KNOWS what he is doing with that brass.

 

id need to get a kouba mixture screw to do this.
if I do get the screw to do the tune .. shouldn't I try setting it to the highest first? if I turn it out anymore its going to be way too rich... like I said the meter right now is fluctuating between 11.5-7 for idle
​​​​​to be clear highest is all the way out? or all the way in? or just wherever it is idle the "fastest"?

also what happens when "idle drops" ...what does that indicate? richer, leaner, closer to even ratio?


I think I also need to know what exactly is the difference between the pilot jet and mixture screw?
all I know as of now is simply they affect idle , pilot jet affects low throttle and idle, mixture screw affects off throttle ?



I'm trying to determine a good setup from intuition. but it prob is easier to get the kouba and do your method or this traditional method...
the plan I'm considering for now is..
I think swapping to the 40 jet I bought and turning in on the mixture might work.
if I'm targeting tuning low throttle or idle the
intuition is that a 40 jet will bring more fuel during idle and low throttle(which I think affects starting ability)
...then to make up for the extra fuel leaning the screw maybe 1.5 turns or something less than 2 or maybe 2 ... idk id like to know any flaws with this though





I know thats why I was confused why 2 turns seemed better than 2.5 or 3
im not really even sure if its bogging , its so hard to describe whats happening ...all I know is it doesn't feel right.
maybe I should try to video record whats going on.

 

The pilot jet and idle mixture screw run parallel to each other. The idle mixture screw is used to fine tune the idle mixture only. Just get that adjusted for best idle mixture with the engine warmed up using KLX678's procedure. If you still have the stock needle in the carb, you won't be able to get best throttle response and performance. Go for the Dyno Jet carb kit. Folks on this forum have done all the experimenting and have the answers............take their advice.

Ride on
Brewster

 

How bout this:
Concerning the 2152 kit installed as per instructions for stage 1, AND use of the stock pilot jet, the #38 pilot jet, or the #40 pilot jet -

Nothing about the above is experimental. In fact, nothing about the above can even be called "tuning".. You do it on a properly operating carb, without causing a fault in the carb from the handling, and your bike runs perfectly.
If it doesn't, there is really only 2 things that can be wrong. 1. The instructions were not followed correctly.. 2. A fault in the carb was created by the owner during the kit install session.
This is assuming the bike/carb ran perfectly fine before the kit was installed.. Anyone installing a kit on a faulty carb thinking it'll cure the fault is in for real trouble..

You should read the "CVK34 list of issues....." on my signature line and I'm sure you'll find your problem - eventually..

 

forgot to mention this earlier...
this morning I put the pilot screw at 2.25 turns out
bike started up right away and meter is reading 11.9 - 12.05 at idle... mostly on the 12 side
going to ride the bike and ill see how it goes. if it doesn't work out then ill start trying out someone these recommendations

 

I get that there is this unquestionable research you have ...and I'm not questioning it at all ...in fact thats why I'm confused. and trying to pin point what went wrong.


So I'm on here trying to figure out what mistake I made or something that I might not know about...
fact is the bike isn't running as "promised" ...so I'm asking for help.

were any of the research threads on a bike with stock air flow, and stock exhaust? as well as plugged off EPA stuff and the EPA gas tank tube dangling from the gas tank to the bottom?
I think these are all considerable factors.




but I'm almost 100% I followed the dynojet kit correctly as well as installed all the parts properly.
put the clip in the middle needle groove installed the washers on top ... made sure there was no rips in the vacuum boot installed that ...made sure the needle sit in the main jet hole or whatever its called
removed the pilot and main jet properly .installed not over tightening put it all back together made sure no leaks in the intake boots. did the valve clearances, installed the cam chain tensioner prop, made sure the timing marks were correct at TDC, put a new air filter properly oiled no leak, put a new spark plug gapped within spec. plugged off all the EPA stuff... gas is frequently used never sits and varnishes...

I suggested there might be something wrong with the float but I dont know how to check for that yet.

but hold on to ur horses cause I think I've got my own settings that are working for me...

 

I have taken the advice...and something still may be wrong idk yet.
thats why I'm on here trying to get more advice on maybe what I did wrong or if theres something overlooked and not taken into account or something ...

just want whats best for the bike.

 

{Quick comment relating to hard starting - Read my post in the hard starting thread. I'm betting the float level is just a bit high. Others may say not, but it certainly is worth trying to slightly lower it. You will not run the bowl dry at full throttle and it will not affect any other jetting. If it is too high it may be part of the issue you are dealing with here, but I don't know.}

Now for this thread

Turning the screw in will lean out the mix, turning it out will make it richer. You do not need a Kouba needle. It is easier to use, but if KLXter will either tell where the picture is (I forget) or put it here again he did a trick adjuster screwdriver deal using one of those hex bits you can get for a buck at a hardware store and I think an O-ring. I'm not near my bike right now, but isn't there enough room to reach in from the left side to do idle mix adjustment while running? To use the idle drop process the bike has to be running to hear/feel when the idle starts dropping. So you do need to reach and adjust the needle some way other than around the pipe on the right side. As I said I can't look at my bike right now to see.

As for anything KLXter writes about Dyno Jet, as I tell my students about their worksheets, READ IT ALL. Take your time read it five times carefully word by word. Don't skim and jump into a bunch of questions. Read it, look at your carb, think about it. It takes time to figure things out. It doesn't happen instantly. It takes time to comprehend this stuff. This is NOT an insult to you. It seems it is human nature to read fast then jump and run. I'm just saying read with care and mentally digest everything you are reading.

I think I went through the Marcelino cam timing modification a dozen times before I felt I understood what was being done and how to do it. Same with your starting problems in the other thread. As I read again and again and thought more and more I think there is a point there for your starting issues. Not sure if it plays into this thread though.

 

Here ya go,,