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Carb tuning questions

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So ive read almost all of the 80 something pages of the 3x3 master thread so I got a fairly good idea about jetting my bike and whatnot but im having some issues and just want some more advice on what to do.

'06 drz400s: 3x3, stock exhaust with end cap removed, stock air filter; jd kit with 155mj, 22.5pj with extended fuel screw, blue needle on fourth position(started off with it in the 3rd, moved it to fourth and not really sure if it helped or not), Elevation between 300'-to 1500' ft. Temps 50-75 degrees (I live in fairbanks alaska)

First off its pretty boggy on take off and my fuel screw doesnt do anything when adjusting it (which means I should go to a smaller pj right?) But I haven't found anybody going to a smaller pj then the stock 22.5?

Second is it seems a bit boggy when doin about 55 in 5th and I romp on it.. should I try a 150mj or maybe move the needle back to 3?

My main knowledge issue is not knowing if its running fat or lean.. I took my airbox cover off and couldnt really tell much of a difference on the low end. Any advice would be greatly appreciated.

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Maybe not relevant but how new/clean is your stock air filter? Looks like youve done your research and your settings seem to be good.

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I have not known anybody that needed smaller than 22.5 pilot.  Personally I like 25 regardless of temp, altitude and mixture screw type. Blue needle sounds right. 155 sounds right.  End cap removed is just a noise maker.  Advise replacing it, it might even run better.

 

About the only way to know rich or lean is to choose a direction (prefer rich) and keep going that way until it gets definitely worse.  Then go the other way.  So I would go to a 160, then do full throttle roll ons in top gear up a hill. Then repeat with 155 and 150.  Keep going until find the best main jet. Then needle adjustments.  Yes it takes time to get spot on.

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There is not much info because not often or ever done.  I agree, the fuel screw adjustment is not always straight forward.  For one thing if the mixture is out of whack far enough so that the idle stop screw is in a long ways to keep it running it may be running of the main circuit more so than the idle circuit.  The only way to know is to look at the throttle opening.  I run a 25 pilot sea level to 10,000 feet and 90 deg F with an aftermarket fuel screw so I can't really think you need a smaller pilot jet in Fairbanks.

 

Check your float level.  Oh and you may need a new float valve O ring.  It could be leaking. 5/16 by 1/16 will work.

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So with the 22.5 pj  you can turn the fuel screw fully in and get no change to idle speed..?

I just can't see it being rich as you live in Alaska...

 replace the muffler end cap as sometimes it's removal can create variants to known settings...

155 main jet, Blue needle clip 3 is where it should be...2.5 to 2.75 turns with 22.5 ext fuel screw

Edited by Craig-o

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Yes I can screw it all the way in and nothing happens. I turned the idle down as much as I could get it before adjusting and still nothing changed.

As far as the muffler goes.. I really don't see how the end cap could play any difference in the tuning.. its all in the header and maybe the baffles.. but the s/a? Would it really affect it that much?

That's the set up I had. I'll switch it back to the 3rd clip and run it. Maybe itll crisp it up. And maybe try the 25 just for the hell of it.

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Ya maybe with my colder temps im running a bit lean and could bump it up to a 160? Seaing as how removing the airbox cover didnt really help. and the pj is maybe to small and im just not turning it out enough? ?

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