(dhz) Mikuni 30mm carby tuning-where do i start??

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Perthrider

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So ive run my new dhz outlaw (140 zonger) for about three tanks now, and considering it 'run in' i thought id open that throttle, however when i did this, from a low speed in second to flat i was disapointed to find a short lag or 'bog' before it really picked up. this is also relevant when in neutral, when i flick the thottle, it will bog, then pickup. (note this is when the engine is warmed up fully :) ) Also if this is anything interesting, the carb makes a wheezing/sucking sound when you open it up hard-or even just slowly-like its gasping for air? whats up with that?
Ive read NUMEROUS posts about this with people having the same problem with bogging - when opening the throttle or 'flicking it'- all pointing at the carby. but unfortunately im no tuning expert-in fact you may call me 'mechanically retarded'. justi dont know where to start! like with the jet needle c clip? will that fix it? or the fuel mixture screw or the jets or the.. ect ect? can anyone guide me with there much more knoweledgable wisdom on where to start with this? im pretty positive the bike is running rich atm-very black spark plug.
All advice greatly appreciated!
 
THe start is : Throw that thing in the next garbage can and get a decent Mikuni or Keihin or Dellorto with 26mm ;)
 
this may sound stupid but what u can do is record what everything is currently set to then adjust things 1 by 1, if it gets worse then u can always revert it back to where it is now. eg change needle position then check mixture screw, no good try next needle position then mixture screw. rinse repeat. if nothing of all that helps then could be valve clearnces as ppl say they settle in when the bike is being run in and may need adjusting. its all trial and error and personally i find this the best way to learn. couple weeks ago i knew almost nothing about carbies and valve clearances. im no expert now but definately enough to be able to do things myself now
 
ok thanks guys, i dont really want to buy a new carby just yet, just try and make do with what i got. im taking it to a mechanic tommorow and see what he thinks, but if it does come down to it, what iyo is the 'best' carby for this bike? something that wont require TO much maintanence :)
 
I assume the mechanics a freind(no point spending money on something that can't be fixxed)?? Otherwise your probably gonna be throwing away you cash, better to spend the dollars on a OKO....
 
I assume the mechanics a freind(no point spending money on something that can't be fixxed)?? Otherwise your probably gonna be throwing away you cash, better to spend the dollars on a OKO....

"like" :afro:
 
ok thanks guys, i dont really want to buy a new carby just yet, just try and make do with what i got. im taking it to a mechanic tommorow and see what he thinks, but if it does come down to it, what iyo is the 'best' carby for this bike? something that wont require TO much maintanence :)

Your going to need a smaller carbi, ive got a 28mm on a 150 daytona and im running some seriously lean jets , your going to find the 30mm wont even have jets in the sizes you might need to get it close to right.

I'd personally look at getting a PE26 keihin or similar , might be a idea to call DHZ and ask them why they have such a big carbi on the 140 as its impractical .
 
If its the mikuni aka fakuni i had on the 160 its not actually 30mm its an oval bore which measures 26mm ive got a spare 0val bore 30mm here i wanna get rid of if u want it but im pritty sure u have the same carb...
can u get a few close up pics of it ? also find out what jets its running first it could just need the needle postion adjusted ?? maybe go down a few sizes in jetting or first try unscrew the top off the carb pull the slide out and adjust the needle up one.. if its worse go down one also the mixture screw is underneath in a crappy spot after u adjust the needle u might have to dial in the mixture screw.

I wouldnt go to a mechanic its gonna cost u the amount it will be to scrap the fakuni crap and whack an oko flatty on her bud ! And the best way to get it running right is to learn and do it yourself ... Read read and read some more there tons of helpful threads on this site i was like you and hadn't really tuned a carb before until recent and now my oko 26 is running sweet im very happpy with the bike now !

For me its was very hit and miss to begin with but you will get the feel of it after a while and understand more clearly what does what and it will become a breeze to dial in before u know it !
 
Ok thanks guys, Im taking it to my local pit bike dealer who does servicing, who, yes, I do know well, so I have some good deals (always a bonus) and well go through it, ( I have listened to all your recommendations :) ) and see if a oko can be organised as well. Again, thanks for all your help :)
 
Also yeah, it's kind of ridiculous that dhz would do something like that?? There has to be some logic.. Or profit..
 
But does anyone have any ideas on the sucking noise coming from the carby? Is it normal? Could it be since its running so rich?
 

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