DHZ Duel Exhaust

Discussion in 'Tech Reviews' started by steeny, Jun 2, 2009.

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  1. Jun 2, 2009 #1

    steeny

    steeny

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    Gday all i am brand new to the forum so i thought that i would give a review on my recently purchase DHZ duel exhausts.

    i have a DHZ 140cc 2008 model that i have flogged over the past year and suprisingly had very few and only minor issues with the bike, mainly from owner abuse any way.

    I managed to drop in to the DHZ shop while up in sydney and pick up the duel exhaust for about $270. Itching to fit it all up i went to work as soon as i got home removing all the existing and fitting it up.

    The first issue was that when i had bolted the header pipe on and was installing the bracket to hold the additional muffler. With the short mufflers i could not get the bracket far enough fowards the front of the bike on the designed mount to hold the muffler. I went to work altering the bracket and then the plastic block that holds the seat down with succsess. From what i have seen this many not be an issue on the 2009 model bikes.

    The Second issue i had was the mufflers only slid over the exhaust pipe with no clamps or sleve as such. One muffler fitted snug although the other was to loose on the pipe. No big issue i just used some high temp silicon to seal the mufller over the pipe.

    Finally the only other thing that i struggled with was the re-tuning of the carby. As i had not done this before it turned out to be a lenghty process in which i still have not resolved completly. I am still working through that to get the most out of the bike.

    This past weekend i managed to go for a bit of a ride. After many races with my riding partner it seems that the bike is running a little slower. :mad:
    In saying that the carby is not yet right, there seems to be a little surging and spluttering going on when i really open it up. i will let you all know how it goes when i get this right

    As for the exhaust note, i love it:D the stainless steel pipes give it a deeper sound that is louder that the big bore mufflers. SO i am stoked with that

    Oh well i will update when i get the bike running well. Please ask any question as i will do my best to help anyone.
    Cheers
    Photos are attached somewhere???:confused: i hope
     

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  2. Jun 2, 2009 #2

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    Welcome to the site mate ,

    I was told they foul on the shock reservoir and you need to have remote reservoir ?? can't really see in pics but does your shock have a reservoir at all ... and if not is that how it came ?

    Have you jumped it yet ?
     
  3. Jun 2, 2009 #3

    pbk

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    im curious to know would it make it quiter because it has two pipes and the air can escape quicker half way ao therefore releasing a little bit of air out of each exhaust?
     
  4. Jun 2, 2009 #4

    mattbombers

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    heey pit bike kid the order is in an on its way, but the frame is costing a fortune to post coz the wieght ya rekon you can throw in another 20 or so? cheers
     
  5. Jun 2, 2009 #5

    Shing

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    The noise you hear from the exhaust isnt always the compression of air. The compression of the air might alter the pitch of the exhaust. But the noise your hearing is what you get when petrol explodes :p

    I'm not saying that the compression of air doesnt make any noise, but rather that its only one factor effecting the noise.
     
  6. Jun 2, 2009 #6

    headsmess

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    no, the noise ISNT the explosion of a petrol air mix but is the SHOCKWAVE caused by the opening of a valve releasing a mixture of nitrogen co2 h2o and co(a burnt air/petrol mix) that is hot and expanding quickly. if you have petrol exploding in your exhaust, somethings seriously wrong:p

    the duals slightly lessen the shockwave by dispersing it through two pipes instead of one...larger surface area=less pressure=less of a shockwave

    but damn, at 270, why bother? looks sick, but.....
     
  7. Jun 2, 2009 #7

    Shing

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    Haha. Thats what i meant. I just CBF typing it all. Point is, petrol exploding in internal combustion motors = noise! :p
     
  8. Jun 2, 2009 #8

    steeny

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    Yeah have been told that the exhaust hits the resivour as for the remote resivour i am unsure. The bike came with that shock and holds up the the jumps well. i am not the biggest bloke but i am jumping all the time. It perform really well on the whoops too.
    The shock is a fastace 1000 Ilb spring. i think it must be an internal resivour?? are the remove resivour shocks a heap better??

    As for the sound of the pipe it is a little louder, mainly a deeper pitch.
     
    Last edited: Jun 2, 2009
  9. Jun 2, 2009 #9

    zaffa86

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    Looks rad but think I may stick to the FMF!
     
  10. Jun 2, 2009 #10

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    Don't think you have one at all ... but yeah they arebetter with one remote or otherwise .... if you upgrade you'll need a remote one
     
  11. Jun 2, 2009 #11

    coolmodee01

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    i find it funny

    we've spent the last couple of year haveing kids ask how can i make my bike louder so i can be cool

    now this twin pipe junket is going to make bikes quieter if ya can get em to work

    jetting will be a nightmare

    but i can see benifet the yx160 with the tb super head thing is the loudest bike out so twin zorst might be a go but cant mount em on our bikes i dont think

    funny ha
     
  12. Jun 2, 2009 #12

    pbk

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    welli just want a quiter bike the neigbours would quit whining
     
  13. Jun 2, 2009 #13

    Peter1230

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    30 dollar silencer off ebay.. give it a go liam lol
     
  14. Jun 2, 2009 #14

    steeny

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    Yeah your not wrong there. i am having fun with the mixtures. have almost got it right but it has been a bit of an effort. Spent 3 afternoons on it last week. bit more to go to get it nice and crisp. When i started out and it was shooting blue flames 6 inches out the pipes. :p
     
  15. Jun 2, 2009 #15

    steeny

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    Will look into it i think they are about 200 bucks for the fast ace with a seperate resivour
     
  16. Jun 3, 2009 #16

    rumble

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    what have you done to the jetting and carb. looking at doing an exhaust upgrade soon.
    My guess is the jets need to be larger??
     
  17. Jun 3, 2009 #17

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    I'd wait and see how he goes with it ... sounds harder to tune than a harp
     
  18. Jun 3, 2009 #18

    headsmess

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    flames out of the exhaust?:eek: check the valve clearance before anything else then...
     
  19. Jun 3, 2009 #19

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    Good catch headmess I totally missed that :eek:

    He's right check it before ya wreck it :cool:
     
  20. Jun 3, 2009 #20

    steeny

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    When i put the header pipe on it didnt tighten it up enough ( to squish into the metal gasket peice) so there was major back flow issues. Once i fixed that up there was no flames. I had not though of checking the valve clearence, What sort of clearence should i be aiming for???
    thanks boys

    Have just been adjusting the air/fuel mixture at this stage. It is deffinatly getting close, It is my first time making major carby adjustments so it is taking a bit longer. Will be getting some help i think of a mate. i am finding that it is running to lean so i am feeding the fuel into it. Might even take it to my mechanic to get it sorted out. i will let you know the GO when i get it sorted.
     

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