ZXR250 Exaust Debaffling & Cam chain

[cheetor]

Hey, 2 things here. first of all,
anyone debaffled their exaust., it looks rather tricky for the ZXR and advice would be appreciated

I've started to notice a ticking in my engine, seems to be cvoming from the head, I'm not sure if its valve clearances or a cam chain, I'm just coming up to 20,000K on the bike?


Oh, and anyone know hot to stop forks leaking?

[John]

1) Dont debaffle it, tristanK did and lost lots of low end - If your going to do it just smash a few holes in it thats what I did, I havent lost any low/mid range
2) Could be alot of things take it for a checkup - chain probably needs a tighten, valves have probably never being touched.
3) If your forks are leaking take it to a mechanic the process is abit complicated, you do mean its leaking 'oil' out over the chrome slider huh? either way throw it nicely at the mechanic.

[250learna]

1) Dont debaffle it, tristanK did and lost lots of low end - If your going to do it just smash a few holes in it thats what I did, I havent lost any low/mid range
2) Could be alot of things take it for a checkup - chain probably needs a tighten, valves have probably never being touched.
3) If your forks are leaking take it to a mechanic the process is abit complicated, you do mean its leaking 'oil' out over the chrome slider huh? either way throw it nicely at the mechanic.

How much did he gain in the top end?
And did you gain much other than noise?

[John]

How much did he gain in the top end?
And did you gain much other than noise?
would it really matter maybe 2-5kmph, its a 250 - it wont see past 180 in its life time

[250learna]

would it really matter maybe 2-5kmph, its a 250 - it wont see past 180 in its life time

no worries, just curious :niceone:

[cheetor]

1) Dont debaffle it, tristanK did and lost lots of low end - If your going to do it just smash a few holes in it thats what I did, I havent lost any low/mid range
2) Could be alot of things take it for a checkup - chain probably needs a tighten, valves have probably never being touched.
3) If your forks are leaking take it to a mechanic the process is abit complicated, you do mean its leaking 'oil' out over the chrome slider huh? either way throw it nicely at the mechanic.

Well Its gonna be rather simple for me to do most of the work myself, hell while I have the engine apart I might as well do the bearings too.

as for the exaust, Noise I need :) so I'm not too worried about the low end

ightened the chain myself, got some good oil for it too :)

[aff-man]

okey couple of things
1) it is the cam chain , they are notoriuos for going on the zxr's mine did.
2) debaffling although looseing low end you gain a bit of high end.... and if you are riding in the low end where losses are made you shouldn't be riding a zxr , they are built to squeal as i found out. Changing gear at about 12k revs makes it so much smooother riding.I had a straight through no baffle alloy can on mine and it went awsome (as CK (previous owner) or mini_me (person who bought it from me)
3) and bullshit i got my zxr up to $1.93 so there goes that theory
4)leaking forks... take it to a mechanic you'll need new seals and don't think about trying to replace usd ones .. even the mechanicsc hate it. If you don't then your handelling will be affected greatly and you really don't want the front end bouncing around... or not as the case may be when tipping in.

[loosebruce]

as for the exaust, Noise I need :) so I'm not too worried about the low end



Just take the muffler off, who gives a toss about power on a 250 4 stroke, it'll scream for ya then, sounds like a scud missle taking off and you'll have all the peeps on the side walk covering there ears from the noise, wicked.
But really aint they loud enough standard, what year you have? My 89 is more than loud enough with a stock pipe, can't see any point in changing it. Damn thing will give the TL a run in the noise stakes.
Always keep an eye on ya cam chain, shit gets nasty when that fails (been there before, ohh thats a nice crack in the top of my rocker cover).
Get your forks sorted quick though, if it's still got oil left it can leak over your disc's and pads as well, makes stopping interesting (been there before) plus it turns the handling to utter shit. Once fixed you wont know the bike.

[John]

3) and bullshit i got my zxr up to $1.93 so there goes that theory


Wow your cool, I've had mine to 211.
Your my hero affman - I am going to buy a CBR600 just like yours :love:

Also Yes you will need backpreasure on these things ask tristan both the sound and middrange was depressing for him, just do What I did get a hammer and a socket T bone and wack it through the plates, make sure that the hole goes directly out the rear (.ie smash the hole the entire length to the outlet) makes it deeper and no major backpreasure loss.

[N4CR]

Ahh! I have just been experimenting with my exhaust this last week

-Debaffling
To open her up, drill out the rivets in the tip/end and slide all the crap out.
Re-rivet it back up and then away you go :D
Try taking the can off and seeing how it sounds - it is very similar so if you dont like it (im sure you will :msn-wink: ) you wont waste time doing it.
I have 2 cans, one stock and one empty... wof/no wof etc :D

Now everyone will actually notice your bike and not try make 'festivities' against you with their side panels etc

###

Results:
-Slow as hell (no pull) for the 2-10k range or there abouts, then when you hit about 14~k you will find yourself bouncing off the limiter before you even think about changing gears :lol:

Cure:
Get some chicken wire (this will NOT change sound levels) and then put a steel wool scouring pad into the exhaust around the end/tip , mush it into the chicken wire. If you dont mush it into the chicken wire it will come out if you hit the limiter.. as I found out today. ;)
The steel wool will shut it up a little so your ears are not sore/police attracting and also give you perfect midrange because of the slight increase in backpressure (wow it pulls again!). I found a silent spot around 6.5k for cruising but anything higher or lower is way too loud. The steel wool seems to absorb some sound energy while letting gas through - another thing to watch for is your valves.. don't debaffle it if you haven't had them checked for a while (I dunno what im talking about, hopefully someone else can explain.)

AND I just got ticking last week and have just done 21,000kms too, steel wool stopped it... valves I'm guessing. Service time methinks.

Found one of my old posts where I have drawn up the baffle system, just incase you want to puncture it and not remove it all.
http://www.kiwibiker.co.nz/forums/showthread.php?t=10850&highlight=zxr+baffle

[John]

don't debaffle it if you haven't had them checked for a while (I dunno what im talking about, hopefully someone else can explain.)

AND I just got ticking last week and have just done 21,000kms too, steel wool stopped it... valves I'm guessing. Service time methinks.


The main reason this will be happening to you tristan is the fact that you are leaning your fuel/air mixture, due to less pressure on the exhaust stroke, if your cool/(dumb) enough to a run zero backpressure type exhaust on a bike that you want to use as a commuter or anything then run the mixture richer, adjust your jets - try save your engine for a bit longer, oh and if your valves are dieing then they will probably be burnt/burning - what does this involve to fix, well apart from a shit load of money - you can get the valves grinded (we cant do ours I was looking at them and they are diamond coated I think that’s the term? most modern valves cant be ground I hear) or replacing them - wow that’s got to hurt. <o:p></o:p>

I am not going to go into dynamics of backpressure here as it will fall upon deaf ears, as a lot of my insightful posts do.

What I'm trying to say is - don’t bloody debaffle them, Everyone has different opinions on backpressure and damages just think about implications above pleasure - tristan instead of funking around with the exhaust why don’t you learn more about your engine - It will pay off - and you could buy a real bike once you've saved thousands doing your own servicing, I've learnt pretty much everything thanks to this bike and the spare engine, I was fairly competent before hand but now I feel old and wise<u1:shapetype id="_x0000_t75" coordsize="21600,21600" u2:spt="75" u2:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <u1:stroke joinstyle="miter"><u1:formulas><u1:f eqn="if lineDrawn pixelLineWidth 0"><u1:f eqn="sum @0 1 0"><u1:f eqn="sum 0 0 @1"><u1:f eqn="prod @2 1 2"><u1:f eqn="prod @3 21600 pixelWidth"><u1:f eqn="prod @3 21600 pixelHeight"><u1:f eqn="sum @0 0 1"><u1:f eqn="prod @6 1 2"><u1:f eqn="prod @7 21600 pixelWidth"><u1:f eqn="sum @8 21600 0"><u1:f eqn="prod @7 21600 pixelHeight"><u1:f eqn="sum @10 21600 0"></u1:f><u1:path u2:extrusionok="f" gradientshapeok="t" u2:connecttype="rect"><u2:lock u1:ext="edit" aspectratio="t"></u2:lock><u1:shape id="_x0000_i1025" type="#_x0000_t75" alt="" style="width: 15pt; height: 15pt;"><u1:imagedata src="file:///C:%5CDOCUME%7E1%5CJOHNMI%7E1%5CLOCALS%7E1%5CTemp%5 Cmsohtml1%5C01%5Cclip_image001.gif" u2:href="http://www.kiwibiker.co.nz/forums/images/smilies/yes.gif"></u1:imagedata>(heh). <o:p></o:p></u1:shape></u1:path></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:f></u1:formulas></u1:stroke></u1:shapetype>

So to evaluate if you’re going to debaffle your bike, either go buy a primea tack on a "free flow" exhaust and straight through independent headers, or run your bike richer to try save it some of its life - remember these things are freaken tiny - and very sensitive.<o:p></o:p>

Another thing all this ticking that everyone is experiencing maybe it would be important to get that checked, because worse thing could be rods or bearings starting to die due to abuse, have a nice day.

- Bitter Me :yes:

[HDTboy]

CBR 250s don't have cam chains :) just thought I'd give my 2c.
When i debaffled my bike it just got noisier, no performance difference noticed