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how big is too big for exhaust

3917 Views 41 Replies 8 Participants Last post by  drgnprelude
well i saw that one guy put a monkey bike exhaust on his x 18 and thats exactly the look i was going for my x 19. i found this pipe tho.. http://www.ebay.com/itm/Racing-Big-...es&hash=item231f985f14&vxp=mtr#ht_4536wt_1037 says its 48mm.. and i just checked that out on a ruler and it seems like it may be a little too big but i wasnt sure. btw i have a 140cc lifan.
yea i really dont wanna mess with all the little exhaust tips and pipes i bought before....
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I'm sure it will fit. But with such a big size, you aren't going to have much back pressure. And it's going to sound deeeep and louuud lol
Well your motor may run hotter because a bigger pipe does not flow or scavenge as much as a smaller pipe and believe it or not smaller pipes flow better at lower rpm better than bigger ones
Also you will gain in top end but will lose considerably in the low rpm range its best to use a smaller pipe from the motor and open up to a bigger pipe about a foot or so down to help scavenge and make good low and top end power
Plus that pipe does not look like it will fit the bike it looks like it will not work I can't tell by the pics tho but maybe you will need to cut and reweld to make that one work

Just my 2cents
thanks, yea i get what your saying. not so much about why it would run hotter but thats something id like to avoid. i guess ill stick with my orig plan but what about this one? http://www.ebay.com/itm/New-Style-R...es&hash=item257332d182&vxp=mtr#ht_3156wt_1037
it fit on someones x 18, idk what size motor he had tho.
It won't run that much hotter but it will some because scavenging pulls the exhaust stroke from the motor allowing it to run cooler and flow more
That first pipe see if you can find out the pipe diameter I didn't see it maybe it is or is not listed
The second one looks good someone else here did that pipe see how they like it
What I didn't like about that one tho is it looks from the other members post is it goes from a small pipe to a big one but then it looks like the muffler tip is actually small like about a 1 maybe 1-1/4 kinda weird
On my stock 110 I used the stock head pipe and once it made the bend went to 1/1/4 my pipe for my 150 is 1-1/4 to 1-1/2 then both types go into a y pipe then two mufflers its mostly just for looks plus I like the loud rumble when on it then the piping on deceleration lol
For $69 and $16 shipping at PBParts in Florida you can get an X12 hp side pipe. Very light, very noisey.


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Pipes are big but they are also long, back pressure should be ok due to the length. Guessing you may loose some bottom end but not much. If you need to reduce the size to gain better low end just replace the first 6-10 inches with a smaller diameter pipe.

Did some calcs for a pipe year or two ago (briansx19haulsass) top speed thread. You should be able to compare those to what your looking at.

yea i looked for that but couldnt find anything. hey does any one have anything good or bad to say about these? http://www.ebay.com/itm/RED-Engine-...9327&pid=100015&prg=1006&rk=1&#ht_4490wt_1037
and do they fit lifan motors? it looks like it would from the pics but not to sure.
I think that's the same one I got look around I got mine for $25 shipped
If you want to race most tracks make that manditory I got it going from my head breather and my PCB/breather hose and on the left rear upper seat tube just fits there
okay cool, i just though it was neat, head and crank breather and catch can all in one for a nice price cuz separate its over twice as much.
ya they are good, i made one out of pvc and some fittings and a small filter/breather, it goes to the rear case vent on the motor, that is where alot of oil will spray out and get all over your bike, so it helps keep it clean too
im not a fan of having more than one thing to a can cause it can cause a cross pulse or vacuum you dont want
a long time ago i had a carb suck the oil out of the case till it shut off, since then i dont mess with the carb, it only leaks when i wreck
yea i get what your saying about a vacuum, between the head and crank case? pry just unplug the head breather from the can and close it up. then id get the both vented and any oil spray out will go back into the engine. sound good?
kinda confused, the vents pulse in and out, if the case pulses out when the headbreather pulses in, will it start to flow the oil?
na get the kit but dont hook the head breather to the can and close that opening on the can. so only the hose from the crank case, hose to dip stick and the hose that lets air out will be on the can. and the head breather will just be a regular head breather. so no vacuuming, catch can that puts oil back in engine, vented crank case and head breather all for 40 bucks
woo i just found the exhaust iv been looking for. http://www.ooracing.com/store/index.php?act=viewProd&productId=116
and here it is on a monkey bike http://www.ooracing.com/thegovernor.htm
think it will fit?
oh well nvm.. there not the same pipe.. if you click on more images on the page that has the pipe for sale it shows what it looks like on a bike. not exactly what i was looking for but im thinking this one will deff fit.
woo i just found the exhaust iv been looking for. http://www.ooracing.com/store/index.php?act=viewProd&productId=116
and here it is on a monkey bike http://www.ooracing.com/thegovernor.htm
think it will fit?
There was a member on here that put those on his 4 stroke x7 a while back. I thought stuck out to much as far as the width. Made think of saddle bags on a sportbike. There's a short vid he posted on youtube. I think if done right they can look good.
Hey derrick, i will let ya know how the monkey bike exhaust performs once i get my farking clutch in....i knew i shouldnt have ordered one from the UK......been over a week.....and still no clutch....
okay thanks man. i couldnt buy that exhaust if i wanted too, they dont ship to america... :(
what???? i just got it off ebay and i live just south of chicago IL.....
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