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intake outlet diameter? for DIY intake mod

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61K views 61 replies 33 participants last post by  carmikey  
#1 ·
Anybody know the diameter of the intake port on the Z125? I have a few silicon hoses running from 1inch to 3inch around the house was thinking about just clamping one of those on with a K&N intake filter or so.
 
#3 ·
I AGREE, THESE INTAKES ARE WAY OVER PRICED. A CHEAP SILICONE TUBE AND A BREATHER FILTER THAT WOULD SIT ON TOP OF A VALVE COVER:laugh:, ILL DO MY OWN AND BETTER! STEADY GARAGE SELLS AN OVER SIZED THROTTLE BODY ASSEMBLY. IT SAYS ITS 26MM, I FIGURED ITS ABOUT 1 INCH
 
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#4 ·
your about right just went to the site and looked up that throttle body and it states "OEM stock size is 24mm, Chimera is 26mm! ALL OEM Sensors are intact". I will double check just incase.

Looks like the Dayco C71289 radiator hose will fit it has a inside diameter of 1.34" and already has a bend so all you need to do is cut it accordingly. Same hoses as a lot of the Grom guys are using to Mod their airbox.
 
#11 ·
I already cut my box with a 1inch hole saw. I dont have access to a bike dyno however the noise has increased alot. According to all these vendors with no dyno sheets. More noise means more power lol
 
#6 ·
To add on the Dayco hose has a 40mm outside diameter so check out the K&N RC-2314. It is nearly identical to the one that goes on the chimera intake with the exception of its Flange inside diameter of 40mm vs the 50mm that the chimera uses. This will fit the dayco if anyone is having a hard time finding a hose..
 
#7 ·
No need to replace the hose just break the glue around the original hose that attaches to the air box. Pull the hose out of the air box and you will notice it has a lip on the end which is perfect then go buy a filter with I think a 2 inch diameter make sure the lip slides in the filter and whalaa.
 

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#9 ·
Thanks for that!! I just order the air filter! I run that exact filter on my dirt bike lol.. Once it comes in i'll be dismantling the air box!

The air filter is By "Uni", just ebay "50mm uni air filter" and a schwack of them will come up and for around $20. Great air filter and i ran mine on my dirt bike for a year now, you just need to pre oil them before installing.
 
#16 ·
what I've been wanting to do is weld up a bung I have for a o2 sensor so I can use my wideband gauge and get a reading before any mods

but after looking how skinny the exhaust pipe is I'm not sure if my bung will fit nicely, as its pretty large
plus its a brand new bike, and really want to spend time riding it rather then tearing it all apart right now

plus gives me a chance to get used to the power and speeds it does on hills and flat ground

so when I do modify it will help me see if there are any negative changes because of the mods



because that would make it much easier to see when changing the air intake how much the fuel injector can compensate for the changes by seeing what the wideband shows
or when adding an exhaust


then at least when you start to do changes if you need to raise the fuel then its time for a fuel controller and will also be able to get it tuned perfectly

I have used a tail pipe sniffer on other bikes but with the z exhaust its already super low and will be hard for me to secure the sniffer

why I bought a bag of bungs and plus and would be a lot easier to check tuning just by screwing in and out a sensor rather then rigging up something hanging off the exhaust





my guess at least on my Ca model it will be set pretty lean to start with for all the emissions stuff we need here

and I would hate to lean it out even more doing any intake or exhaust upgrades unless I can verify myself whats going on
 
#17 ·
I was told by my dealer that all of our bikes are CA models.

As far as the Chimera intake I ordered, was a waste of money the quality was shoddy and I don't think they even dyno tuned for runner length it would bog at low rpm, I honestly didn't see that much of an improvement if any with it. Save your money on the intake although I was impressed with the SF waterproof filter.
 
#18 ·
I looked closer at adding a bung to my stock header
and it won't work
even if I could get the bung on my o2 I would be using would sit in too deep and hit the backside of the pipe and probably block too much flow


I was thinking maybe on the muffler right under the exhaust piping but I will need to find that video of this guy cutting one apart I'm thinking its baffled or its a tube where I would weld and probably be blocked too


sucks because I do want to get before and after readings with my wideband

all I have left is to rig up a tail pipe sniffer and do that so at least I do have that option if I can't figure out anything else
 
#20 · (Edited)
hmm that looks interesting

but I still need to leave the stock o2 sensor in the pipe so the bike can run off of that
I wonder if using that adapter I can find that smaller bung, or a nut and weld that to the exhaust

then use a plug, or bolt later to cap it off

I don't plan on using the wideband all the time only when doing changes and want to see what changes happen



also just found this a riser
Image


but the bungs I have still are pretty large compared to the pipe so still trying to figure out what to use

the adapter you posted is better because it will require a smaller bung to be added
 
#21 · (Edited)
maybe this will work as a 12mm bung
for that adapter you posted


Oil Pan Drain Plug Weld in Kit Steel 12mm Steel Bung Steel Plug Washer | eBay


plus it has a plug too







I ordered that adapter and this plug shown above


so that should get me what I want for this bikes exhaust an easy way to test when doing any changes

this way I can look into stock air box modding and see what happens with the fueling
 
#23 ·
#39 ·
Double post don't kill me. I don't want to pull the trigger too quickly (and bike isnt within my reach to check) I like the look of the UNI filter a lot, as well as it keeping out dirt more efficiently.
However I see that the the uni's posted were 50MM where as the K&N both have a smaller I.D. of 35MM

I'm lost af help lol.