Anyone run a 250 with airbox removed

GM1216 · May 28th, 2019, 03:05 PM

Now i hauled my $100 Ninja back to Illinois from Kansas and I am deciding what to do with her.

Only way i would build her back to stock is to sell, so i'm probably going to raid my pile of spares and build a fun little commuter for grins on the way to my work.

First I need a acquire a set of carbs, currently has airbox but this will be removed as Frame is definitely going to be modified and i want to hide all the electrical gubbins out of sight and if it has any bodywork it will be a minimal hand built carbon tail unit and undertail exhaust.

Anyway I digress, My question is has anyone junked the airbox and ran pod filters? how did it run? Did it need rejetting or can i tune ECU to smooth out any fueling issues?

Thanks in advance

DannoXYZ · May 28th, 2019, 03:17 PM

Hi, welcome to Ninjette!

A lot of people (me included) have removed airbox or acquired bike without airbox. Pretty much all of them re-install airbox. Bike runs like crap with pod filters and no amount of jetting changes fixes issue.

Some problems are external to carb, such as stumbling in cross-winds. No amount of tuning can anticipate or alleviate that. I suppose you can install pitot tube head of fairings and connect that to float-bowls and have it adjust fuel based upon wind-direction.

GM1216 · May 28th, 2019, 06:51 PM

Quote:

Originally Posted by DannoXYZ

Hi, welcome to Ninjette!

A lot of people (me included) have removed airbox or acquired bike without airbox. Pretty much all of them re-install airbox. Bike runs like crap with pod filters and no amount of jetting changes fixes issue.

Some problems are external to carb, such as stumbling in cross-winds. No amount of tuning can anticipate or alleviate that. I suppose you can install pitot tube head of fairings and connect that to float-bowls and have it adjust fuel based upon wind-direction.

Thanks for the response. interesting that external variables would play such a big part, I've always ran pods on my old oil cooled suzuki's but also have always paid to have them set up on a dyno. guess with that much power and fuel i never notice any issues with external forces before

I don't want to start spending big bucks like my other bikes but i am thinking maybe i can get one of my english homies to send me a set of EFI throttle bodies, harness and ECU if the price is right and correct any issues with a dyno jet and auto tune.

I tricked my Z1000 into running ZX10 Tb's with a 636 dynojet so i guess it's viable

I'll have to decide how extreme I wanna go with this build. it started as a bit of nostalgia because i haven't had a bike this tiny for 25 years. lookslike a bmx with a motor

GM1216 · May 28th, 2019, 06:51 PM

Quote:

Originally Posted by DannoXYZ

Hi, welcome to Ninjette!

A lot of people (me included) have removed airbox or acquired bike without airbox. Pretty much all of them re-install airbox. Bike runs like crap with pod filters and no amount of jetting changes fixes issue.

Some problems are external to carb, such as stumbling in cross-winds. No amount of tuning can anticipate or alleviate that. I suppose you can install pitot tube head of fairings and connect that to float-bowls and have it adjust fuel based upon wind-direction.

Thanks for the response. interesting that external variables would play such a big part, I've always ran pods on my old oil cooled suzuki's but also have always paid to have them set up on a dyno. guess with that much power and fuel i never notice any issues with external forces before

I don't want to start spending big bucks like my other bikes but i am thinking maybe i can get one of my english homies to send me a set of EFI throttle bodies, harness and ECU if the price is right and correct any issues with a dyno jet and auto tune.

I tricked my Z1000 into running ZX10 Tb's with a 636 dynojet so i guess it's viable

I'll have to decide how extreme I wanna go with this build. it started as a bit of nostalgia because i haven't had a bike this tiny for 25 years. lookslike a bmx with a motor

DannoXYZ · May 28th, 2019, 08:35 PM

Heh, heh, yeah pretty simple with extras removed.

Simple enough to get complete EFI setup from 300 and use PC-V for tuning. Someone has ability to reprogram 300 ECU, but they charge too much to make it worthwhile.

Tooch · May 28th, 2019, 11:42 PM

I'm currently running pod filters on my wife's '08 with a stage 2 Dynojet kit with no issues whatsoever. But it seems like this may be the exception, not the rule

gantt · May 29th, 2019, 07:02 AM

i ran a pod style, and chased issues for a while. finally just bought a used airbox that was not modified, removed the snorkel and dropped a K&N filter in the airbox and called it a day. for you, wanting to remove the airbox for reasons other than to try and get more power, maybe it would be worth the hassle to make it right. i dont know, i had odd surges and stumbles with a pod filter.
whoever mentioned the 300 fuel injection setup has a good idea. ditch the carbs and be done with it. i'd imagine the throttle bodies would be less susceptible to issues due to a pod filter.

2fiddy-trackpair · May 29th, 2019, 09:10 AM

I just completed my build, air box deleted, with the K&N RU-1822 filters and Factory Pro jet kit and she runs great.

Triple Jim · May 29th, 2019, 09:42 AM

Quote:

Originally Posted by 2fiddy-trackpair

I just completed my build, air box deleted, with the K&N RU-1822 filters and Factory Pro jet kit and she runs great.

Have you checked the fuel economy? I'm just curious because sometimes it's easy to get an engine running well, but at the expense of fuel usage.

GM1216 · May 29th, 2019, 01:14 PM

Quote:

Originally Posted by Triple Jim

Have you checked the fuel economy? I'm just curious because sometimes it's easy to get an engine running well, but at the expense of fuel usage.

Not to bothered by fuel economy to be honest, I have 3 other tuned liter motorcycles so a 250 burning a little more fuel is negligible lol

Thanks every one for your replies, i will mull over my option while i strip her down and service all the parts.

Meanwhile gotta finish my Z1000 so i'm not rushing with this build, I'm also toying with the idea of putting the motor into a KZ frame with modern running gear.

I mentioned elsewhere i believe that i don't follow a plan when i build i just let the bikes evolve to what they eventually become and without trying to sound like i have an over inflated ego I do build high quality bikes

May 28th, 2019, 03:05 PM	#1
GM1216 ninjette.org newbie Name: Dave Location: Edge of Sanity Join Date: May 2019 Motorcycle(s): Suzuki Gsxr 7/1216, kawasaki z1000, Triumph Speed Triple, 250 ninja Posts: 6	Anyone run a 250 with airbox removed Now i hauled my $100 Ninja back to Illinois from Kansas and I am deciding what to do with her. Only way i would build her back to stock is to sell, so i'm probably going to raid my pile of spares and build a fun little commuter for grins on the way to my work. First I need a acquire a set of carbs, currently has airbox but this will be removed as Frame is definitely going to be modified and i want to hide all the electrical gubbins out of sight and if it has any bodywork it will be a minimal hand built carbon tail unit and undertail exhaust. Anyway I digress, My question is has anyone junked the airbox and ran pod filters? how did it run? Did it need rejetting or can i tune ECU to smooth out any fueling issues? Thanks in advance

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May 28th, 2019, 03:17 PM	#2
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Hi, welcome to Ninjette! A lot of people (me included) have removed airbox or acquired bike without airbox. Pretty much all of them re-install airbox. Bike runs like crap with pod filters and no amount of jetting changes fixes issue. Some problems are external to carb, such as stumbling in cross-winds. No amount of tuning can anticipate or alleviate that. I suppose you can install pitot tube head of fairings and connect that to float-bowls and have it adjust fuel based upon wind-direction.

May 28th, 2019, 08:35 PM	#5
DannoXYZ ninjette.org certified postwhore Name: AKA JacRyann Location: Mesa, AZ Join Date: Dec 2011 Motorcycle(s): CB125T CBR250R-MC19 CBR250RR-MC22 NSR350R-MC21 VF500F CBR600RR SFV650 VFR750F R1M ST1300PA Valkyrie-F6C Posts: A lot. MOTY - 2018, MOTM - Nov '17	Heh, heh, yeah pretty simple with extras removed. Simple enough to get complete EFI setup from 300 and use PC-V for tuning. Someone has ability to reprogram 300 ECU, but they charge too much to make it worthwhile.

May 28th, 2019, 11:42 PM	#6
Tooch ninjette.org member Name: Anthony Location: Pittsburgh Join Date: Mar 2019 Motorcycle(s): 2008 Ninja 250, 2015 zx10r, 2010 Ducati 848 Posts: 75	I'm currently running pod filters on my wife's '08 with a stage 2 Dynojet kit with no issues whatsoever. But it seems like this may be the exception, not the rule

May 29th, 2019, 07:02 AM	#7
gantt ninjette.org sage Name: michael Location: Central Georgia Join Date: May 2013 Motorcycle(s): 2019 Ninja 400, Sold 2012 Ninja 650, Sold 2009 Ninja 250r, Sold 2007 DRZ400s Posts: 628	i ran a pod style, and chased issues for a while. finally just bought a used airbox that was not modified, removed the snorkel and dropped a K&N filter in the airbox and called it a day. for you, wanting to remove the airbox for reasons other than to try and get more power, maybe it would be worth the hassle to make it right. i dont know, i had odd surges and stumbles with a pod filter. whoever mentioned the 300 fuel injection setup has a good idea. ditch the carbs and be done with it. i'd imagine the throttle bodies would be less susceptible to issues due to a pod filter.

May 29th, 2019, 09:10 AM	#8
2fiddy-trackpair ninjette.org member Name: Fred Location: Oklahoma Join Date: Feb 2015 Motorcycle(s): 2012 250r Posts: 41	I just completed my build, air box deleted, with the K&N RU-1822 filters and Factory Pro jet kit and she runs great.