how to air box mod f4i
01-04-2008, 02:06 PM
#142
Registered User
Join Date: Apr 2007
Location: Billings Heights, MT, USA
Posts: 563
Re: how to air box mod f4i
Did this last night.....clean air mod and removal of the tip over sensor as I still love that wheelie sensation!!!
The clean air mod will give you better low end for two reasons ... this is why racers love it.....
1- you don't get any of the hot oily air from the crank case in your airbox---Take an automotive spray gun, The air blowing by the small jet pulls paint from the canister and doesn't blow pressure into the can...... Same thing here, the exhaust blows by and pulls the hot air / oil from the crancase with it...
2- by hooking the crankcase vent tube up to the clean air valve it creates a vaccum in the crank case and that is good for a few extra horse power and a couple foot pounds of torque...OMR (aka the man) said..."it makes the bike better all around and alot of people agree ,i have even seen dyno test that show increased torque and horse power"
The stunters love it because it prevents a hydrolock situation from the bike being on its side and oil being dumped into the airbox from the breather tube....it has been argued over and over and proven, this is a great mod with no bad side effects whatsoever....
This is what it looks like stock....the directions are a bit confusing, throw 3 away, and hook 1 2 and 4 to the new t....
The pair valve removed....
1/2" Tee...it was very tight, had to vaseline the hoses to get them on, but better than too loose....
Here is a pic of the t with the hoses.....
How I sealed the airbox off, I have seen many methods, but looking around the garage I realized that some old tire valve cover caps fit perfectly and are hard enough to hold, through them in with a little epoxy and they were solid and fit perfect, looks factory...
Also here is the tipover sensor mod as well.... just cut that damn thing out and never worry about it again....
With windscreen off...
Remove the 2 screws holding the box in and disconnect the box...
Here it is removed and unclipped....
Cut off the connector and make sure there is enough room to reconnect if you want to reinstall in the feature, tie red and green together and cap white off....and clip back in....
The clean air mod will give you better low end for two reasons ... this is why racers love it.....
1- you don't get any of the hot oily air from the crank case in your airbox---Take an automotive spray gun, The air blowing by the small jet pulls paint from the canister and doesn't blow pressure into the can...... Same thing here, the exhaust blows by and pulls the hot air / oil from the crancase with it...
2- by hooking the crankcase vent tube up to the clean air valve it creates a vaccum in the crank case and that is good for a few extra horse power and a couple foot pounds of torque...OMR (aka the man) said..."it makes the bike better all around and alot of people agree ,i have even seen dyno test that show increased torque and horse power"
The stunters love it because it prevents a hydrolock situation from the bike being on its side and oil being dumped into the airbox from the breather tube....it has been argued over and over and proven, this is a great mod with no bad side effects whatsoever....
This is what it looks like stock....the directions are a bit confusing, throw 3 away, and hook 1 2 and 4 to the new t....
The pair valve removed....
1/2" Tee...it was very tight, had to vaseline the hoses to get them on, but better than too loose....
Here is a pic of the t with the hoses.....
How I sealed the airbox off, I have seen many methods, but looking around the garage I realized that some old tire valve cover caps fit perfectly and are hard enough to hold, through them in with a little epoxy and they were solid and fit perfect, looks factory...
Also here is the tipover sensor mod as well.... just cut that damn thing out and never worry about it again....
With windscreen off...
Remove the 2 screws holding the box in and disconnect the box...
Here it is removed and unclipped....
Cut off the connector and make sure there is enough room to reconnect if you want to reinstall in the feature, tie red and green together and cap white off....and clip back in....
01-05-2008, 05:39 AM
#143
Registered User
Join Date: Aug 2007
Location: anaheim
Posts: 2,443
Re: how to air box mod f4i
you guys talk about taping the airbox.. i have tried this an noticed a diffrence but i thought about it wouldnt the stock idle do similar thing by adjusting fuel mixture... cause isnt it basically the ssame thing?
01-05-2008, 06:15 AM
#144
Registered User
Join Date: Jan 2007
Location: LA, CA, USA
Posts: 2,593
Re: how to air box mod f4i
thats why you have to re-adjust the idle (using the stock cable) after doing this mod.
01-05-2008, 11:49 AM
#146
Registered User
Join Date: Dec 2005
Posts: 1,648
Re: how to air box mod f4i
so
will she suck harder if u take the reed valves out of the cam cover....?
and thanks everyone for the tips
cos i hadn't tried the adjust of the original idle
but i rember when i first did the 2nd cable mod there was advice suggesting the base idle setting should be left alone.......?
it just an air bypass i think....
haven't ridden it like a month now in between engine swaps and spraying
will she suck harder if u take the reed valves out of the cam cover....?
and thanks everyone for the tips
cos i hadn't tried the adjust of the original idle
but i rember when i first did the 2nd cable mod there was advice suggesting the base idle setting should be left alone.......?
it just an air bypass i think....
haven't ridden it like a month now in between engine swaps and spraying
Last edited by ALSTAR; 01-05-2008 at 12:04 PM.
01-05-2008, 12:09 PM
#147
also known as OMR
Join Date: Jul 2006
Location: OMR INDUSTRIES in west palm beach florida
Posts: 79,288
Re: how to air box mod f4i
so
will she suck harder if u take the reed valves out of the cam cover....?
and thanks everyone for the tips
cos i hadn't tried the adjust of the original idle
but i rember when i first did the 2nd cable mod there was advice suggesting the base idle setting should be left alone.......?
it just an air bypass i think....
haven't ridden it like a month now in between engine swaps and spraying
will she suck harder if u take the reed valves out of the cam cover....?
and thanks everyone for the tips
cos i hadn't tried the adjust of the original idle
but i rember when i first did the 2nd cable mod there was advice suggesting the base idle setting should be left alone.......?
it just an air bypass i think....
haven't ridden it like a month now in between engine swaps and spraying
01-05-2008, 12:26 PM
#151
Registered User
Join Date: Dec 2005
Posts: 1,648
Re: how to air box mod f4i
01-10-2008, 10:22 PM
#155
Registered User
Join Date: Nov 2002
Location: Vancouver
Age: 44
Posts: 1,553
Re: how to air box mod f4i
I did this a while ago just gutting the valve, but re-did it tonight using a proper T-fitting so thought I'd add to this thread. I used a 1/2 inch inner diameter fitting that I got from Home Depot for 67 cents. It fit percectly, nice and tight. I just used the 3 normal hoses and threw out the big one.
Another idea for vacum caps = use a few layers of electrical tape and cut some segments from the big hose you end up throwing out and shove em on (see 3rd pic).
Another idea for vacum caps = use a few layers of electrical tape and cut some segments from the big hose you end up throwing out and shove em on (see 3rd pic).
01-11-2008, 03:15 AM
#156
Registered User
Join Date: Aug 2007
Location: anaheim
Posts: 2,443
Re: how to air box mod f4i
i jus heard today that it causes problems when you do it this way, i have mine like that an my bike is running like garbage.
i was told to completely cap off the two front nipples an the crancase vent jus run a huse towards the ground with a small filter an your good.
what do you guys think?
i was told to completely cap off the two front nipples an the crancase vent jus run a huse towards the ground with a small filter an your good.
what do you guys think?
01-11-2008, 12:43 PM
#158
Registered User
Join Date: Oct 2004
Location: Anywhere wheelies happen
Age: 37
Posts: 5,869
Re: how to air box mod f4i
i jus heard today that it causes problems when you do it this way, i have mine like that an my bike is running like garbage.
i was told to completely cap off the two front nipples an the crancase vent jus run a huse towards the ground with a small filter an your good.
what do you guys think?
i was told to completely cap off the two front nipples an the crancase vent jus run a huse towards the ground with a small filter an your good.
what do you guys think?
dozens of people have done this mod..
01-11-2008, 01:23 PM
#159
Registered User
Join Date: Nov 2002
Location: Vancouver
Age: 44
Posts: 1,553
Re: how to air box mod f4i
who did you hear that from?
I had it done for a while already with just the gutted valve and it was running great. It should run the same with the T-fitting. If it's running wierd maby it's cuz the valve unit isn't plugged in
Sunday should be dry here so if I go ride i'll find out. If it runs like crap i'll plug in the valve and see what that does
I had it done for a while already with just the gutted valve and it was running great. It should run the same with the T-fitting. If it's running wierd maby it's cuz the valve unit isn't plugged in
Sunday should be dry here so if I go ride i'll find out. If it runs like crap i'll plug in the valve and see what that does
