needles_929

don't know?? I got it finished last night and we are still waiting on the new cage and clutch. I took the guts out of the pair valve because I didn't know if it actually was opening and too cheap to buy a plastic t

old man roger

let me first start buy saying i have not done an f4i but in the picture there is a crankcase vent ,it is on the left side of the valve cover and has the clear hose going to it

and the the two rubber hoses on top of the valve cover that are connected to the t are vented to the exhaust through reed valves so when the bike is running the reed valves will only open in one direction so it only lets the exhaust create a vaccum in the crank case not pressure

Trachito

okay, so i've gotten a bit confused now. the reed valves are located where, at the bottom of the two hoses? is Tanus' description of the other valve's function accurate? it made sense to me.

bottom line, it's okay to make this mod either by gutting the valve or replacing it with a T, no?

*Tanus*

I dont think it is like that, but Im going to pull the cover on my spare motor to see.

old man roger

wheeliest said the same thing to me about the 636.....lol

he took it all apart and then blew through the ports in the head only to see it went straight to the exhaust ports as described

old man roger

im not sure about using the stock t on an f4i because i have never done one but on the 636 there is a vaccum line that opens and closes that t so i just disconnected the vaccum line from the t but if you replace it with a regular t you should be fine

Trachito

Okay, got it: Just get a regular t so the lines remain open.

needles_929

the f4i doesn't have a vaccum line but opens from electronics. I guess it supposed to open when the bike is turned on and closed when shut off. I removed the guts because I figure if the valve had a problem and did not open correctly then maybe the bike would not run the same or maybe even mess somthing up. the valve with no guts is just the same as an open T. I did hear from some guy that it is better for the ecu to leave the valve plugged in???

old man roger

i haven't done an f4i so i don't know about how that t works but the way you describe it maybe leaving it plugged in but just take hoses off and replace it with a new t

that way the computer would think it's still hooked up ?

BigBalla

Google "Dan Kyle Racing"

they make block off plates for various bikes.

THORPE

I didn't take time to read this whole thread but i started the 636 thread originally.

Just here to tell you it works don't worry I did this mod to my F4i too and it helps the idle feel stronger, no oil in the airbox and all the good benifits just like the 636. I think it's safe to say it will work and help on any bike with a clean air valve. r6, gixxer, 636, f4i all have them. I'm sure alot of other bikes do too but I havent had experience with anything else.

The one thing for sure is it was easier to do on the f4i. I only had to buy a T fitting and that was it!
The rest was just swapping the stock hoses around to make the crank vent t into the kleen air hoses on top of the valve cover, everything is right there close.

I'm about to try it on my hopped up pit bike to see if it helps to vent the crankcase to the exhaust like that. Mainly for low end power increase... every little bit helps

THORPE

That's what i did just left it plugged in and bypassed with a T.

WOrks great and doesn't throw any FI codes.
You don't even have to unbolt it just leave it there. zip tie the new one to it to hold it in place for good measure,

One more thing i haven;t read the whole thread so this may have been mentioned already...but make sure you block off the airbox hole after you remove the hose. I swapped ends with my hose because the curves lined up better when hooking it up to the new T.

GAMstunts

rode mine last night for the first time with the mod done, love it,runs better thaN EVER. I had a hesitation in my idle since I bought it now it runs smooth as silk. If you have an f4i just spend the $2 on a plastic t and do it, takes 15 min. and my bike just pulls me around.

Beto

I guess I'll be doing it to mine soon

DSC

i have done it both ways with t and gutting the pair valve. there is no difference with it pluged up or not pluged up so it doesn't really matter. if you don't agree just put you hand infront of the valve when running and feel it suckin your hand to the valve

p.s. omr as i was reading the threads all i could think was here we go again

old man roger

yep ....lol

*Tanus*

I checked, the f4i isnt like that,the only way for crankcase pressure to get to the exhaust is through worn valve guides.

old man roger

sorry but you are mistaken



and thats what wheeliest said at first too....lol

*Tanus*

I looked in the exhaust port,nothing but 2 valves,I looked with a bright *** flashlight too

old man roger

there are ports in the bowl area of the exhaust port that you cant see



if you have a spare then just take off the parts that the two hoses are connected too in the picture that was posted and remove the reed valve and you will see a hole inside of each side ,blow through the whole with an air hose and you will be able to hear the air coming out of the exhaust port