F4i issues...

[AntwanRTTG]

I am about to sell this damn thing if I can't get it figured out.
I just completely rebuilt an F4i and I can't figure out what's wrong with it. The bike runs great, I can ride down the street with quick throttle response and without hesitation. However, when I go to clutch it up from a dead stop...when I go to get back into the throttle, the bike boggs out and falls on its face. I have tried almost everything that I can think of. Anyone ever had this?

Here is what I have checked:
-ohmed the injectors
-new plugs
-thought it might be a gas cap issue because I have a vortex, so I tried a stock cap
-full of gas, half full of gas .... doesn't matter, same outcome
-checked all vacuum lines and routing
-I did the idle screw mod at first, figured that was what caused it so I put it back to stock
-tip over sensor has been removed and bypassed
-airbox has been modded to remove the PAIR valve
-I am going to try synching the TB's tonight and see what that does

[thomas]

i remember Big Kris old f4i lugged like that and he went through it once and said it was great afterwards.. wish I could tell ya what he did

[AntwanRTTG]

How long ago? Was it a discussion on one of the boards?

[thomas]

it was like a year ago.. nah he doesnt post too much..I know they took out the entire throttle bodies and cleaned them well.. also put the idle screw back up in the fron, but make sure you leave the stock one in as well... the stock one controls air flow, so that one has to be set at the regular spot

[AntwanRTTG]

Yeah, I knew all of that abuot the idle. Thanks anyway. I am going to synch the TB and try my buddy's tank(different fuel pump), just to rule that out.

[T-Dubby]

I need to sync mine.. My bike doesn't pull very hard.. I rode #2s bike and that thing pulls awesome.

[Bobby digital]

my boys bike was doing the same thing and he switched fuel pumps and that didnt fix it, but i dont think his does it all the time

[*Tanus*]

Originally Posted by T-Dubby

I need to sync mine.. .

me too,whos got that vacuum shit you need to sync em?

[AntwanRTTG]

Well, the fix was something that is still not settling with me. I guess I just needed taller gearing. I was running stock front +8 rear. I put a buddy's 74 tooth rear on it and it worked perfect. This is weird because I know that people are stunting F4i's with +8 gearing or less. Or are they?

Either way, I just put a new set of sprockets on and everything is great. I went -1/+16 and it pulls like a champ and doesn't bogg out like it was. I am not totally convinced that something else wasn't wrong.

Oh well...

[CORPSE]

mine does that and my friends does it too, its not consistent though, it comes and goes... were completely lost on the situation