Yamaha32088

I know there is a seperate section for troubleshooting but it seems more people are in this area. I have a 2003 F4I i purchased used it always ran decent but seemed to lack low end torque. I recently had to tear it all apart to fix some stripped out motor mounts (which i didnt cause). So after all the work of pretty much dropping the motor to put in helicoils I noticed a few odd things. There are 2 hoses that come off the throttle bodies in my service manual it looks to be #1 and #4 vacuum hoses. The #4 hose had a screw stuck in it and #1 had nothing. Im assuming these are the hoses that use to run up to the airbox before the Kleen air mod was done. Should both of them be plugged up or should they be left open. Also another thing i noticed was that the MAP sensor hose was connected to the sensor but no where else. I have looked in the service manual and different microphighes and cannot determine where the other end of the hose is supposed to connect. Any help is greatly appreciated.

ATOWN1101

The 2 little hoses about a 1/4in in size go into the back of the air box. and they have nothing to do with the clean air mod if those are the hoses you are talking about. so plug them back in as for the map sensor i have no idea were it even is on the bike so cant help you there

roadsurfr7

if the small hoses arent attached to the air box the bike will have a pretty big power loss.

solukcom

The map sensor is supposed to be screwed into the left under-side of the airbox with a coarse thread screw, it has a plug and hose that plugs into the bottom. The 2 hoses that are plugged with screws are supposed to attach to the "posts" on the back under-side of the airbox but the screws are fine as long as they're plugged. That just skips one more step when taking off and putting on your airbox. Check the intake boots, make sure they are fully seated and make sure the clamps are tight. Make sure the coil packs are seated on top of the spark plugs too, a lot of people have problems seating them on F4i's for some reason.

I just re-read your post. The other end of the map sensor plugs into that mass of vacuum lines, you should be able to see where it goes if you pull the tank off and check those hoses. I can take a picture of mine and send it to ya but it will be on Friday when I get home.

Yamaha32088

Thanks everyone for your help I think i should have it all figured out now now just 4 more months of winter till i can ride the damn thing.

solukcom

Screw waiting, your not a waiter! Kick the tires and light the fires!!!

bdhstunt

I'm trying to sync my throttle bodies now and all those vacum lines every were sux

Ethiopian

im sorry.

punishmentcycle

theres a 5 way vac line splitter under the throttle bodies..thats where the map taps in

sixxxer-fuddy

so u can block off thos 2 ,1/4 inch lines correct??? i broke a post off when takein off the airbox