ok so i have this 2002 f4i and when im in the lot riding, my bike is idled up like usual and then after a while into the session my bikes idle will start to jump up and down. it will go from around 3800 and drop to 3200, 3000 or so and then back up it will do it randomly too. it will be fine for like 30 to 45 seconds maybe then drop and sit there for like 5 seconds and go back up. riding slow wheelies riding idle this is really annoying. i think it only does this when it gets really warm like 210 or 220ish. because i rode home from the lot and my bike was at 180ish and i idled it up and it was steady like it should be. the other peoples f4i's that i ride with dont do this.

I am running the second idle cable that is screwed into the throttle body and yes i still have the stock idle down below. im going out to check the plugs now and see how they are. if you can think of anything let me know

 

mine was doin that recently and oddly enough it was because i was a little low on coolant.

 

you may need a throttle body sync, my bike i just sold ran like garbage and that was why. Now i can't figure out why my f4i i have now sucks, haha

 

coolant is full


and how would i sync the throttle bodies? would i have to take it in?

 

check the vacuum lines to the airbox.

 

just pulled the air box off and they were all on there hooked up correctly

 

I got the same problem, input on this would be much appreciated

 

good luck. I still have that problem and I changed the plugs, fuel pump, drained the gas from tank, synced the throttle bodies, replaced the map sensor and fuel regulator. I think my problem is dirty injectors/throttle assembly cause when I put in some injector cleaner it ran fine for a while. Also, when I set the the idle mod to 1k it runs fine

 

I just went through that problem. My bike would run fine for 20 min or so and then start jumping. I found out I had a small leak in the radiator and was running low on collant. I fixed the radiator with a little JB weld and filled the collant and it runs fine.

 

its not coolant i know that because my raidiator is full everytime i check it

and i did run some seafoam through it and it made no difference. checked the plugs yesterday and they looked fine, i dont know what it is

 

mine did that and the coil pack to one of the plugs was loose........over heating from low coolant and so on are all posibillities, but I would also run a lil Heat thru a tank mixed with ur gas to make sure you get any water out of your system. I've seen two bikes with NO water in the tanks, but the water was sitting in the fuel rails. The water's heavier than gas, sinks to the bottom, but is too thick/big to go thru ur fuel injectors. You can also pull ur tank and blow you fuel rails out with compressed water....done this on 2 636's so far and it got all the water out nicely.

good luck

 

coil packs are good and tight, and wouldnt sea foam do the same as that Heat stuff? i dunno i am gonna run a couple different things through the next tanks of gas, ill try that heat stuff and an actual injector cleaner, cuz i know seafoam is kind of an everything addative so maybe it doesnt work as well as one of specified additives

 

when he said check the vacuum lines he meant with a carb balancer, to check if you have the same vacuum in all 4 lines, i don't know how out of sync fuel injected bikes can get but if you can get your hands on a balancer then its worth a shot

 

double check your map sensor connection and make sure the lines not getting bent. the map sensor is on the left side of your airbox looking down at it on the bike. you might need to replace it. mine was doing exactly what your describing and it turned out the line wasnt connected at all.

Ive just gotten my throttle bodies synced and the **** looked like a stair case on the machine. none of mine were in sync. the bike runs alot smoother now for sure.

 

use a 9 volt battery and an air compressor and clean your injectors. when you apply 9 volts to the injector it opens fully, just blow air through it and it will clean it out. If i remember correctly tahts how we did it to mine.

 

I've never used seafoam before...not sure what it does. I think I'm gonna go thru mine, run some heat, make sure everything is nice and tight, maybe swap in new plugs, .....the whole nine yards. Gotta make it ready for the summer.

 

im pretty sure it was all hooked up and a new map sensor is 104 bucks from servicehonda.com

 

get new plugs. the proper ones, not the cheap ngks.. and then do the throttle bodies. itll run like a champ.

 

what are you considering the proper plugs and the ngk's are now 16 bucks a piece at a retail shop and a dealership, also what do you mean do the throttle bodies? as in sync them? will i have to take it in or is there a trick to doing them yourself?

 

Take it to the shop and have them sync the throttle bodies.. the proper plugs are like IMR9H I believe.. theyre like 18-22 a piece.