Hey all, new problem developed with my F4i just this last week. I've had it for about a month mostly trouble free (had to adjust the ape cct and that's it). Previously it would start up when cold and the idle would go up to about 3k, as it should, however as of about a week ago it no longer does this. The bike idles under 1,000 rpms when it's cold and it runs pretty weak, takes a bit of extra throttle to be able to take off and even then it's pretty boggy. Once moving it runs like normal and once warmed up it runs amazingly, pulls super hard and doesn't feel like it's lacking power or anything, super smooth and responsive as always. Bike is stock except for an M4 slip on. I pulled the seat off and stuck a paper clip in the little diagnostic wire (not sure what it is technically called) and the bike showed 2 codes, one was "18" which is a faulty cam pulse generator but is supposedly only for if the engine doesn't start or run, maybe an old code? the other was a 9 which is faulty air intake sensor or wiring. I'd pin it on the AIT sensor except that our bikes don't run their automatic choke (and yes, they do have a choke) off of that as far as I know, we have a wax unit that runs off coolant temperature. Could this be caused by a bad (or going bad) FPR? Or is it possible that my wax unit has actually failed (I guess this doesn't happen often)? Help me troubleshoot here! Thanks

 

I don't know about the fault codes or the sensors. But under 1000 rpm's stationairy is too low. Around 1300/1400 is better.

 

Have you checked your coolant level?

 

It idles fine when warmed up. It is only under 1000 when it is cold because the automatic choke is not kicking in.

Coolant level is normal.

 

The Wax Unit operates the Starter Valves. It's a mechanical operation. I can't imagine the Wax Unit is bad (it's certainly possible), but having something come loose or bound up is more likely. There are several screws on that assembly. I think you're going to have to look closely at the operation to figure out what's wrong.

 

The wax unit pulls the idle down with coolant temperature. If it was bad, your idle would be high all the time. Check for leaky vacuum lines, FPR, and plugs. Did this happen right after you adjusted the CCT? Cam sensor code with that suggests that your timing may be off?

Have you tried turning you idle up a little by the adjuster screw? Maybe it backed off or someone is having some fun with you...

 

I haven't had a chance to pull the bike apart yet and check all connections, will do that asap and report back with results. Okay glad to know it's most likely not the wax unit, I'll check my idle screw as well, but I don't think that's an issue as it idles right at 1400 once up to operating temp. Only other issue is that occasionally the bike will hesitate for a few seconds taking off from idle, doesn't happen often, maybe once or twice a week and I ride multiple times every day. This happened a few weeks after the CCT adjustment, and aside from no auto choke and hesitation every now and then the bike runs absolutely flawlessly and super smooth so I don't think the timing would be off. My dad said the exhaust smells rich and I've been kind of thinking that too, but I'm not experience enough around vehicles to recognize all the different exhaust smells yet. So maybe it's the FPR going bad. Thanks for the suggestions everyone!

 

Definitely sounds like the fpr. How long do you ride at a time? Mine would start up similar, then after about 20-30 minutes of straight riding, it would want to choke out at idle

 

I'm hoping it's the FPR, kind of spendy but easy fix. Probably is going to foul my plugs if I keep riding it like this. I ride anywhere from 10-30 minutes most of the time just commuting and running errands, once it's warmed up there aren't any problems I've noticed. Haven't had it out on a long ride since this started yet though so I can't say for extended amounts of time. One thing to note is the bike seems to take an extra crank or two to start and sort of sputters to life rather than starting right up like I've noticed most F4is do in youtube videos. Only when it's cold though.

 

Alright had a chance to pull the bike apart today. FPR tested to be good, no loose hoses or anything either. Other suggestions?