flyou that doesn't sound right your fan kicking on that late and all. i do alot of in the city riding in the dc/va/md area and it gets hot here but i never ever get above 230 sitting in traffic. my bike will feel hotter than that but my thermostat still says 230. as for draining the radiatior, i have yet to do it cause i am worried about air bubbles, but i looked in my manual. it points to where the tube going from the radiator to the engine on the left side, there is like 3 bolts on the engine. i even think one of them has arrows on it to let you know which one it is, but unscrew that and it will drain out all your coolant.

 

when's the last time you replaced your coolant?
check this out. the temp sensor sits adjacent to the thermostat. the fan switch is all the way on the clutch side of the radiator. when the temp reads XXX at the sensor/t-stat area, it's less than XXX at the switch. the switch will always turn on at a certain temp, but gunking on the switch would prevent it from reading so well.

you need to change your coolant at least 1x per year, take off that sensor (coolant will come out but nothing bad) andwipe it clean with brake or some other contact cleaner (mine was all gunked up) or just use your new one. then refill the radiator, burp it to get all the air out of the system...and see if that works.

if it doesn't, then your tstat may not be opening up completely. hence you don't get as good of a flow, so the hot coolant reaches the sensor later and later.

does this make sense?

 

Cool man, I'm going to crack it open this weekend. I need to replace the FPR anyway.

Am I correct in assuming the fan switch and the temperature sensor are independent and are in no way interconnected?

I'll replace the thermostat too while i'm in there. They're cheap... and yep, flush her once a year. Last flush was about 4 months ago.

 

Hey Flyou, you have talked about the FPR in alot of posts, where is the FPR located, and how will I know if I need to replace mine? I have 16,000 miles on my bike now. Is it located above the CCT?

 

nah it's on the clutch side next to the fuel rail behind throttle bodies. I'm going to do a write-up on replacing it this weekend. Hopefully disect my old one so we can all understand why they suck so bad.

 

cool. looking forward to seeing it. take some pics and then you can put it up in the how to section also.

 

well...if you look at how many busted FPRs are compared to how many F4is are out there without any FPR problems...they don't 'suck' they're just like any other parts that break down.

before i sold my bike i had 40k on her and she was still nice. although at times i did suspect my FPR was bad ;-)

 

Buuuuuump:

Wlep, the fan switch has been replaced and has not made any difference. The fan is still coming on wayyyy to late. I still don't believe it's a thermostat issue as the temperature drops very quickly once the fan comes on. Looks like the coolant has good flow.

I have another theory: My temperature probe (which sits next to my thermostat) is going south. I've heard it's a pretty common problem. My bike might not be overheating at all. I was riding it today down the highway and my temperature went from 185 to 170 to 175 in the span of about 5 seconds.

Asked the dealership about it, and they said that they've seen that happen quite often. The dealership also said that the thermostats in hondas are very solid. Apparently the've only sold 1 thermostat in the past 24 months. Kinda find that hard to believe but whatever.

Ugh, I'll just fix it in the spring (Or cover my temperature gauge up with tape if it's lying to me).[/align]

 

I think your worrying about something thats not that big of a deal. I used to worry about it overheating and I did nothing about it and 10,000 miles later. Its running great still.

 

yeah screw it. if it's not boiling out, i'm just gonna say '**** it'.

thinking about selling this thing anyway...