Temp Increase after shutting off bike

[jamesf]

Just bought an 05 FZ6 yesterday. Today it was about 60 degrees and I was out riding on the highway maintaining about 85-95 mph for a little while. I then got off the hwy and had a relaxed ride back to my house thru the city (about 5-10 mins). When I got home, I shut the bike off (with the kill switch) and the temp was at about 3 bars (s1 gauge cluster, so no numerical values). After I shut it off the fan kicked on (or maybe it was already on and I couldn't hear it before). Temp now at 4 bars. I'm a little concerned at this point because it hadn't done this before. Temp then climbs up to 5 bars (although I don't recall the 5th bar flashing), at which point I started the bike to get coolant flowing because I was pretty worried at that point. After I started it, temp instantly dropped to 4 bars, and then quickly after that back to three. Shut it off again after it had been at three for a little bit, and it climbed to four again, and the fan kicked on again, but it went back to three after a minute or so.

It is of course logical that coolant temp would increase after shutting the bike off, but is this much of an increase normal? I didn't notice this at all earlier in the day when riding and stopping, nor did I notice it last night when bringing it home, however it was colder and I wasn't sustaining speeds as high. Anyone else experience a similar temp spike after shutting off the motor?

Related question: Does anyone actually know what the temp bars on the S1 correspond to in terms of numerical values? I hate arbitrary scales like this.

 

[TownsendsFJR1300]

All normal...

As you noted, the engine is still hot but no coolant is flowing.

*Un-less you know for certain when the coolant was changed, wouldn't hurt to change it, flush if really nasty... I use Prestone pre-mix 50/50.

Tip, when draining, instead of using the little drain bolt (easy to strip) at the bottom of the water pump, pull the HOSE at the water pump (a bit messy), but you can clean that aluminum is (where the hose attaches).

Wouldn't hurt to do a full service (oil change, etc), "go over" on a bike new to you...:thumbup:

 

[jamesf]

Thanks for the answer. Glad to hear it's normal. Is there any value in running it for a bit after riding to circulate the coolant?

I plan on giving it a full service, oil, brake fluid, coolant, plugs, air filter, etc., if nothing else just so I have a good starting mileage for all those services I can track.

 

[TownsendsFJR1300]

Naw, not really... Really won't hurt anything un-less you overheat while riding.

Remember, that engine (and frame) is a heat sink. As you noted, once you started moving, temps dropped on it's own and when the fan kicked on, again, temps dropped (as designed)...

Not mentioned is to check the radiator overflow tank under the seat, that it's full (to the marks) cold.

*If I get stuck in heavy traffic, temps near 200F (not often), by the time I get moving, closer to home with little traffic, temps drop back to 175/ 180 or so...