CBR250RR doesn't heat up

[DuCKy!]

Hi all!

I searched the whole internet for my problem!!
New to bikes, just got a 1990 MC22 done 28,000k's. Everything's mint apart from some cracked fairings.

Anyways, when I started it and let it idle for 5 mins, nothing happens on the temperature gauge. So I decided to take it for a slow ride.
Another 10 minutes later, the temperature goes to just past the big thick bar by the "C" symbol on the gauge. Decided to get the revs up to around 11k or so.
Another 5 minutes later it's gone up just a tad and that's about it.

From my car knowledge, this points to a rooted thermostat.
Am I correct to assume so?

Cheers
Nicholas

[Rhys]

I think you will find that it is at the right temp, the gauge should be on about 1/4

[Big Dog]

Hi all!

I searched the whole internet for my problem!!
New to bikes, just got a 1990 MC22 done 28,000k's. Everything's mint apart from some cracked fairings.

Anyways, when I started it and let it idle for 5 mins, nothing happens on the temperature gauge. So I decided to take it for a slow ride.
Another 10 minutes later, the temperature goes to just past the big thick bar by the "C" symbol on the gauge. Decided to get the revs up to around 11k or so.
Another 5 minutes later it's gone up just a tad and that's about it.

From my car knowledge, this points to a rooted thermostat.
Am I correct to assume so?

Cheers
Nicholas

The delay in temp increase is that you are measuring the temp of the water on the cold side of the thermostat.
That this goes up after a period indicates your thermostat is working.

Unless you can feel heat coming out from the fairings I wouldn't panic.

Most bikes of this era barely register on the temp gauge unless in stop start traffic( no air flow), you thrash it or there is a problem.



Stupid phone / Tapatalk, apologies in advance.

[The Pastor]

does the fan kick in?

Check the thermostat is still in there, some people take them out.

[DuCKy!]

The Pastor: I didn't notice if the fan kicked in or not. From what I've read around, the fan only kicks in when the gauge is at 3/4 to Hot.

Big Dog: I didn't realise that the thermosensor is on the cool side of the thermostat! That makes sense in regards to the huge delay in temperature increase, although I don't know why they designed it like this, unlike motorcars?

I'll warm it up, and take it for a longer ride. Will keep note of the time I've rode, as well as snap a pic of the gauge when I park up.

[AllanB]

1. don't idle the thing for 5 minutes. That is not good for your engine. Fire it up chuck on the helmet and gloves (I'm presuming you have your other riding gear on) and ride. just take it easy for the first few kms while the engine warms it's self up.


At normal operating temp the Honda's tend to read at the low end of the temp gauge - you'll notice it rise when idling at a traffic light for a long duration or when stuck behind traffic heading up hills.

[DuCKy!]

1. don't idle the thing for 5 minutes. That is not good for your engine. Fire it up chuck on the helmet and gloves (I'm presuming you have your other riding gear on) and ride. just take it easy for the first few kms while the engine warms it's self up.

I never let my cars idle to warm up. However I've seen people religiously suggesting to warm up at idle for 5 mins as the older engines "need" that warm up phase.

I'll go with your instructions

[Big Dog]

I warm to a smooth idle. Usually as long as helmet and gloves plus reversing to where I usually put it in gear on a cold morning.


Stupid phone / Tapatalk, apologies in advance.

[neels]

I never let my cars idle to warm up. However I've seen people religiously suggesting to warm up at idle for 5 mins as the older engines "need" that warm up phase.

I'll go with your instructions

Idling warms your engine very slowly, while the oil is still finding it's way around and nothing is up to it's designed operating temperature. Just remember it's not a 1950's Morris that needs warming up so the poxy old carb works properly.

[Erelyes]

Idling warms your engine very slowly, while the oil is still finding it's way around and nothing is up to it's designed operating temperature. Just remember it's not a 1950's Morris that needs warming up so the poxy old carb works properly.

1 out of 3 it's. I'll take that.

Seriously though, the increased wear you get from 5 minutes worth of idling is going to be far and above any wear you get because the thing's still 'warming up' as you ride.

[AllanB]

the 'old' 5 minute warm up comes from absolute decades back - heavy weight single rate oil, poorer machining tolerances etc. Your modern water cooled car manual will tell you NOT to do a lengthy warm up. Same applies to the bike. Just take it easy through the revs until it reaches temp.

Good question though.

[hayd3n]

what ???? ive been cranking and thrashing my bike for almost 4 years now , now you say i should warm it up??
i guess 117,000 kms is almost run in lol,
seriously tho leaving you bike on its sidestand and warming up is not good for it think about how the oil is flowing around your engine on its side and barely pumping over the cams

[nzspokes]

All this talk of warming up. Meh.

Neighbors have a prem baby, If I start it and warm it up I would wake the kid. I roll down the drive and start it on the street and away I go.

My bike is not subtle.

[DuCKy!]

Alrighty, point taken! No "warming up for 5 mins".



Does this look alright? This was after a good amount of riding.

[nzspokes]

Yup, thats fine.