Speedometer Temperature Gauge on a '93 CB400 Super Four

[chanzhf]

Hi guys,

I've chanced upon this forum and looking through the posts, there are some very knowledgeable people on the CB400 here.

A bit of a back history, I'm the 11th owner of a year 93 CB400. When I got it it was in terribad condition. My mechanic and I did a fair amount of work to get the bike into a very presentable state.

Forward to now, I've got new set of Chinese-made OEM Speedometers into the bike. Something that has been bothering me is that the temperature needle on the Chinese Speedos never seem to work. Its just like a dead fish. Whereas on the original Japanese one (which is heavily damaged), based on memory, the needle seem to work just fine.

Would anyone be able to advise on how the temperature gauge on the CB400 '92-'94 works? I am going to assume there is a temperature sensor somewhere, with a corresponding temperature gauge in the speedometer. This is one of those things where it is a minor inconvenience to me, but makes me rather uncomfortable due to the amount of time and effort I've spent into sorting out other aspects of the bike, all of which has turned out great.

Here's a picture of my bike

[royster81]

My mate is in the same boat so I'll be following this closely, his clocks where knackered when he bought his and the temperature needle doesn't move on his new Chinese clocks.
On a slightly different note, that's a lovely looking bike, did you just get it recently? Like just before Christmas?

[chanzhf]

Hi there,

I got this bike fairly recently. A couple of months before Christmas. As you can tell from the reg plate of the car, I'm in Northern Ireland too. Are you going to tell me something about the history of this bike? Heh

[royster81]

Just that you got to the buyer before I did lol. I saw it advertised and rang but he told me someone was on their way then later that night he text back to say it was sold
I hope you get it sorted and on the road soon
Where abouts in Belfast are you? I'm over near forestside

[Devon462]

I think the temperature sensor is on the left hand side of radiator (as you are sat on it ). I will get a photo tomorrow's in the daylight as I've got a 93 cb400 as well.
It is a nice looking bike, where did you get radiator cover and red panels on the side?

[royster81]

https://www.google.co.uk/url?sa=t&sourc ... xiOnw8Ygiw

I think the sensor on the left hand side of the radiator is the fan switch.
F31 on the parts fiche shows the cooling system and the thermostat housing looks like it has the a temperature sensor part 24 I think.

[SevenThreeSeven]

Japanese motorcycles of the age of your Superfour usually have a single-wire temperature sensor mounted in the same housing as the thermostat. The thermostat housing is usually separate from the radiator. The only sensor that is usually mounted on/in the radiator is the radiator fan control switch. If you or your mechanic has accidentally attached the instrument panel temp gauge to the radiator fan control switch it just won't work.

[royster81]

Maybe the resistance is off in the clocks

[chanzhf]

Royster81: I occasionally do my shopping from the Sainsbury at forestside, say hi if you see me or the bike. I'm usually around the hospitals in Belfast We both got attracted by the price tag of the bike I assume, however, with the added servicing/mods/repairs carried out on the bike thus far, you might probably find the total cost to be quite uneconomical.

Moving on to the temperature aspects, I thought the temperature thing on the radiator was just simply a thermostats that kicks the radiator on when temperature soars. I can get a new thermostat in, its cheap stuff, but I am not sure if that's the thing that's making the instrument panel/speedo/clocks/temp gauge not work.

[chanzhf]

The clocks that I got are pretty idiot-proof. It is just 2 male plugs that connects to two different female parts of the existing wire harness. I'll get some pictures in a short while.

The only solution I can think of in the short term would be to perform a full transplant of the temperature gauge from the original knackered Japanese set onto the Chinese set. Seeing as how the Chinese made clocks actually work well (sans temperature gauge), I am trying to avoid that route due to concerns about accidentally ruining them.