Temp gauge question

[Grez007]

Heya all, finally got a short shakedown ride in today after all the winters work. All the reading ive done on this site has made the $12 membership the best investment I've made in a long time. Anyhow, bike rides pretty good, yes the brakes are pretty weak as alot of people have pointed out about the mk1, but all in the bike is running really well. So the question that ive got is about the temp gauge which alot of people say theirs run near the top of the operating range, but mine seems to not want to even get to the halfway point. I was only out for 25-30mins on rural roads, so maybe it didnt have a chance to get hot enough? I'd like to make sure the fan will come on when hot, how long would it have to idle before the fans come on?

[snyper316]

Heya all, finally got a short shakedown ride in today after all the winters work. All the reading ive done on this site has made the $12 membership the best investment I've made in a long time. Anyhow, bike rides pretty good, yes the brakes are pretty weak as alot of people have pointed out about the mk1, but all in the bike is running really well. So the question that ive got is about the temp gauge which alot of people say theirs run near the top of the operating range, but mine seems to not want to even get to the halfway point. I was only out for 25-30mins on rural roads, so maybe it didnt have a chance to get hot enough? I'd like to make sure the fan will come on when hot, how long would it have to idle before the fans come on?

 

My fan generally kicks on within 10-15minutes. Now If I am riding it maybe a few miles, and it generally stays on once it kicks on I believe I really haven't paid attention to it. Plus it is pretty quiet In my opinion. At least to a cars electric fan, I couldn't hear my mustangs kick in after I got dual exhaust installed. I do know when the bike is idling I hear a relay kick it on and can hear the fan hum just a bit...

[bongobobny]

Ummmmm, maybe somewhere along the line somebody took your thermostat out??

[MiCarl]

The gauge on my '89 typically only rises about 1/3 so long as I'm moving. Stop and go it can go all the way to the red line where the fan kicks in.

 

I think what you're referring to is the posts about at which temp the fan kicks in, not where the motorcycle usually operates.

 

It'll have to idle for a long time for the fan to kick on, especially on a cool day. When the gauge just reaches the red the fan should kick on.

[Grez007]

Ummmmm, maybe somewhere along the line somebody took your thermostat out??

 

I was kinda wondering this myself, it has had several po's. if it doesnt have one i would assume that if i let it idle long enough it will still get hot enough for the fan to come on eventually right? I just havent let it sit idle long enough maybe

[MiCarl]

I was kinda wondering this myself, it has had several po's. if it doesnt have one i would assume that if i let it idle long enough it will still get hot enough for the fan to come on eventually right? I just havent let it sit idle long enough maybe

 

Eventually. The Thermostat doesn't keep the temperature down, it tries to keep the temperature up to a minimum level.

 

I had the instrument cluster off/apart on mine. When I reassembled this morning I started it up to make sure the temp gauge worked and it came off the peg in just a couple minutes. If you have a thermostat installed it should do the same. Once it reaches the thermostat temperature the rate of increase will slow because the thermostat lets coolant circulate through the radiator.

 

The radiator is large enough it dissipates a lot of heat, even when still and without the fan on. At idle it'll take a long time to get hot enough to turn the fan on.

 

It's very rare my fan comes on, only in stop and go riding. You know when it does not by the sound but by the skin blistering on your legs.

[CaseyJ955]

I have only had the 89 but have read that the MKI bikes normally read very high and that this was theoretically corrected with the MKII. On my 89 it rarely goes over half, I think I saw it hit 2/3 once while it was sitting idling on the center stand while I adjusted carbs and MAP sensor for over 30 minutes, it took forever for the fan to decide to kick on. This was with ambient temps around 65-70.

[camos]

I have only had the 89 but have read that the MKI bikes normally read very high and that this was theoretically corrected with the MKII. On my 89 it rarely goes over half, I think I saw it hit 2/3 once while it was sitting idling on the center stand while I adjusted carbs and MAP sensor for over 30 minutes, it took forever for the fan to decide to kick on. This was with ambient temps around 65-70.

On my 89, the temp sits below half, somewhere just above 1/4, while on the highway in 60F ambient temps so about the same as yours. In "normal" city traffic, light stops etc. it gets to around half or a bit above. In heavy traffic/stops the temp gets to about 3/4 to the red.

 

There have been a couple of times when idling on the stand for a long while the fan has not kept it out of the red. One time it boiled over. Nothing like the smell of anti-freeze cooking.

[flyday58]

Heya all, finally got a short shakedown ride in today after all the winters work. All the reading ive done on this site has made the $12 membership the best investment I've made in a long time. Anyhow, bike rides pretty good, yes the brakes are pretty weak as alot of people have pointed out about the mk1, but all in the bike is running really well. So the question that ive got is about the temp gauge which alot of people say theirs run near the top of the operating range, but mine seems to not want to even get to the halfway point. I was only out for 25-30mins on rural roads, so maybe it didnt have a chance to get hot enough? I'd like to make sure the fan will come on when hot, how long would it have to idle before the fans come on?

Without knowing your history with the bike (haven't been here much the last year) I'd agree with the others. The only other thing I'd check is the bypass valve. My 83 was on bypass when I first got it running and never got very warm. I was told on this site to check it and once I took it off bypass temps acted normally for this year, on the toasty side with the fan kicking on in stop-and-go traffic. Good luck.

[Venturous Randy]

Ditto on the bypass valve. That is the plastic hex nut below the radiator. When you are looking at the hex, the tops of the letters should be pointing toward the 5 o:clock position. You should at least eliminate this first.

Randy

[videoarizona]

+3 on bypass. Make sure you loosen little screw before trying to turn valve. If you aren't familiar with how valve works, search older posts. There are pics... maybe in 1st gen tech area... that shows proper orientation.

 

My 89 runs around 1/3rd at highway. Just above half at normal stop and go city stuff. And 3/4 in Arizona summer city traffic stuff. Fan kicks in around 3/4.

And yes.. It's pretty quiet.

 

But like a fuel gauge, the temp gauge can vary from bike to bike.... Just because it can.