Rad Fan on 87 K75?

[gohabsgo k75]

I've had my brick for almost two months now and it just dawned on me that I haven't heard the fan turn on.  About 99% of my riding is at highway speed so maybe it doesn't need to come on but we did have a heat wave about a week ago and still nothing.    Is there an easy way to check this out? 

What's the worst that could happen if it is 'frozen'?

Larry

[mystic red]

Yea, just idle it until the needle hits the red. you'll hear it come on. Good idea to kick it on once in a while so it doesn't freeze up. It won't come on at speed but if you idle it after running it on the highway for any amount of time, it will.

[gohabsgo k75]

Yea, just idle it until the needle hits the red. you'll hear it come on. Good idea to kick it on once in a while so it doesn't freeze up. It won't come on at speed but if you idle it after running it on the highway for any amount of time, it will.

What needle are you referring to?  This is a naked 87 K75.  The only needles I have are Tach and Speedo.  Surely you don't mean to rev it up to the redline.

I'll have to try idling it for a bit tomorrow.

Larry

[TimTyler]

On the center stand, warm the engine up, then throttle to 2000rpm for a few minutes and the fan should kick-in unless it very cold where you are.

My fan sounds unmistakably like a whirring fan.

[mystic red]

Yea, just idle it until the needle hits the red. you'll hear it come on. Good idea to kick it on once in a while so it doesn't freeze up. It won't come on at speed but if you idle it after running it on the highway for any amount of time, it will.

What needle are you referring to?  This is a naked 87 K75.  The only needles I have are Tach and Speedo.  Surely you don't mean to rev it up to the redline.

I'll have to try idling it for a bit tomorrow.



Larry

Sorry, you don't have temp gauge. :embarass: Idling will still work.

[frankenduck]

Just let it idle.  If the overheat light in the instrument cluster comes on before the fan does then turn it off because that means you've got issues.

Don't worry about overheating the engine.  It has a radiator cap like a car that will blow before the engine is damaged.  Definitely turn it off if the radiator cap blows.

[gohabsgo k75]

I didn't get to ride much since my last update and didn't have a chance to idle much.  I did try idling in the garage briefly but did not hear the fan switch on.  The red light indicator did not come on either.  I have a good ride home after work ~60 miles in warm weather today.  I'll let it idle when I get home for a while.  How long should it take to turn the fan on? 

One thing I did notice, is when I idle in neutral, the engine knocks quite a bit.  If idling in gear, it does not.  Is that normal or something to worry about?

Cheers,
Larry

[mystic red]

Before the red light comes on.....

[Rick G]

Probably need to idle for 5-6 mins and as to the knock when it happens pull the clutch lever in and find if the noise goes away.

[mystic red]

If idling in gear, it does not.

[gohabsgo k75]

Probably need to idle for 5-6 mins and as to the knock when it happens pull the clutch lever in and find if the noise goes away.

Idling with it hot, still does not turn on my light, so I assume that the cooling system must be working.  I just can't hear the fan turn on/off.  As to the knocking, it stops as soon as I pull the clutch in.

Regards,
Larry

[Rick G]

If the fan was turning on/off you would hear it there is no mistaking it.
If the fan isn't turning on it will overheat at idle unless its a very cold day. The fan comes on at 103degC and the light at 111degC.
The noise disappears when the clutch lever is pulled in probably means you have a clutch problem but not being able to see/hear it would pay to have someone who knows Ks to listen to it.

[pallum]

A "whacka-whacka" at idle in neutral will be a worn transmission input shaft, but as long as it's still shifting well I wouldn't worry about it yet.

[gohabsgo k75]

If the fan was turning on/off you would hear it there is no mistaking it.
If the fan isn't turning on it will overheat at idle unless its a very cold day. The fan comes on at 103degC and the light at 111degC.
The noise disappears when the clutch lever is pulled in probably means you have a clutch problem but not being able to see/hear it would pay to have someone who knows Ks to listen to it.

The knocking only occurs after a ride.  When starting up, it does not knock at all. 

[gohabsgo k75]

A "whacka-whacka" at idle in neutral will be a worn transmission input shaft, but as long as it's still shifting well I wouldn't worry about it yet.

Shaft looked good a few weeks ago when I did the spline lube.  Only get the knock on a hot engine, not when first starting it up.

Larry

[pallum]

Probably just the transmission oil being thinner with heat, see how it is with miles though. No shifting issues, no problem!

[gohabsgo k75]

OK, I MIGHT be hearing the fan, but to me, it sounds more like the fuel pump whirr.  In any case, the red warning light does not come on, so that is good.

Cheers,
Larry

[DRxBMW]

OK, I MIGHT be hearing the fan, but to me, it sounds more like the fuel pump whirr.  In any case, the red warning light does not come on, so that is good.

Cheers,
Larry

For starters, the fan is much LOUDER than the FP sound byte.

You can physically sense the air being pushed !