noisy k75

de crowe · Apr 3, 2014

I recently acquired a 1993 reg k75. real oem suggests it was manufactured in late 1991 chassis number 0251519
In any event there is a nasty rumbling/ deep rattling noise toward the rear of the engine around the alternator area. I though it might be a fecked alternator but it seems to be charging as normal, producing around 12.5 volts on the multimeter. any suggestions as to what it might be. Kinda hoping it might have been the alternator as otherwise it might be bearings or some such horror.
Also the cooling fan does not working thus when it over heats it spits out coolant at the expansion contain/reservoir.

I am not too familiar with this model. round head light rubber thing at front of seat on tank, either does not have or is missing side panels,

Any thoughts.

de crowe · Apr 3, 2014

picture

a photo,
warning light on for abs, flashing centre and left

can't load photo!

Jaws100 · Apr 3, 2014

De Crowe's Photo of K75

Smug · Apr 4, 2014

A good alternator should be giving you more than 12.5 volts.

seahorse · Apr 4, 2014

Take off the alternator and check drive cup and rubbers. Rubbers break up and vanes in drive cup can break.

DrFarkoff · Apr 4, 2014

I tried to poste this last night but the site kept telling me my token had expired

K75's have a bad habit of breaking alternator drive fins

Just inside where the frame makes a v just above the footrests on the right side

Take out the battery undo the spade and one wire on the alternator and undo the bolts around it and slip it back

There should be cush drive type rubbers separated by 3 alloy fins you'll probably find them broken

You can see the alternator drive "dog" in some pics here don't worry that's a K1200RS you can do yours through the battery box

Ogmios · Apr 4, 2014

... I am not too familiar with this model. round head light rubber thing at front of seat on tank ...

Model; K75C.
low seat model, i think. Hence no side panels and the pad. :nenau

The fans seize - you might get it working just with a little lube sprayed at it and turning it by hand. :nenau

Dr. F is usually spot on with his 'diagnosis-from-a-distance' (he's done it for me often enough :blush

) and i've heard the same re; alternator drive fins.

Good Luck - keep us posted. :thumb2

de crowe · Apr 4, 2014

k75

Thanks for that Jay and Marc,
I had it stripped down yesterday so that I could get at the alternator. I might get another chance tomorrow.
The cooling fan is not kicking in either so between the suspect alternator, abs stuff an cooling fan I have clearly acquired a puppy

ianboydsnr · Apr 4, 2014

de crowe said:
Thanks for that Jay and Marc,
I had it stripped down yesterday so that I could get at the alternator. I might get another chance tomorrow.
The cooling fan is not kicking in either so between the suspect alternator, abs stuff an cooling fan I have clearly acquired a puppy

Replace the fan with a cheap universal car one, that's what we did with my brothers fazer 1000, measure the space, buy one to fit the space!

DrFarkoff · Apr 4, 2014

Fuse 7 " lufter "

Also spin the fan and see if it turns by hand if it frees up or is already free they take forever to come in even in traffic
ABS probably just a reset needed especially if you have had the battery disconnected

(RIP) Yamaha1 · Apr 7, 2014

Yep, it is either a Basic model, or the C model, with the low comfort seat - and they don't have side panels.
Totally different seat to the S model - shorter, and different fixing method.

As for the fan - could be either the connector nearby (they tend to corrode) OR the thermostat.

You haven't bought a pup - BMW's best built bike!!!

Mike

de crowe · Apr 7, 2014

Yamaha1 said:
Yep, it is either a Basic model, or the C model, with the low comfort seat - and they don't have side panels.
Totally different seat to the S model - shorter, and different fixing method.

As for the fan - could be either the connector nearby (they tend to corrode) OR the thermostat.

You haven't bought a pup - BMW's best built bike!!!

Mike

To be fair I was speaking a little tongue in cheek when I called it a puppy. It actually rides quite well and the body work is in good nick and the other issues are part of the joys of buying a relatively old, 21 years, well used cheap bike.Its condition was very much reflected in the price. It does have 80k+ on the clock.It gives me an opportunity to pretend I can be a mechanic.

I am a big fan of the K75, I have a 93 K75s which is being used within the family, and I had a K75rt until about 4 years ago.
Not the fuse, fuse ok.The fan as it appears to be stuck. It has been sitting up for a long time, an assuming the noise is the alternator, the drive is good, clutch and gearbox all seem fine.
Thanks.

de crowe · Apr 7, 2014

model

when I said i wasn't familiar with the model, I mean this particular model K75, the only other one I have seen that looks like it is the white one stunningly restored by MikeP. But even that had a fairing of sorts.

Steptoe · Apr 8, 2014

DrFarkoff said:
Fuse 7 " lufter "

Also spin the fan and see if it turns by hand if it frees up or is already free they take forever to come in even in traffic

Just bridge the fan live terminal in the temperature relay. The fan should come on.

noisy k75

de crowe

Well-known member

de crowe

Well-known member

Jaws100

Registered user

Smug

Well-known member

seahorse

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DrFarkoff

Grumpy Ole Git!!!

Ogmios

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de crowe

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ianboydsnr

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DrFarkoff

Grumpy Ole Git!!!

(RIP) Yamaha1

Well-known member

de crowe

Well-known member

de crowe

Well-known member

Steptoe

What a waste.

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