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1Back to top Go down   1991 K75C - Overhaul. Empty 1991 K75C - Overhaul. Sun Apr 12, 2015 9:16 am

88

88
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So I finally got brave and dug the K75C out of storage yesterday. It doesn't need much to get sorted for summer so I will do that first and then tackle it more in the winter...

Unloaded beside big Brother... 
1991 K75C - Overhaul. 2015-012

Trying the comfort seat I scored on Ebay....Looks Nice, Feels good too!
1991 K75C - Overhaul. 2015-013

First job is to sort a hole in the tank. Devcon putty and Aluminium Body repair mesh is my preferred formula.

1991 K75C - Overhaul. 2015-014

After a few minutes cleaning....
1991 K75C - Overhaul. 2015-016



Last edited by 88KE on Fri Nov 20, 2015 5:48 pm; edited 1 time in total


__________________________________________________
1991 K75C - Overhaul. Ir-log1188....May contain nuts!1991 K75C - Overhaul. Ir-log11

"The world is a book and those who do not travel read only one page." - St. Augustine from 1600 years ago & still true!

K1 - 1989 - AKA Titan (unique K1/K1100RS hybrid by Andreas Esterhammer)
K1100RS - 1995. AKA Rudolf Von Schmurf (in a million bits)
K100RS - 1991 AKA Ronnie. Cafe racer project bike
K75RTP - 1994
K75C - 1991 AKA Jim Beam. In boxes. 
K1100LT 1992 - AKA Big Red (gone)
K100LT - 1988 - AKA the Bullion brick. Should never have sold it.
    

2Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Sun Apr 12, 2015 10:54 am

charlie99

charlie99
VIP
VIP
fantastic news Will

good riding to you

shes a sweet little girl that one


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

3Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Thu Apr 16, 2015 12:21 pm

88

88
Life time member
Life time member
I was disappointed to see that the petrol which leaked for the hole in the tank dissolved the injector cover before my eyes and had attacked the plastics before I could wipe it away leaving it melted and with a rubbery texture. I can't believe it's so incompatible with petrol given it's function and location. I guess that's why so many bikes are missing them.


1991 K75C - Overhaul. K75_in10



The P.O. was "gifted" but not in a Christmasy way.

1991 K75C - Overhaul. Img_3010

Two connectors on one wire Rolling Eyes 

The radiator cover - tank stud was broken off from a drop, someone had tried to glue something in it's place. Needless to say that didn't work and the piece is FUBAR. 

1991 K75C - Overhaul. Img_3011

I had purchased this piece off Ebay as a replacement....the metal bits have been stripped as they are rusted out but the plastics are in Nice condition..
1991 K75C - Overhaul. Img_3012

The tank repair is done now just needs sanding and painting when fully cured...
1991 K75C - Overhaul. Img_3013


__________________________________________________
1991 K75C - Overhaul. Ir-log1188....May contain nuts!1991 K75C - Overhaul. Ir-log11

"The world is a book and those who do not travel read only one page." - St. Augustine from 1600 years ago & still true!

K1 - 1989 - AKA Titan (unique K1/K1100RS hybrid by Andreas Esterhammer)
K1100RS - 1995. AKA Rudolf Von Schmurf (in a million bits)
K100RS - 1991 AKA Ronnie. Cafe racer project bike
K75RTP - 1994
K75C - 1991 AKA Jim Beam. In boxes. 
K1100LT 1992 - AKA Big Red (gone)
K100LT - 1988 - AKA the Bullion brick. Should never have sold it.
    

4Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Thu Apr 16, 2015 4:21 pm

92KK 84WW Olaf

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Life time member
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Its coming along nicely........better than mine. Looks like it will be TacKled in 6 weeks to the day!!

Is that a Frisbee holder? That's one up on a cappuccino machine.....

https://servimg.com/view/16818459/482


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

5Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Thu Apr 16, 2015 4:39 pm

92KK 84WW Olaf

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Life time member
Life time member
That petrol vapour must have put you off track as you ended up with this...

1991 K75C - Overhaul. 40283544


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

6Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Thu Apr 16, 2015 8:49 pm

88

88
Life time member
Life time member
Thats a dual purpose frisbee...Used right way up it entertains the kids, use upside down it hold screws and washers and such for my K !  1991 K75C - Overhaul. 723598


__________________________________________________
1991 K75C - Overhaul. Ir-log1188....May contain nuts!1991 K75C - Overhaul. Ir-log11

"The world is a book and those who do not travel read only one page." - St. Augustine from 1600 years ago & still true!

K1 - 1989 - AKA Titan (unique K1/K1100RS hybrid by Andreas Esterhammer)
K1100RS - 1995. AKA Rudolf Von Schmurf (in a million bits)
K100RS - 1991 AKA Ronnie. Cafe racer project bike
K75RTP - 1994
K75C - 1991 AKA Jim Beam. In boxes. 
K1100LT 1992 - AKA Big Red (gone)
K100LT - 1988 - AKA the Bullion brick. Should never have sold it.
    

7Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Fri Nov 20, 2015 7:39 am

88

88
Life time member
Life time member
An update on the project.

At the end of last May Tackler arrived from Aus to take the K75 on a lap of France and the Alps (well documented elswhere in the forum)

In preparation for his visit the bike needed a bit of attention:

Steering/Head bearings shot - replaced.
Front calipers seized - Replaced.
Battery shot - Replaced
Fuel pump Kaput - Replaced with a known good one.
Broken Centre Stand - replaced.
Standard Bench seat was ripped - replaced with a comfort seat
New Tyres (Pirrelli Sport Demons fitted)
Panniers from the LT were fitted for the trip.
Windscreen and brackets acquired and fitted.



1991 K75C - Overhaul. Dscf1210

There was evidence of oil in the water and that was cleaned out as best we could at the campsite but the problem would return later due to the fan not working and the bike overheating.

Tackler's later trip was marred by a sticking sprag clutch thankfully he was in the mountains so had gravity on his side for bump starting.

Last week I returned to Rouffignac to collect the bike. It fired on the second go and just needed a top up of tyre pressures and fluids before I rode it back to Ireland. There was a tiny amount of oil foam in the header Tank. I reconed this might have come from rad fins after the last flush as we hadn't removed the rad.

The sticking Sprag clutch returned on day 2 or the ride to the ferry and is now well and truly stuck so it will have to come out.

The issue that exercises my mind  most however is the oil in the waterway. We had concluded that the previous owner being a truck mechanic and not having had a bike since the 70's put oil in the cooler expansion bottle, mistaking it for an oil resevoir. It appears to have gotten no worse during Tacklers 2 odd k miles in the alps. 

Not being able to shut the bike down at the ferry post (it was too flat for me to contemplate bumping it!) and with a sticking fan motor it overheated again and a fair amount of foam blew out the top of the bottle (The cap had been conveniently nibble away by some French mice for that Volcanic effect!).

I have to suspect the head casket is toast but the bike runs beatifully smoothly and economically and has given no impression otherwise ovevr the past 4 k miles. 

So I need some advice please:

Is it possible the heat is opening up the gasket between oil and waterways when getting too hot? 

Is there another possibility I'm overlooking.

I will check the head torque values and failing that may have to remove the head for a new gasket. 

Could the bike run so well for so long with plenty of fast motorway work with such a head gasket issue?

All input appreciated



Last edited by 88KE on Fri Nov 20, 2015 5:48 pm; edited 1 time in total


__________________________________________________
1991 K75C - Overhaul. Ir-log1188....May contain nuts!1991 K75C - Overhaul. Ir-log11

"The world is a book and those who do not travel read only one page." - St. Augustine from 1600 years ago & still true!

K1 - 1989 - AKA Titan (unique K1/K1100RS hybrid by Andreas Esterhammer)
K1100RS - 1995. AKA Rudolf Von Schmurf (in a million bits)
K100RS - 1991 AKA Ronnie. Cafe racer project bike
K75RTP - 1994
K75C - 1991 AKA Jim Beam. In boxes. 
K1100LT 1992 - AKA Big Red (gone)
K100LT - 1988 - AKA the Bullion brick. Should never have sold it.
    

8Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Fri Nov 20, 2015 8:03 am

mike d

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Life time member
Sounds like you need to perform a compression and leak down test to see if it is from the head gasket.

Mike

    

9Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Fri Nov 20, 2015 8:12 am

92KK 84WW Olaf

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Life time member
Will

The only place to relieve the excess pressure from overheating is through the expansion tank. My recollection is that you did not have to keep topping up, remembered as I read this post about another one dealing with sticky radiator caps. If the cap is bunged up couldit  cause over pressure that suddenly releases into the expansion reservoir as steam instead of hot coolant if temperature is above the boiling point? Maybe swap with the LT one and see what happens?

I did have a car one time did this but it was a head gasket and it was drinking coolant. The K75 doesn't seem to be losing coolant?


__________________________________________________
1992 K100LT 0193214 Bertha Blue 101,000 miles
1984 K100RT 0022575 Brutus Baja Red 578 bought 36,000 now 89,150 miles
1997 K1100LT 0188024 Wotan Mystic Red 689 58,645 now 106,950 miles Deceased.
1983 K100RS 0011157 Fricka 606 Alaska Blue 29,495 miles Damn K Pox Its a Bat outta Hell Now 58,200 miles. 
1996 K1100LT 0233004 Lohengrin Mystic Red 38,000 miles currently 51,800 miles.
1983 K100RS 0004449 Odette R100 colours 58,000 miles. Sprint fairing now 63,390 miles

Past:
1968 Yamaha 80 YG1
1971 Yamaha 125 YAS-1
1968 Honda 125 SS
1970 Honda CD 175
1973 Honda CB500-4
Honda CX 500
    

10Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Fri Nov 20, 2015 7:57 pm

K75cster

K75cster
Life time member
Life time member
Perhaps the impeller is spinning but not flowing the fluid, and that there, is a good place for oil and water to mix too, after the compression test maybe consider the pumps


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

11Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Sat Nov 21, 2015 3:57 pm

88

88
Life time member
Life time member
We considered the pump Keith, then dismissed it as there's nothing showing at the weep hole. I'll run the compression test first.


__________________________________________________
1991 K75C - Overhaul. Ir-log1188....May contain nuts!1991 K75C - Overhaul. Ir-log11

"The world is a book and those who do not travel read only one page." - St. Augustine from 1600 years ago & still true!

K1 - 1989 - AKA Titan (unique K1/K1100RS hybrid by Andreas Esterhammer)
K1100RS - 1995. AKA Rudolf Von Schmurf (in a million bits)
K100RS - 1991 AKA Ronnie. Cafe racer project bike
K75RTP - 1994
K75C - 1991 AKA Jim Beam. In boxes. 
K1100LT 1992 - AKA Big Red (gone)
K100LT - 1988 - AKA the Bullion brick. Should never have sold it.
    

12Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Sun Nov 22, 2015 4:24 am

K75cster

K75cster
Life time member
Life time member
I've not pulled the pumps apart before, so cant say if they can leak between the two and not out the weep hole, I guess there is only two places for the oil to catch up with the water and that would be the head gasket and the pumps, so if its the head gasket would it not be boosting the pressure in the water? maybe a pressure test of the water may help it pass into the combustion chamber and by removing the plugs maybe have some water mist out when cranked over under pressure??? Anyone know of a safe pressure that might be done at??


__________________________________________________
Keith - 1987 K75c with r100rt replica fairing and half of a 1984 K100rt 1992 K1100LT a blue one

The Clever are adept at extricating themselves from situations that the wise would have avoided from the outset - QUOTE from david Hillel in Out of the Earth.
    

13Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Sun Nov 22, 2015 5:27 am

charlie99

charlie99
VIP
VIP
Will don't discount the pump assembly

we have seen before that the weep hole can get blocked ...additional oil through the pump seal could accumulate further blocking the weep hole completely

next thing to happen is the pressure from the pump far exceeds the water pressure and might bleed into the impeller assembly

my best guess is to replace the pump seals and see what happens after

during this process ...a fair bet might be that the weep hole WILL be blocked

hope it gets resolved simply Will

good luck mate


__________________________________________________
cheezy grin whilst riding, kinda bloke ....oh the joy !!!! ...... ( brick aviator )

'86 K100 RT..#0090401 ..."Gerty" ( Gertrude Von Clickandshift ) --------O%O
'86 k100 rs.. #######..  "Fred " (f(rame) red ) ( Fredrick leichtundschnell ) - -
bits and pieces from many kind friends across the k100 world ...with many thanks ..
1987 k100rs ########   "Red"  - (red sports rs TWB style )
1989 K100rt #009637   "Black Betty"  (naked rt ala Nigel , now sporting an rs main fairing )
    

14Back to top Go down   1991 K75C - Overhaul. Empty Re: 1991 K75C - Overhaul. Sun Nov 22, 2015 6:42 am

Rick G

Rick G
admin
admin
+1 on what Charlie said.
If that weep hole is blocked and it is easy to happen when the oil seal leaks the easy path is into the coolant. I have fixed 3 or 4 like that over the last few years.
When fixed put a teaspoon of soluable oil in the coolant (just water) and run for a few days then drain, flush and refill with the green stuff or whatever you usually use.


__________________________________________________
"Man sacrifices his health in order to make money.
Then he sacrifices money to recuperate his health.
And then he is so anxious about the future that he does not enjoy the present; the result being that he does not live in the present or the future; he lives as if he is never going to die, and then dies having never really lived."   Dalai Lama


Bikes 1999 K1100 LT with a Big Block 1200
    

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