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1Back to top Go down    A Krap day with another K!! on Sat Mar 11, 2017 3:32 pm

Motorbike Mike

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I've had about 8 K's and apart from one, every bike has had a leaky tank and I have another 3 in the shed to weld up.
I rescued a K1100LT that had been stood since 1995 two years back and as soon as I'd cleaned the tank out I noticed a small bubble on the bottom left-where else? Knowing this I emptied the tank before Christmas ready for further investigation which came in a moment of slight boredom (and obvious madness) this morning. I expected a pinprick but not what I found and easily the worst I've seen.











Swiss cheese springs to mind here!
I've managed to control the heat and therefore limit heat damage to the surrounding paint finish.
I'm not taking any chances so I'm using an Ethanol proof tank sealer just to be sure.

I cannot adequately convey how pissed off I am with having to fix these f*****g alloy tanks.
Owning K's is wearing very thin. Evil or Very Mad

    

2Back to top Go down    Re: A Krap day with another K!! on Sat Mar 11, 2017 4:50 pm

Dai

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Mike - if it makes you feel any better, I restored a Guzzi 1000SP last year with similar results. I lifted the fuel tank to check it before consigning it to the painters and tapped the bottom to be greeted with an ominous dull 'tuf' sort-of noise. The whole bloody righthand side bottom was only held together with paint - seriously. So I selected one of my own tanks as an interim to keep the restoration moving, did the same check but this time 'only' poked a two-inch hole in the bottom. Evil or Very Mad Evil or Very Mad Evil or Very Mad At least that one was welded up. I'm afraid to go anywhere near the other four tanks, just in case.


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'83 K100 upgraded to K100RS spec
Others...
'78 Moto Guzzi 850-T3, '79 Moto Guzzi 850-T3 California,'93 Moto Guzzi 1100ie California,
'03 Suzuki Blandit GSF600SK3 (NFS any more because wifey has claimed it)
    

3Back to top Go down    Re: A Krap day with another K!! on Sat Mar 11, 2017 7:42 pm

RicK G

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I had 8 very distinct holes on the K75RT I got last year and then some more welding on suspected places that were very close. It looked good except for the one bubble in the usual place.


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If everything seems under control then you aint goin fast enough:- Mario Andretti
Bikes 1986 K100RT, 1993 K1100 LT, 1994 K1100 LT, 1993 K75 RT, 1996 K75RT, 1986 K75 GS, 1979 Z1300 Kawasaki X 2 & 1976 SR 500 Yamaha for now
    

4Back to top Go down    Re: A Krap day with another K!! on Thu Mar 16, 2017 5:46 pm

Motorbike Mike

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With the tank welded up I'm using an Ethanol proof sealer.



This is a first for me but the tank had lots of perforations that I've welded up, there are bound to be area's that are almost through but will wait until I've repaired the paint! I've looked for another tank in the same colour but without success also, the general paintwork is fabulous so I feel that repairing both bottom sides is my best option....a job for next week.

    

5Back to top Go down    Re: A Krap day with another K!! on Thu Mar 16, 2017 7:27 pm

Snod Blatter

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Mine has a small rust patch, bottom left.. Should I be worried or Very Worried? A quick google suggests patching with resin, sounds like a neat idea.


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1989 K100RS SE ABS 8v VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850
http://justbikethings.blogspot.co.uk/
    

6Back to top Go down    Re: A Krap day with another K!! on Thu Mar 16, 2017 7:37 pm

Motorbike Mike

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@Snod Blatter wrote:Mine has a small rust patch, bottom left.. Should I be worried or Very Worried? A quick google suggests patching with resin, sounds like a neat idea.
That's exactly how my tank above started. Trust me Snod, a blister is the tip of the iceberg. Having given the matter lots and lots of thought I can't see how sticking something on the outside when the issue started inside will help.
If you can wait a week I'll let you know how I've got on and you can make your decision from there. These bloody alloy tanks!

    

7Back to top Go down    Re: A Krap day with another K!! on Thu Mar 16, 2017 7:47 pm

Snod Blatter

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I think they put the resin patch on the inside.. It doesn't help if the tank is full of pinholes though! I await your updates Sad

But how come it doesn't leak? Is it just the paint holding the fuel in? Though I wouldn't mind having mine resprayed, perhaps with petrol resistant lacquer this time! Well done previous owner, very clever..


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1989 K100RS SE ABS 8v VIN: 0149214
Others: 1.5 x Honda CBX250RS-E, '94 CB250, '95 TRX850
http://justbikethings.blogspot.co.uk/
    

8Back to top Go down    Re: A Krap day with another K!! on Fri Mar 17, 2017 5:37 am

Crazy Frog

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3 tanks, 3 similar problems. The last one that I bought has been welded. It is the best welding that I ever seen. I believe that only one side was perforated, but the welder did some preventative maintenance and welded both sides.


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

9Back to top Go down    Re: A Krap day with another K!! on Fri Mar 17, 2017 6:05 am

Motorbike Mike

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If you were to remove the paint you'll find that the tank does have hole but they are full of corroded alloy silt.If you disturb it now it will leak but a leak is now inevitable anyway at some point.
I've only ever seen the putty on the outside of tanks and never thought about placing it inside.

I've used a tank sealer before, some years back and standing petrol melted it away. I've directly asked Caswell about the product I've used and they guaranteed that it was Ethanol proof. I was going to paste their email on here but I must have deleted it. It does need to work because it wasn't cheap.
Take a look.

http://www.caswelleurope.co.uk/ethanol-proof-fuel-tank-sealer-gts1750/

    

10Back to top Go down    Update. on Wed Apr 05, 2017 5:32 pm

Motorbike Mike

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I finally got around to finishing the perforated tank from my K11. I managed to blow the colour from the bottom edge and up the tank to hide the slight difference in colour as the new paint was a shade or two out.





Lacquer flatted back and ready for polishing. That is what is called a "local repair" where the repair area is kept to the minimum possible.

If you look closely you can just see a diagonal line going up from left to right where the overspray has stopped where the tank top was bagged up and that's the trick here. If that line is light enough it's fairly easy to polish it down to fade it in to the original finish of the factory paint.




That's it finished save for a bit of polish I've not taken off. It's back on the bike now and I'll get some pics next time it's outside.

    

11Back to top Go down    Re: A Krap day with another K!! on Wed Apr 05, 2017 6:08 pm

Point-Seven-five

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Nice Job!!! Blending in on something that small can be tough.


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Present:
1994 K75RT
1994 K75S
1992 K100RS

Past:
1982 Honda FT500
1979 Honda XR185
1977 Honda XL125
1974 Honda XL125
1972 OSSA Pioneer 250
1968 Kawasaki 175
    

12Back to top Go down    Re: A Krap day with another K!! on Wed Apr 05, 2017 6:14 pm

Motorbike Mike

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@Point-Seven-five wrote:Nice Job!!! Blending in on something that small can be tough.
Thanks for the compliment but I have to admit that I have a slight advantage. I repaired car paint in that manner for over 20 years.

    

13Back to top Go down    Re: A Krap day with another K!! on Wed Apr 05, 2017 6:27 pm

Crazy Frog

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Just in case you don't know this blender for clear coat.... It works very well.
Clear coat blender


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1986 k75, 1985 K100rt, 1985 K100rt/EML sidecar.
    

14Back to top Go down    Re: A Krap day with another K!! on Wed Apr 05, 2017 7:15 pm

Motorbike Mike

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I know this type of product exists but the longer you leave the lacquer (48 hours+) the easier it is to blend the edge of the repair. A long standing time post repair is vitally important when repairing black.

    

15Back to top Go down    Re: A Krap day with another K!! on Wed Apr 05, 2017 11:26 pm

indian036

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Its amazing what plain fibreglass can do in such situations. Nearly 30 years ago, my (then) boat had some perforation in a couple of areas of the bottom of a simple rectangular steel fuel tank. Careful preparation back to metal, resin and glass mat. My son still has that boat and it hasn't leaked, though its never had ethanol fuel in it. All bets are off in that situation.
Based on that experience, I did a similar thing for a small ag bike 15 years ago. Still going as far as I know. In both cases, prettiness wasn't an issue. I'm sure Mike would have done a much prettier job.

Bill


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1985 K100RT Red. VIN 0028991K100RT ENG 104EA248523386
1985 K100RT Blue. VIN 0029036K100RT ENG 104EA25852071
1990 K100LT Black. VIN WB105060310190452
1984 K100RT White. VIN. 0023022K100RT ENG 104EA32848523
    

16Back to top Go down    Re: A Krap day with another K!! on Sun Apr 09, 2017 4:46 am

Motorbike Mike

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I've given the tank some standing time with some Super Unleaded sat in there. I figured that if anything would melt the chemical liner, that would do the trick. It is absolutely fine, the lining hasn't gone soft or melting so I thought I'd start the bike. It ran better than before due to an almost blocked fuel filter. I wished I'd taken photo's of the inside when I cut it open, I'm amazed the bike ran at all!
So, bike ticking over for a few minutes and went for a blip of the throttle but the bike dies of fuel starvation-all 4 cylinders just faded away but I can see fuel in the tank. I take the tube off and press the starter but only a light froth comes out so I decided the pump had retired. I fit a new pump but the same again so try another new filter, same again.

I lifted the pump out again to inspect and found this.

You can just about see the difference in fuel level between the rear of the tank and the baffle that the pump sits inside-see it? The tank sealer has sealed off the baffle housing which would not be a problem on a full tank but when the tank is near empty, it is and starves the pump.

Luckily I have an angled drill so with the aid of a shortened drill bit was able to drill several holes into the back side of the baffle housing.


That sorted it. cheers

    

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