I made a 200 klick pilgrimage trip to the city of Sandviken today.
Sandviken is the home town of the Swedish company Sandvik, makers of Sanvik Coromant. Probably known to a lot of you, and for those of you that hasn’t set foot in at metalwork, Sandvik is renowned for being ”tha shit” in metalworking cutting technologies.
Once there I found this neglected little thing, almost original Gpz750A1 -83.
80.000 km on the meter, all parts intact (except exhaust) all the know problem, sweating oil around the cylinder head gasket, small crack in one side panel and the main fairing, running foul when cold. Just what you expect of a bike 30 years old.
Who was I to look away from this poor thing that has been sitting on the Swedish equivalent of Craigslist since 16 Aug?
In need of carburetor love and probably new valve seals, something that can be taken care of when changing the head gasket. Best of all, it doesn’t have to happened this winter, so if I don’t finish my 82 R1 by spring, I have a backup.
I paid 800 USD for here custody, which was probably 100 USD too much, but what a heck.
So those of you, who drove these bikes when they were new, probably get it when I say I am working on my New Gold Dream
She is your friend until the ocean breaks
And when you dream, dream in the dream with me
81 - 82 - 83 – 84
New Gold Dream
All loaded up and on the way to her home.
Wonder what will become of her when she grows up? a WRR?
Starting working on my own harem, 82 and 83 down, two more to go!
After a long winter were I have neglected my last find in the garage, it was time to get the lady up and running for the season as I still hadn’t driven her yet.
Set valves, strip down carbs, rip out all gong-hoo cabling PO had added, new plugs, new battery and she fired up right away.
Shut here off in order to gear up. Ouuups fuel flowing from nr 1#, dammit, of with the carbs again. Wipe off float needles and seat again, clear tube test, carbs on.
Fire up, take off and she run like a charm in a need of a carb sync. Unfortunately I don’t have my old clocks around anymore so it has to wait until I get a chance borrow a pair.
Happily I rode all week when I figured out why the brakes were so scary! Leaking fork fouling the disks, so that saved last Friday, fitting new fork seals and dust covers and cleaning out all the goo that had taken up, refuge in the lower part of fork.
When that was done I started to count up the little things that needs to be fixed and ordered , head gasket will need an overhaul as the oil gallery O-rings are on their last lap. Will try retighten the head hoping I can wait with the gasket change as there is need to change the valve seals, exhaust fumes are clear.
But my dreams where shattered the other day as the carbs started to over flow again, petcock don’t shut, obviously rust and stuff in the tank getting the best of the petcock and the carbs. Had been trying to pick up a fuel filter during the week, but gas stations only sell hotdogs, groceries and mocha latte frapposhinos or what the F@#@ they are called these days I hadn’t managed to get one on.
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Any how I set of this weekend to clean the tank and thought I try to etch it out with vinegar. Living in an apartment building and being limited to work on the balcony didn’t give me the options to play with the beefier stuff.
Cleaning out went well, added a couple hands full of gravel and a good two liters off vinegar shook around for a while and finally toped it up as full as I could get it. Every time I have passed it I have given it a shake and turned it around.
After 48h I opened it up much to my disappointment it didn’t work out well, it is impossible to soak every part of the tank inside and the parts that are exposed flash rust right away.
So I have to come up with another way to derust. . . . . .
Hold on,hold on. Dont give up on the vinegar yet. I promise you it works. Dont know what youre using but you need brown vinegar.You also need to let it soak. I left mine for 2 weeks.It came out great.
Fill it up to the brim with vinegar.Let it sit for a couple of weeks,drain it and rinse it out with soda. Wash it out with water and let it dry.I did mine in the summer and it was dry after half an hour in the sun. You could also put it in the airing cupboard.A misting with some WD40,to kill the flash rust .Bobs youre uncle and Fannys your aunt
Davido I did a tank with Kreem and a few with HCL when I was a kid and it was quick and easy, but back then I had my parents garage to do my experiments in, a totally different ball park than living in an apartment and keeping the bike in the communal garage. I also guess that I by age do care a bit more about the nature as well. . . . . . .
I googled the living daylight out of the Vinegar etch and if I had known that I takes two weeks I had probably not given it a go now when the season has stared. But what bugs me the most is that it would require an open 50 Liter vinegar tank, in which I can entirely submerge the KZ tank in to.
Don’t see that happening on my balcony any time soon, that would probably require a quick Sheela swap.
I will probably have to fix the tank on my other bike to this fall, then I will give it another go with Vinegar, but I still don’t see the difference between White and Red/Brown. Its roughly 6% acetic acid (CH3COOH ) one way or the other.
So you guys don’t think it’s a good idea to prop some media in the tank, wrap it in a blanket and fixate it in a mixer and let it tumble for an hour?
Anyhow now I got an extra 5L of White Wine Vinegar,
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good enough to make approx. 1000 servings of Béarnaise sauce, all I need is a good 25Kg of butter a few eggs, white pepper and a tropical forest of tarragon.
Davido! I know my aunt’s got a fanny, but who’s that Bob dude?
I think Vinegar is pretty eco friendly compared to the other options. I wouldnt submerge the tank in vinegar,unless you want to strip the paint.Just fill it up. The stones/screws/nuts and bolts in a cement mixer seems a bit brutal. More suitable for removing heavy rusting.Dont know how bad yours is. I tried nuts and bolts with the tank strapped to a length of wood in a drill.Nearly took my head off and it was a bugger to get all the nuts and bolts out.
I know others have used a similar method with success,I can only speak of my own experience.
No disrespect to your aunts fanny.Or your uncles bob. Nice link GPzMOD750.
I remember a few on here wrapping one in a blanket and running it in a clothes dryer but make sure the blanket is sealed up very well and thick ..... I'd be worried about it getting banged up.
1978 KZ650 b-2
700cc Wiseco kit 10 to 1.
1980 KZ750 cam, ape springs, stock clutch/ Barnett springs.
Vance and Hines Header w/ comp baffle and Ape pods, Dyna S and green coils, copper wires.
29MM smooth bores W/ 17.5 pilots, 0-6s and 117.5 main
16/42 gearing X ring chain and alum rear JT sprocket....
If you have limited room on your balcony and want to remain eco-friendly in rust removal of your fuel tank; why not try electrolysis?
My KZombie has a pretty nasty tank and this is the method I was going to try.
Your time will depend on your tank's rust situation but the materials investment is cheap assuming you have motorcycle battery and a battery charger or battery tender.
Here's a video demonstrating it, however, this example does not use the battery, just the battery charger. Some chargers won't work and need you to connect your battery in parallel to the tank and anode (basically charger's positive to battery (+) then to sacrificial anode and charger's negative to battery (-) then to tank steel.
Check it out:
I'll be doing this myself, as I said on KZombie's big old rusty tank this summer.
Ok @Wrenchmonkey you convinced me, I will try the Sodium Carbonate electrolysis method.
Went to the hardware store and picked up laaarge under bed storage box that the tank can sit in, so that I will not be spilling Sodium wash on the neighbor below. Sodium carbonate and a roll of iron fixing iron wire and I will be all set up to getting going tomorrow.
Isn’t an irony that when I bought the new battery the other week, I bought a new “smart” charger and tossed my old “stupid” charger in the bin. Thinking why shall I keep this!
Looking forward to see if this will cure it.
@Steve I have picked up some fuel filter, but as the petcock got jammed there I thought better trying to fix it up as I ordered a refurbish kit for the petcock. Thinking there is no use in buying new stuff and then sending a known problem in to it.
The electrolysis method works like a charm. I rescued my XS650 tank that I was sure was a goner. Looks brand new inside.
After the electrolysis I used a rust remover (evapo rust? ) and let it soak for a day.
2016 Yamaha FJR1300ES
1982 GPz750 R1
1974 Kawasaki H1
1976 Kawasaki KZ400
1979 Yamaha XS650 cafe'
2001 Yamaha YZ426
1981 Honda XR200 stroked in an '89 CR125 chassis
1967 Triumph GT6
"If you didn't build it, it's not really yours"
It really works but it took about a week until the tank was clean and of course I learned stuff on the way.
1. Duct tape is not sufficient to keep the fluid in the tank. One need to fabricate washers to cover the petcock and fuel level indicator openings with. Next time I will use an old nylon cutting board to close to openings with.
2. You need to fabricate at least two offer anodes that you can switch between. I made mine of spray can tops, 3mm iron wire that insulated with crimp tube at the top, so it didn’t short against the filler hole.
3. The shape of a ZX750A tank requires that you flip the tank upside down at the end in order to get the rust that will build up at the top as it’s practically impossible to fill the tank to 100% and whatever that is not covered with the electrolyte will rust like an Italian car.
So if you suffer from a rusted tank, this is the way to go, cheaper and faster than vinegar. Hell of a lot cheaper than phosphoric acid (but slower) and absolutely harmlessly compared with hydrochloric acid (fastest and not suitable for a balcony derusting).
After I got the tank back on the bike it’s only been misery for the last two weeks. Nessism is in many ways right, opening up a 33 year old bike without having all consumable parts at hand is STUPID!
I renovated my petcock as it was leaking, not having a new o-ring and nylon washers fitting it back to the tank was a bad idea . . . . . . . . . . two weeks fuel dripping from the tank . . .
Not having ALL o-rings and new float needles for the carbs, meant major fuel overflow filling the intake manifold with fuel and spilling fuel everywhere making Exon Valdez look like little league, do I need to say at the least suitable time . . . . . twice . . . .
It really gave me the shits as I was worried I would fill the crank case and run down a perfectly good stock engine.
But finally today.
All tank gaskets changed, all carb o-rings swapped, new float needles, needles seats polished with the help of ear-tops and ceramic stove top cleaner, float levels set, oil and filter change and it runs without leaving fuel trails.
I bought the bike to have as a runner this summer and so far it has not really delivered, I sincerely hope that the sweeting head gasket will do with a re-torque keeping its shit together this summer so I can ride and then rebuild the head when winter comes.
After work today I set out to see if I have my overflowing carbs and leaking petcock under control, so I set of to my buddy Erik for a 2xGpz 750 tour.
We had a fab time sweeping through the country roads of Roslagen and stopped for a burger at Östanå 59°32’54 N 18°34’28 E
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Petcock? Check! It still flow about 4 cl after the vacuum is gone but then it’s shut.
Carbs didn’t overflow and petcock seal doesn’t smell of gas, check!
But I am suffering from an oil leak on the front of the engine, I was just about to order a new heads gasket when I saw that the oil cooler hoses are soaked as well. If it is the head gasket sweating, there is no way that oil should reach the hoses when driving and to the point that they get soaked?
Guys what are your take? Sound like a sweet idea to press on new hoses before lifting the head?