Cleaning of fuel tank.

If you have read the post towards the beginning of this blog you will have seen how bad the carbs were gummed up after years of standing with unleaded fuel in them.
Well the fuel tap and tank were just the same...
Just removing the fuel filler cap was an effort as it had rusted in place pretty tight, but after squirting plenty of WD40 around it and gently tapping it with a plastic hammer I was able to persuade it to unscrew. Removing the fuel tap also revealed the gum in the bottom of the tank that was like pulling soft toffee apart.
So having seen all this I knew I had some serious cleaning to do and looked on-line to see what was available. Frost Auto restoration had the POR-15 fuel tank cleaning and sealing system which I thought would be just the job so purchased a kit. I had read somewhere else that to clean flaking rust from the inside of your fuel tank, you should put stones in the tank with a  cleaning solution and shake it thoroughly.
I first mixed up a solution of the POR-15 Marine clean and swished that around the tank, before draining it out to help loosen some of that gum.
I then mixed up another lot of the same solution and this time placed 100 carefully selected stones from my driveway, ensuring each one had nice sharp edges to get any flaking rust or old fuel tank sealer off. Another vigorous shaking session, followed by 20 minute rests in between each one, (this rest was mainly for me, not the solution to do its work)! I then left it over night and proceeded with more shaking the next morning before draining and rinsing the solution out of the tank. It was certainly looking much cleaner now.
Now before putting in the next solution, which was a POR-15 Metal Prep I had to remove the stones. I already knew that these stones were to big to come out of the fuel tap hole but thought it would be easy enough to tip the tank upside down and get them out of the filler hole, the way they went in. But that was not that easy. I turned the tank over, shook it all about but not one single stone came out! Oh, bummer I thought, that was not how I planned it. So I went over to my tool box to get my long claw tool and proceeded to go fishing for stones. This again wasn't as easy as I had thought, resulting in only one stone every 4 or 5 grabs, ( I never was any good at fishing, I used to go with my brother, sitting only 20 feet from him on the same river bank and he would be there pulling fish out and every time  I reeled in I just had a tangled mess. I even tried casting into his swim, much to his annoyance, but still didn't get many fish, so this task was going to be a challenge right from the start) but eventually I got all 100 back out!
I then proceeded to using the metal prep solution as instructed and carefully dried the inside of the tank out ready for the sealer.
However, it was at this point that I decided to do some more re-search into sealers as I had been warned that sometimes they can cause other problems. Googling this informed me that the POR-15 sealer was actually OK as it was OK to use with modern fuels that contain ethanol additives.
But what this extra research also told me, was that it was best to remove the old fuel tank sealer, (the matt red finish in BMW tanks), before applying the new sealer. To do this you need to user POR-15 Por-Strip, a powerful paint stripper. The problem with this is that I did not want to re-paint the outside of the fuel tank so in the end I decided not to use the sealer coat as it was not as though I had any leaks from badly rusting parts of the tank. The whole purpose of the clean was just to remove the old sludge and gum which the process so far had done very nicely.


So the tank is clean, now I just have to clean up the old fuel tap and replace the seals within it. It looked like  a simple enough job, but things didn't turn out  how I expected!
I had borrowed a small ultrasonic cleaning tank from a friend, I then used a solution of water and white vinegar, put the tap assembly into this and started it going giving it 2 15 minute sessions, it looked OK but I thought it would be best left in the solution over night before dis-assembling it the next day. I came to get it out the next morning and to my horror, part of the alloy body had just corroded away I  the solution meaning that this fuel tap was toast, oops! Oh, well I will order a new  fuel tap and take this opportunity to get one with a horizontal outlet which I think will make the fuel pipe routing better.

Where did the time go?

I started this project back in November last year with the aim of getting the bike on the road for the HUBBUK event as I thought this would be a fitting place to take the new steed. Back then I thought 7 months would be ample time to get the bike ready, not a complete re-build, just a strip down and clean up, change the oils etc. and get it ready for it's MOT.


Well, it is now the beginning of May and I realise that there is plenty to do yet as I have spent far too much time on the front end, and still have a lot of other work to do before the 19th of June!


So I turn my attention to the rear end of the bike and proceed with removing the rear racks, mud guard and wheel. Now that gives me better access to cleaning the rear subframe and exhaust silencer, which the chrome is in fact far worse than the handlebars were but with my part worn scourer sponge and more Autosol, I get stuck into cleaning it up and the end results lifts my spirits to press on and polish the framework with more of the black dyed polish with more amazing results!
As the inside of the rear final/bevel drive unit was free from oil, just brake dust, I decided  not to replace any of the seals at this stage and carry one as I have done with the engine in just cleaning it all up so I can check for leaks after running the bikes for a bit. The rear brake shoes were cleaned and out back on, a new tyre fitted and wheel back on making the bike look more complete again.

Been a while...

It has been a while since my last blog post and although I haven't spent as much time on the old bike as I would have liked, I have been busy some work on it...

So after the excitement of getting the engine running, I think about what the next job should be.

Finally I decide on cleaning the front end up, and I start by looking at the handlebars which have a light layer of rust over them due to being stored for all those years in a garage. I soon realise that this would be easier if I removed the bars, so with no further ado, I start by removing the instrument surround/handlebar pad which was easy as eating cake. Then I look at removing the switch gear, levers etc. It wasn’t long before these were off too, but hey where did those wedge shape things fall from? Oh, well, I will sort that out later! So now just to remove the handlebar clamps and he presto I have the bars in my hand. Staright away I reach for the Autosol chrome cleaner and a part worn scourer sponge to help me get the pitted rust spots cleaned up and before long the bars looked like new. Wow, the quality of the chrome on these old BMW’s is great.

Great I thought, I will look at putting the bars back on, but the top plate is looking rather rusty too, so it wasn’t long before I had stripped the entire front end down leaving just the bottom yoke in place.

Over to the sand blaster to clean up the top plate, handlebar clamps, instrument/headlamp bracket ready for a fresh coat of satin black paint. Whilst the paint on that lot was drying/hardening, as I like to leave freshly painted items several days before re-fitting, I turned my attention to the forks that I had removed. After draining the fork oil, which incidentally I found more oil in one leg that the other! I then cleaned the lower alloy finished legs trying several different chemical cleaners and after some scrubbing and rinsing they looked pretty good.

Then I thought, whilst I am this far, it would make sense to check the head bearings for sufficient grease, which were absolutely fine but I re-greased them with fresh grease anyway. With the bottom yoke off it also made cleaning the headstock area of the frame easier, which then lead me into polishing the entire frame with a black dyed polish so that you don’t see any white area of dried polish anywhere. As I done this I removed all the electrics from the top of the frame and cleaned the terminals and applied some ACF50 to them for good measure.

So now another few weeks have passed of more cleaning and polishing of front end bits, I decide enough is enough and re-assembled the front end, just leaving the front brake system to sort out another day, but with a new front tyre it all looked rather good.

Engine running...

Woo-hoo, got the engine running :-)
That is the first time it has run in years!


It ran a bit rough to start with, mainly due to the amount of oil I put down the bores, so the plugs oiled up and had to be cleaned a couple of times. It also blew some rust out of the exhaust system covering everything in its path.
So now going to change the oil and filter again as I initially run it with flushing oil, then run it some more.

Clean carbs...

The carburettors have now been re-built and mounted back on the bike. That's a major step forward to getting the engine running which I hope to do soon.

 

Here is a picture showing the before and after pictures of the carbs...

 

 

 

 

Dirty carbs, outside and in...

One of the first jobs to do in order to get this bike running is remove the carburettors and strip them down.

Once removed I gave the outsides a bit of a clean before dismantling them. This itself was quite a job but after a few hours they looked much better, although I new it was only part of the job as the most important part, the insides, was yet to be done.

So on with the strip down and I started with the right carb which went well, with all the parts carefully put aside ready for further cleaning.
But then came the left carb, which proved to be a lot worse than the right carb. After removing the float pin and float I was surprised to find that the float valve did not fall out like the right one did and as you would expect. No, instead this was all gummed up, (due to 11 years standing with the old fuel in the carbs) and even after soaking in fresh petrol and blowing down the inlet with a blow gun, it did not want to move. Eventually I won the battle with the help of a pair of pliers and brute force, which then necessitated a new valve but that was alright as I would have replaced it any way.

With the float valve out, the fuel inlet was still blocked and was proving very stubborn to clear properly. So after ordering the carb re-build kit plus a few extra bits, I boxed all my carburettor parts up and took the to Wheelfit Motorcycles near Cambridge, where they put them in their ultrasonic cleaner for a few hours. They came back looking great, but my normal paid work got very busy so the rebuild was delayed until the Christmas holidays.

Motorcycle Live show...

I went to the Motorcycle Live show at the NEC, Birmingham today, and met a fantastic chap, Sam Manicom on the Overland Magazine stand, who was a delight to talk to and gave me inspiration to travel far and wide on my ST when it is all re-built.

Check out his website, http://www.sam-manicom.com/ and see the amazing journey's he has had on his BMW R80GS.