Can you not get a dentists mirror in the filler hole to see the back ?

My guess is they are pressed in from the back, but it is a guess. If they are, knock old one through and catch it, long bolt, push through hole, fit nut and pull in using a nut on the outside.

And do be careful, there's nothing more dangerous than an empty tank.

 

I can even see the nuts without a mirror. Unfortunately, they are pressed in a blind small plastic lug (hope I am clear, sorry for my English) from the outside when the tank was still hot in the press mould
The nut has and odd square shape with slightly rounded corners, that's why they overtwisted.
I can make and post the photo

 

 

Now I see. Well THIS COULD BE DANGEROUS but what comes to mind is soldering iron. Heat nut up until plastic softens then by some means pull it out - ling nosed pliers, also heated ?????

Once out find similar nut, maybe grind it round and epoxy in.

Might work ! Try not to blow yourself up though.

 

Heating the nut with soldering iron?
Good idea! Didn't think about it. Thank you
I will leave the tank without the fuel tap and with open cap for several days, hope the petrol vapour will evaporate

 

The old way to weld metal tanks was to fill them with sand, leaving no room for the petrol vapours, which are what causes the explosions apparently :big grin:

 

:big grin:
Yep, it's better to spend an hour by washing the tank out of sand, than sit with scorched face near the shapeless rest of the tank :big grin:

 

Scorched face would be good, but much more likely no head if it does blow.

You've done well to drill it and till be typing !

You could do it by drilling. 1mm drill, just keep drilling all the way round the nut, wriggle drill to join holes. Keep fitting new drills as you snap them

 

Tank Repair

Best way to stop the tank exploding when welding !

Stick the filler cap over the exhaust of a running car for awhile, of course make sure it is empty first.

Have done this a few times a long time ago and it does work.

Disclaimer if I see a bright glow this evening from the East it was not my idea to do this!:naughty:

 

I prefer using water in the tank when welding a tank. But drilling heads of bolts could give a spark so that would worry me enough. I have had my surprises with petrol and welding so I am very careful. Luckily plastic tanks don't need to be welded.

Ton

 

Frankly speaking, I drilled the bolts out without filling the tank with water or sand Immediately after pouring all petrol out, indeed
I didn't expect to have a spark by cooling and lubricating the drill with WD-40 without a pause

hilldweller: "You could do it by drilling. 1mm drill, just keep drilling all the way round the nut, wriggle drill to join holes" .
Thank you, sir, it should work!

 

hilldweller: "You could do it by drilling. 1mm drill, just keep drilling all the way round the nut, wriggle drill to join holes" .
Thank you, sir, it should work!

One chance of failure, if it was cast in and has a flange on the bottom to stop it pulling out.

Another thought, if you use 2mm and drill 300 degrees round leaving that thin area next to the filler hole then try and lever the nut away from hole. That leaves a datum face to help position the new nut.

 

Agree with Ton, I recall from Motorcycle/Car mechanics mags 60/70's, that a safe way to weld metal petrol tanks was to fill with water (after draining petrol) so no petrol vapour to ignite. You don't need a spark to ignite petrol vapour, heat can do it, but as you proved, drilling brass/plastic with wd40 should keep sparks at bay and cool drill bit. Isn't this forum great for advice! :big grin:

 

It is a real pity I am not a dentist
Yep, it could be good for F650 96-99. On those bikes you should unscrew all the bolts every time you take out the plastic and tank.
Maybe there is a more simple way?uzzled:
What if I drill the nuts through and install M6 long bolt to screw plain nut from the inside of the tank?

I am still reflecting on it, there is no hurry, have the time till the end of a March

 

What if I drill the nuts through and install M6 long bolt to screw plain nut from the inside of the tank?
I am still reflecting on it, there is no hurry, have the time till the end of a March

Is there no biking in Moscow over the winter ? We've no idea what a Moscow winter must be like to live with.

M6 sounds on the big side. If you manage to drill the nut then just epoxy the right sized on back in. Chances are the drill will grab the insert and spin it out anyway.

The part that could help a lot is Threaded Pillar. Basically a long nut. A good substitute for a proper insert. I've even soft soldered a couple of nuts together in the past.

 

Usually the winter in Moscow is rather severe. It is 0 - +2 now, snow and rain sometimes. But in the beginning of December the temperature changes to -10 - -15, -20 at night, it snows heavily, ice on the road . It is really freezing cold and the humidity is 100 %. This weather lasts till the end of a March. Some guys ride off road on the snow but it is nearly impossible to ride in town. I was told English winter is rather mild and you can ride during the winter.

Threaded Pillar what's that? A nut with a thread inside and outside, sort of the sump plug repair kit nut?

Unfotunately it is impossible to drill and pull out the nut, they are sitting very tight in the body of the tank. I tried to drill the rests of the stainless bolts from the nut and it began to spin but I didn't manage to pull it out . The other one also sits very tight. Chances to spoil the plastic around the nut. It is so close to the rim where the seal should be.

So, to my opinion, the only way is to change all the stuff a bit. Leave the nuts as they are, fill them with epoxy, bolt on alu housing to 4 existing nut, and drill M5 or maybe M6 holes between the former holes of the nuts. 3 new bolts with the nut and the washer inside will substitute 2 former brass nut. I hope so

 

the temperature changes to -10 - -15, -20 at night, it snows heavily, ice on the road

So, to my opinion, the only way is to change all the stuff a bit. Leave the nuts as they are, fill them with epoxy, bolt on alu housing to 4 existing nut, and drill M5 or maybe M6 holes between the former holes of the nuts. 3 new bolts with the nut and the washer inside will substitute 2 former brass nut. I hope so

Threaded pillar - see ebay 130579785658 as a guide.

That does not sound like biking weather. Yes, in England we can ride for 50 weeks of the year. Scotland get more snow but the main roads will usually be clear 50 weeks. We sometimes get a really bad snow fall and the we can't cope because we just don't have the cash to keep enough men and equipment on standby.

I don't like the idea of nuts inside because I'd be sure to drop them but it is a simple solution. Use locknuts ( I'm sure you would ).

Isn't the internet wonderful, someone in England helping someone in Russia to repair a German bike. Isn't freedom wonderful, we were all supposedly enemies not that long ago but in reality it is never the people who are enemies, especially not bikers. Just out of interest I asked Google Maps the route from Calais and it did it in a few seconds coming up with 1760 miles. That would be one hell of a ride

 

Russia and England were also allies not only enemies not long ago. It's just politics, it cannot influence on relationship of people, who want to communicate, be friends, help each other.
My friend Tony (Tony P here) made a ride on his F650GS Dakar from London to Novosibirsk. He was surprised when he found out that the distance between London and Moscow is nearly the same as between Moscow and Novosibirsk

 

I remember him writing about that trip. And he was still only half way across Russia, what a country. What a difference to the UK, from east cost to west is as little as 70 miles roughly where Hadrian built his wall. Our longest run from Lands End to J O'groats is only 837 miles. Nice and manageable for bikers.

 

I might be wrong but a soldering iron isn't hot enough to ignite petrol vapor, I think about 200 degrees.A spark from a flint is about 1000 degrees...Warning...I might be talking botox.....Tosh

 

I set mine at 300 degrees. Way above the melting point of solder but it heats the join that much quicker. But the worry is static, metal to metal contact, sort of "Are you fellin' lucky punk ?"

He obviously is lucky, he keeps surviving drilling it. Think of the sparks in a drill motor. Oooooooooooooherrrrrrrrrr.

 

HI i am from south Africa not a clever guy but Wat if you drill the stainless out re thread the hole and insert a helicoil if you are scared of fire ore explosion just fill the tank with CO2 from a CO2 fire extinguisher.