Pregnant fuel tank

[Dave.T]

Refer to "Newly Acquired RZ350"...

Picked up the bike today, and Fark.....
It seems that many moons ago, somebody has tried to repair the dents in the tank with compressed air...

The underside of the tank has tried to pop out and bulged, causing whole tank to expand....

I have access to high negative pressure vac pumps to try and reverse this 'pregnancy'

Anyone attempted this before????

Got a fair idea where to apply a bit of heat and the odd tap with a hammer to correct while under vacuum, but....any tips appreciated.

Dave

[Dave.T]

Bottom had bulged, thus pushing the bottom of the tank out by 50mm plus. Actually it was over 100mm at the centre.
Could not believe how easy it was to fix.
Connected vac pump to petrol cock and let it rip. Within seconds the sides started to return to where they should be. Repeated 4 or 5times allowing tank to go past where it should.
A couple more "suck downs while tapping the underside of tank and hey presto tank back to shape.
Didn't measure the pressure, no more than 500mbar at my guess.
If anyone has a tank with the same problem and doesn't have access to a vac pump, be happy to help out.

[JonW]

wow, well done!

[Dave.T]

Thanks for the compliment JonW.

Visited your 2smoked site many times prior to buying my 83 and gave me the inspiration to buy a RZ and relive my youth.

I had an 83 RZ with a John Gourlay built race motor when I was young bloke living in Tassie.
Was one fast bike.

The 83 I own is close to seeing the road again, just needing paint and final re-assembly. Purchased the R1 caliper brackets from Norman Surgeon and can't wait to pop some eyeballs with what an old bike can do.

You obviously have heaps of experience with these old girls. Any advise for modifying standard forks.

[JonW]

Thanks for the kind words.

Ahh the 83 forks are not great but there is help, better springs and oil will help and you can fit the valves from mikesXSs for about US$50 as well, but its not a straight or simple swap for many, depends on what you have access to engineering wise.

[Dave.T]

Shouldn't be much if an issue.

Have a few toys to play with. Haven't got the CNC miller yet though.

There's not a lot I can't do myself or go to mates
house, drink piss while playing in the workshop.

Appreciate Do's and Dont's comments.
I want to set the suspension up nicely without going stupid on cost, but want to make use of the serious brakes upfront to operate as best as possible with standard 'looking" front end.