1977 Honda CB750 Cafe Racer

[std]

I don't know about what pressure to use. It would be new territory to me too. I'd start out low, 30-40lbs.
Gas tanks aren't really designed for pressure.

I'm sure someone that has done this will turn up.

[DanStokes]

When I was at the EPA, we had to drain fuel tanks, and a drain valve was provided for this purpose. Every once in a while, someone would forget to remove the gas cap before draining, and we'd implode a tank. We had an N2 bottle sitting there with a regulator, and we'd start at zero pressure and turn it up until the tank popped back to full size. It rarely took more than a few PSI. Of course, those were car tanks and were much thinner. Bottom line - I'd just kind of creep up on it and see what happens. I wouldn't exceed like 25 or 30 lbs. That's a TREMENDOUS amount of potential energy (pounds per square inch X # of square inches), and I sure don't want to see you get hurt. Unless you are POSITIVE that the tank is without ANY fumes, I wouldn't add torch heat. Residual vapors can happily kill you.

If all else fails, call Andy Schauffer in Austin, TX. He runs a used motorcycle shop, and he has more than 100 (I'd guess) motorcycle tanks hanging from the ceiling - all different makes. He harvests them from crashed or otherwise trashed bikes that come his way, and he saves the good ones. I may have mentioned Andy on this thread before. Anyhow, he's likely to have something for you. Worth a try. If you can't find a number for him, I'll get it from my bro, who is a friend of Andy's.

Later
Dan

[Matt Cramer]

Cool project! I like old Japanese bikes myself - my first bike was a '79 Honda CX500, and I might get another '70s bike sometime this year if I can find the right project at the right time.

[JustinSuhas]

Matt and i Farted around on the bike for a little bit today. Mostly drank beer and stared at the latest purchase

We took off the old seat and handlebars and set our new ones in place. I see the potential.






We werent a big fan of the exhaust can on it now, but we like the 4-1 pipe setup. Upon further inspection, there was quite a bit of rust on the muffler. Im going to try and pull of the old muffler and find another that is better looking and sounding (this one sounds great, just too quiet) here's the rust

[dulcich]

Its idiotic to think that you can "pop" that dent out with compressed air. You need to clean the tank out and use a stud welder to pull the dent if you want to fix it. Seems to me you are buying all kinds of junk bikes you don't really need thinking you are making progress when you should be working on the actual project - a common trap.
-Dulcich

[JustinSuhas]

Its idiotic to think that you can "pop" that dent out with compressed air. You need to clean the tank out and use a stud welder to pull the dent if you want to fix it. Seems to me you are buying all kinds of junk bikes you don't really need thinking you are making progress when you should be working on the actual project - a common trap.
-Dulcich

You bring up a valid point about spending time working on the project, we need to do more of it. but, until very recently, we have just had a wad of parts, nothing to connect with. Now we have a full bike, just the fuel this project needed. Rest assured, the flogging will commence, soon.

I appreciate your input (thats what she said) but idiotic and junk bikes? ...c'mon man, this aint the Mopar Forum.

Ps. My dad was part of the team at Sherwin that tested the primer you laid on your vette.

[dulcich]

Just being a hard-ass, hope you don't mind the tough love; what you've got going in the earlier posts looks like a good project, just keep your eye on the ball.
-dulcich

[DanStokes]

Steve -
I wasn't guaranteeing success with the compressed air trick, just saying it's worth a shot. It's free and only takes a minute. If it works, cool, if not, back to plan B.

Dan

[ford141]

I have done the compressed air trick on bike fuel tanks, and yes it does work. Just watch how much pressure you put in, since the tank will have a tendency to "expand" away from the frame rails and then your lower front mounts won't line up. I wouldn't go over 30psi max.

[KeithTurk]

Dulich is right... it's a stud welder job... ( that's the closest Steve's ever been to both being right and having knowledge of stud services )

it is easy to get lost in projects... but you two yahoo's seem to be going down a common path.. Hows the math?

K