Topic: PIC Request

[Harsh]

I can't find any pics of the underside of a tank.  I have a '74 CB750 that I am not sure if everything is there and what is there if it is correct.  In particular I am looking for the petcock area, any hoses/tubes that go in to/out of the tank, and the tabs along the outside edge.  I am really starting to think some real shady stuff was performed by a PO.

This is what the PO thought was a good fuel line.

[ekpent]

I don't have pics available but that fuel line could be classified as 'excessive' for sure  There are two holes through the carb backing plates that the line goes through if its pre K5 and the 75-76 has one line and a splitter.

[Harsh]

Well after I got home today I stripped the paint and bondo (yes they bondo'd around it to make it look pretty) around the plug and this is what I found.  I am going to go out on a limb and say this isn't the way it is supposed to be.  The problem I run into is that I have seen two different styles of petcocks out there.  One looks to be held on with two screws and the other with a single nut.

Is my tank toast?  Is it possible to still use a real petcock?  Looking inside I don't see the plastic/brass tube.  I am not sure how to proceed here so any and all help would be appreciated.

The black and brass plugs are mine.  I inserted them so I could add some MEK to strip a failed Kreem liner.

[nancy]

That's a big NOT. The petcock screws into underside of tank...nothing welded or bonded to the tank - just holes for fuel to fall from..into the petcock.

[Harsh]

So I guess it is safe to assume I am kind of screwed here.  It is hard to see inside, but I am willing to bet that the screws were snapped off hence the welding.  The flat part isn't very flat anymore do to the horrible grinding that was done so I guess using an oem style petcock is out of the question.  Any thoughts on how to proceed?

[Greggo]

They may have threaded it for a common Harley 3/4" type.  They're $10 on fleabay if that's what it is.

[Harsh]

They may have threaded it for a common Harley 3/4" type.  They're $10 on fleabay if that's what it is.

Thanks, I will give that a look, but  not sure if 3/4" will work since the head on the brass piece I inserted is 9/32".  Maybe they have a 1/2" Harley type.

[nomad]

Are you ever down in the Raleigh/ Durham/ Chapel Hill, NC area?  If so, I have a tank off of a '74 750 you can have for free.

BUT, it had a nasty, horribly done Kreem job in it.  I tried to remove it and found that the PO had just Kreemed over a lot of existing rust.  After screwing with cleaning it up, I said to hell with it and just got another tank.  This one looks nasty, but could be cleaned up and restored if someone wanted to put the time into it.  It'll need the rest of the Kreem cleaned out, and the rust removed before you paint it, which it'll need that too.  A radiator shop could get all that out and coat it for you.  On a positive note, it doesn't have any dings in it... I guess that's something.

PM me if you think you might want it and can get down this way.  Or if you want it and can find someone from this area you trust to bring it to you.  If you don't want to mess with it, I totally understand and it won't hurt my feelings at all if you don't want it.

[Toxic]

You are not screwed, my bet is on the Harley petcock fitting.  Measure it and see what you have then call Pingle Fuel Taps, they will have what you need.
Their taps are incredible but pricey.

Besides the liner how is the rest of the tank?

If you go with Nomads free tank it would be worth it to spend a couple of bucks to have a rad shop remove the liner

[Hinomaru]

Here's what the 69-74 two screw petcock style tank underside looks like and is correct for your 1974 CB750: 

(click on image for a larger view)
 

[Harsh]

You are not screwed, my bet is on the Harley petcock fitting.  Measure it and see what you have then call Pingle Fuel Taps, they will have what you need.
Their taps are incredible but pricey.

Besides the liner how is the rest of the tank?

If you go with Nomads free tank it would be worth it to spend a couple of bucks to have a rad shop remove the liner

My tank has a number of dents and dings.  I haven't stripped the paint off the entire tank, but there looks to be some Bondo'd areas and I am pretty sure there is a leak somewhere.

I looked up the Pingle stuff and you weren't kidding about being pricey


Thanks for the pic Hinomaru.  That adds a lot of clarity to what I am picturing.  Plus I see what the tabs are supposed to do.  They hold on the chrome trim ring.  I won't be using that part, but it is nice to see what that are supposed to look like.  Mine are folded flat back on themselves and half are snapped off.




Nomad...I sent you a PM.

[seanbarney41]

Z1 Enterprises sells petcocks that mount, function and even look similar to Pingel at a very reasonable price.  They also sell universal diy adapters to mount them.  I'm not sure if these can easily work in your situation but you might want to check it out.

[MCRider]

Hinomaru has it right as usual for the 74 and earlier tanks. The 75 and later has a bung and the petcock has the single large nut. They moved it to the left side as well.

So if you have a left side (can't tell in your pic) bung mount you have a 75 or later tank. Gotta admit your bung doesn't appear factory.

I took my trim tabs off as well. I'll use automotive door edge guard which is adhesive backed in colors.

[Harsh]

Thanks for all of the replies, info, and offer.  This is with out a doubt one of the most helpful forums I have ever been a member of.  I will give Z1 a look and see what they have as well, but for right now I am going to take Nomad up on his offer.

[josephus]

Somebody really botched that tank up! inside should be a thin piece of metal friction welded in place thats threaded for two screws if not its a screw on nut bong.

[Harsh]

Somebody really botched that tank up! inside should be a thin piece of metal friction welded in place thats threaded for two screws if not its a screw on nut bong.

Looking inside the tank that piece is still there.  The nuts for the screws are still there and do not look to have a broken screw in them.  At this point I believe that someone just welded on a bung because they were to cheap or lazy to go buy a petcock and wanted to use what they had laying around.  Knowing the guy that I got the bike from it wouldn't surprise me if he did it.

[josephus]

good possibility