Topic: 1/2" petcock for CB550 tank?

[jamesbekman]

Hi Everyone,

First off, I have a CB500 with what looks like a CB550 tank on it (looks like a cb500 tank besides the threaded petcock).  This bike also had cb550 marked pipes etc...

Anyways, I am in need of a petcock for the tank. 

My brother in law just took the tank to the hardware store to double check the thread size as I know there are different varying petcock sizes for CB550s.  The people at the hardware store said it is 1/2", not a size in milimeters.  Does this make any sense?

Regards,

James

[jamesbekman]

I just came across this link: http://www.dotheton.com/forum/index.php?topic=34066.0

The picture in the link looks exactly like the petcock that broke.

[goldarrow]

  The people at the hardware store said it is 1/2", not a size in milimeters.  Does this make any sense?

are you awae that this is a japanese bike? and they use metric system. 

may be post pic of your broken petcock so we can help better.   there are 1 or 2 outlets petcocks on these bikes, and couple of different design, in any combination.  specific year of the bike will also help....

[Bankerdanny]

Are you sure that your engine is a 500? Maybe somebody combined a 550 with good engine and a 500 frame with a title?

But like Goldarrow said, post pictures of the tank and petcock.

[jamesbekman]

I am fully aware Hondas are metric.  It is definitely a cb500.  I'll take some pictures. 

[ncstatecamp]

Actually, though it's a japanese bike thus metric, other threads could fit perfectly fine. I recently did a write up for the 20mm 1.5 750k threads, a 3/8 npt compression connectors threads beautifully.

I also found that it measured to a 5/8" compression cap, or .75" 18tpi thread

[Stev-o]

Actually, though it's a japanese bike thus metric, other threads could fit perfectly fine. I recently did a write up for the 20mm 1.5 750k threads, a 3/8 npt compression connectors threads beautifully.

I also found that it measured to a 5/8" compression cap, or .75" 18tpi thread

Now why would you do that??

[ncstatecamp]

For the life of me I could not find a petcock that would fit it.... But if you can find me a m20x1.5 petcock show me the way!

[Stev-o]

For the life of me I could not find a petcock that would fit it.... But if you can find me a m20x1.5 petcock show me the way!

Some can be hard to find.  Thought maybe you were a plumber and had the spare parts in the back of the van!
What bike?

[ncstatecamp]

Cb750k2. Not a plumber, went to lowes, fastenal, fergensons, local hardware etc finally came across that fitting.

[Stev-o]

Cb750k2. Not a plumber, went to lowes, fastenal, fergensons, local hardware etc finally came across that fitting.

This it?  (My K2 is in storage)


http://www.ebay.com/itm/1972-Honda-cb750k-cb-750-k-cb750-gas-fuel-petcock-valve-/130546714737?pt=Motorcycles_Parts_Accessories&hash=item1e6530c871&vxp=mtr

[goldarrow]

I think I have one or two of those around in my backyard shop. 

All you gotta do is just ask, brother.  And you'll have a nice petcock that would look great with your bike.....

[ncstatecamp]

No idea if that's the right one (no sizes listed), idk if my tank is an actual k2 or what and ive never personally had a petcock for it. I got the bike as a pile with an inoperable title.

[ncstatecamp]

I think I have one or two of those around in my backyard shop. 

All you gotta do is just ask, brother.  And you'll have a nice petcock that would look great with your bike.....

Ever find out if you had an extra petcock?

[goldarrow]

Sorry didn't realize you were looking for one.  I thought you had it all sorted out with your mod. 

Here are some on feebay, seem like good price too

http://item.mobileweb.ebay.com/viewitem?sbk=1&nav=SEARCH&itemId=300949956169

http://item.mobileweb.ebay.com/viewitem?sbk=1&nav=SEARCH&itemId=300950042449

[Scott S]

 I bet you have the '76 tank, which has a one year only petcock. I went through this same search a little over a year ago.
 Just about your only option is to pony up and buy a genuine Honda petcock, about $100 to your door.

http://www.ebay.com/itm/Honda-CB-550K-550F-550-F-K-CB550-NOS-petcock-1975-76-/300949108207?pt=Motorcycles_Parts_Accessories&hash=item4611f6f5ef&vxp=mtr

 You can sometimes find a CB750 model that will fit for a few bucks less, but it's a single outlet, so you'd need to buy a fuel T and then, guess what? You're right back at ~$100.

[ncstatecamp]

Sorry didn't realize you were looking for one.  I thought you had it all sorted out with your mod. 

Here are some on feebay, seem like good price too

http://item.mobileweb.ebay.com/viewitem?sbk=1&nav=SEARCH&itemId=300949956169

http://item.mobileweb.ebay.com/viewitem?sbk=1&nav=SEARCH&itemId=300950042449

I've got a spigot or threaded rod coming out of mine. Those bolt on....

[goldarrow]

may be this one you're looking for. single outlet, then just add a T to the fuel line

http://www.ebay.com/itm/1975-Honda-CB750-Four-CB-750-H694-fuel-petcock-/231010184090?pt=Motorcycles_Parts_Accessories&hash=item35c947ab9a&vxp=mtr#ht_1608wt_904

http://www.ebay.com/itm/1975-Honda-CB750-CB-750-H664-fuel-petcock-/290916669962?pt=Motorcycles_Parts_Accessories&hash=item43bbfc1a0a&vxp=mtr#ht_1537wt_1161

[goldarrow]

I bet you have the '76 tank, which has a one year only petcock. I went through this same search a little over a year ago.
 Just about your only option is to pony up and buy a genuine Honda petcock, about $100 to your door.

http://www.ebay.com/itm/Honda-CB-550K-550F-550-F-K-CB550-NOS-petcock-1975-76-/300949108207?pt=Motorcycles_Parts_Accessories&hash=item4611f6f5ef&vxp=mtr

 You can sometimes find a CB750 model that will fit for a few bucks less, but it's a single outlet, so you'd need to buy a fuel T and then, guess what? You're right back at ~$100.

very intersting, i wasn't aware that the dual outlets could be a pain to find them used.

[ncstatecamp]

It's not so much the dual spigot but the correct size nut, for those that are threaded on, not bolted. Most seem to be an m16 or m18. I have no idea what year used an m20....

[goldarrow]

The nut that goes between tank and petcock? That one is left hand thread.  I don't think you'll find that nut alone by itself without petcock

[ncstatecamp]

Golden, I dont need just the nut, I need the whole unit. What I was saying is the only ones I can find (whole unit- nut, spigot, tube, reserved, etc) are built for a m16 or m18 shaft. My tank uses a m20 shaft.