Topic: CB550 petcock kit?

[Scott S]

 I have a '75-76-ish tank on my Sweep The Floor bike. It has the petcock that threads onto the tank.
 Bought a gasket for it, the round, rubber disc with four holes, only to find out that's the wrong part. This petcock has a cone inside that flips back and forth between on/off/reserve.

 Are there kits available for this type petcock?

 What are the threads? I see some listed for the CB twins that look like what I need (thread on, dual outlets, etc.), but I'm not sure if they'll fit my tank. They're listed as 16mm x 1.5 thread.
 If it fits the CB500 twin tank, will it fit my 550 tanks?

[bryanj]

There are no kits for those and I think there are two threads , go to Motogrid and look up the part number then check the cross reference list

[Scott S]

 Apparently it's a one year item. Just my luck.

 If I'm not mistaken, the threads are larger...19mm?  Someone correct me if I'm wrong. Those affordable aftermarket petcocks sure would be nice.

 I cleaned this one well and made sure all the seals and gaskets were seated correctly. So far, it seems to be doing OK. I could probably stand to change the needle valve on the #4 carb, as it seems to be the offender. But, I know the petcock was leaking by when in the OFF position previously.

[dave500]

david silvers has the filter kit which includes the nut and packing and the gasket for the filter tube,the tap thread is left hand,only nip it up,that tap is used on the f,k and k1 according to motorgrid,the other models threads probably are the same but the angle of the outlet nipples changed or single outlet nipple?

http://www.davidsilverspares.co.uk/CB550F-SUPER-SPORT-1976-USA/part_69923/

[Deltarider]

Good info, Dave. People that are tempted to have an inline filter, should consider ordering that set.

[Scott S]

 Temporarily out of stock.....shoot.

[Scott S]

 This one is M18 x 1.0mm. Is that the correct size?

http://www.ebay.com/itm/Honda-Replacement-Gas-Fuel-Tank-Petcock-Assembly-16950-HC4-840-/160919438772?vxp=mtr&hash=item25778bc5b4

 Can anyone tell me if I need 18 or 19mm?

[luap]

IMO no thats petcock wont work, the one your looking for if the 100.00 one that only pops up on egay everyone in a while.

[dave500]

i think the one in your link is a 400 one,the outlets go sideways not vertical?

[Scott S]

 I can deal with the outlets. I can even make a "T" to go from one to duals. I just need the threads to match.

[dave500]

im guessing the 400 and 550 tank threads would be the same,,i wouldnt buy anything untill i knew for sure though.

[Scott S]

 OK, the DSS petcock kit is in stock, but I'm wondering if it will cure the leaking petcock?

 The little D shaped gasket in mine is there but kind of wavy. The O-ring in mine was missing or rotten so I used one from an O-ring assortmet. It's definitely not like the one in the kit. Does that seal the petcock from leaking into the fuel hoses?
 FWIW, it's not leaking around the tank, but leaking into the carbs when in the "OFF" position.

 Yes, yes, yes....I know the needle/seats should stop fuel flow, but that's a separate issue I'm dealing with.

[dave500]

the ring that comes in the filter kit is square profile,it gets crushed between the tank outlet and the tap,when i pulled mine apart the po had electrical tape trying to do the job and the circular base was broken off the filter tube!

[Scott S]

 This is all that comes in the kit.


 As stated before, the little D shaped gasket is sort of wavy on mine and I'm using a generic O-ring. Is it worth $30+ to try this kit? If those two rubber pieces are the problem, fine....if it's the cone shaped selector, I just wasted my $$$.
 Would those two rubber pieces let the fuel leak past to the carbs, or are they just sealing it to the tank? It appears the O-ring seals it to the tank and the D gasket seals it to the filter.

[KennyRedman]

I'm curious, too.  I have the same type of petcock on my tank and it's leaking a bit as well.  It sucks to have to pay $30 for a couple of little gaskets.

[Scott S]

 If I knew for sure that would cure it, I'd spring for it today. I'm just afraid it might be the cone shaped "valve" inside and not the gaskets.

 Is yours leaking around the tank or past the valve to the carbs?

[dave500]

those rubbers just seal the tap to the tank outlet,the inside cone shape is the valve,if it looks scored you might be able to use wet or dry and smooth it and its tapered recess a little?

[Scott S]

 Well, I broke down and spent $99.90 shipped for a genuine Honda petcock. Figured that was cheaper than all the gas I was losing or burning down my garage.

 Here's another option, though:
http://www.ebay.com/itm/221171456740?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2649

 CB750 petcock. Correct 19mm threads but only one outlet. Thought about this one, but my the time I got it and a fuel T, I was within $25 of getting the real deal. Might work for someone that really needs one and the 550 petcock isn't readily available.

[wowbagger]

I have a cb500 with this exact petcock. Mine also leaked in the off position. It was also missing the strainer set that goes into the tank. I ordered the new strainer set pictured above but the leak was caused by the little plastic washer that sits between the screw plate and the lever. I ended up cutting a new washer down to size that was just slightly thicker than the original one. Works great and fixed the leak for about $0.12.

[Scott S]

 I asked that question earlier in this thread. I'm glad it worked for you, but I believe mine was leaking around the conical part inside the main body, not the gasket. I wish I had tried your fix before ordering a new one, though.
 My petcock probably would have worked OK with carbs that had good needle/seat valves. This bike was literally built from spare parts and the carbs could use new needles/seats, I'm sure.

 Anyway, here's what $99.90 gets you. I read the warning that came with the new petcock and thought "No sh!t....".

[KennyRedman]

Ha, that's funny. Where did you end up getting it from?

[Scott S]

 Ebay. This seller:

http://www.ebay.com/usr/dgs38

[riverfever]

I'm resurrecting this thread because I have the exact same PC valve. The valve was not leaking but I pulled it off the project bike/tank I'm working on right now because I rebuilt the carbs, I'm putting knee dents in the tank and cleaning the inside of the tank out and figured I'd clean this part as well. This is what I pulled apart and how it was situated. I am not positive that the PO had it together correctly.



Now...dave500 states that the square profile ring should be placed between the tank outlet and large nut but mine was under the lever for off, on and reserve. In the nut there was a typical o ring. I'm trying to figure out if I should bother trying to rebuild this valve or just get an adapter nut from Dime City Cycles which will reduce the tank bung to 1/4" NPT? This would allow me to run a newer style PC valve but I would need to run a t fitting for the dual fuel lines.

I do not know if this part from DCC will help me rebuild the existing valve.
http://www.dimecitycycles.com/vintage-cafe-racer-bobber-brat-chopper-custom-motorcycle-fuel-tank-parts-honda-cb125-cb200-cb350-cb360-cb450-rubber-petcock-grommet-16956-283-000.html

I am also missing the d shaped gasket but I see that comes with the DSS kit. What would you all recommend that I do here? Thanks.

[wowbagger]

To the best of my knowledge, there are no rebuild joys for these style petcocks. Honda only used them for about two years before switching to a different type. Use the fiche to determine the order of assembly for the parts you have.

http://www.cmsnl.com/honda-cb550f-super-sport-550-four-1976-usa_model467/partslist/F++12.html#results

On my cb500, I didn't have enough room for the adapter nut and a different petcock. By that point the fuel outlets were too low for the gravity fed carbs.

[riverfever]

So what did you do? Different tank?