Author Topic: CB350/360 petcock on a 550F tank?  (Read 786 times)

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Offline Scott S

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CB350/360 petcock on a 550F tank?
« on: August 23, 2019, 05:11:17 PM »
 I'm working on a CB550F and even though the bike is a '76, apparently the tank is from a '77. It uses the single outlet 16mm x 1.5mm petcock.

 I have one, but it's missing the filter screen and the fuel tee. The tee is no problem. The screen is about $30-35 but I can't seem to get the nut off the petcock to install a new seal and filter sock. Plus, I'd rather forego the tee if possible.

 I DO have a brand new, genuine Keihin dual outlet petcock that was used on the CB350/360, among others. It has the sediment screen and a brass filter on the reserve pipe, plus dual outlets.
 It looks like it would hang down lower than the 20mm petcock used on the '75-76 models, but is actually slimmer.

 Pictured below, left to right (when you click on it....top to bottom, otherwise): 20mm '75-76 petcock, 16mm CB350/360 petcock, 16mm '77 550F petcock.

 Has anyone used the dual outlet petcock on a '77 550F tank? Everything clear OK?

 How do I get the nut off the single outlet 16mm petcock to install a new filter sock? It just spins in place. I've tried regular and reverse threads. This petcock was on the tank when I got it. It was removed for paint.
« Last Edit: August 23, 2019, 05:13:21 PM by Scott S »
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Scott S

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Re: CB350/360 petcock on a 550F tank?
« Reply #1 on: August 23, 2019, 05:15:57 PM »
Here's the filter I'm talking about. Do it and the O-ring just sandwich in between the petcock and the tank?
 It's #3 in the diagram.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Scott S

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Re: CB350/360 petcock on a 550F tank?
« Reply #2 on: August 23, 2019, 05:28:38 PM »
 It's awesome being a parts hoarder.

 Ten minutes after posting this I found a good used sock filter for the single outlet petcock. It just pushes down on the tube.

 AND.... I found a brand new aftermarket 16mm petcock that I forgot I bought.

 I'd still like to know if the dual outlet CB350/360 petcock would fit and clear everything.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline bryanj

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Re: CB350/360 petcock on a 550F tank?
« Reply #3 on: August 24, 2019, 12:21:54 AM »
Only way to know is fit it and see
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!