Topic: 75 cb 550 petcock rebuild

[Chaser60]

I have this petcock


PO had rebuilt the oring just inside and behind the lever.  I could not turn the fuel on and off unless using a wrench, so he had used a slightly oversized oring.

I found one that seems to work and seal properly but now have a couple questions.   I will be using inline gas filters since the screen fabric is torn on the stand pipe.

In this picture there is a tiny slot (hard to see) that goes through from where the pen end to the inside of the fuel hole.   There is one like it on other side too.   Are they to be there or did PO mess the stand pipe up?


Also, there is an oring over the stand pipe (not shown on parts list) that looks like this


Without this oring, the stand pipe will pass right through the oring that is in the center of the nut which tightens the petcock to the tank.   My guess is that the oring in the nut is also wrong.  Find it hard to believe HONDA engineered a two oring sandwich to seal fuel.   Anyone know the facts here?   

lastly, I read a thread that said their is to be a small d-shaped gasket with two holes in it between the stand pipe and metal body of the petcock.   I fab'd one out of 1/16 inch rubber, but it really makes the entire assembly go together out of alignment.  (pipe is too high)  It would fit here and seal between the bottom of standpipe and petcock body.


The detailed picture on the various fiche's that are on line are not clear enough for me to see what is happening.   

So I', trying to figure out if stand pipe is ok to use as is with those slots(holes) and is the two oring sandwich proper or am I hunting for another oring for inside the nut?

Thanks for your ideas and help.

[riverfever]

I have the same one on my project bike and had similar issues. I rebuilt mine. Here's an exploded picture of mine as I was rebuilding it.



My sock filter was destroyed but I run inline filters so I wasn't too worried about that. I just didn't want there to be any leaks. As you can see, the gasket under the lever is more flat. I could never find that OEM anywhere so I ended up using an o-ring I found at True Value. It's been fine. I also replaced the o-ring that sits inside the large nut with one from True Value and it's also been fine. The lever turns very easy and no leaks. I also made a d shaped gasket (I hear this controls the switch from main to reserve fuel but am not positive). The concern I had with what I came up with (similar to what you have done) is that I did not want that rubber breaking down due to fuel and mucking up the freshly rebuilt carbs so I am not running it at all right now. I do not know if my reserve works but I'm also really not riding this bike yet so don't care much. As you can also see, I did not have a second o-ring on the pick up tube above that notched portion. If you put the petcock together on the bench as it would be on the tank and get that large nut tightened a bit, you will find that the pick up tube becomes tight. This is how I installed mine (together but loose) and then threaded it on the tank in increments.

I did find this but I was never 100% certain it would fit. That petcock seems to be a bit rare and was not used for long (so I've been told). When I looked, none of the replacements had the same thread size and I was going to have to use an adaptor. It looked like this would cause the lines to sit another 1/2" lower and I was worried about not having enough room for the fuel lines so I really wanted to make this petcock work (also had a lot of time in the tank and didn't want to abandon it). Seems to work right now. Let me know if you need any more help. I think I even have more pictures some where.

[Chaser60]

awesome and thanks.   my sock filter is trashed too so will probably just take the remains off.   did you happen to remember if your tube has those slotted holes from outer flange to inner gas feed holes that I tried to show in the picture with the pen.

thanks again

[riverfever]

I'm sorry but I can't recall what that end of the pick up tube looked like but I want to think mine did have holes and that's how the reserve works.