Hey guys!

So I've been thinking of repairing a leaking petcock for a while but I can't seem to find any good photos of the process, or even an exploded view of the petcock itself. There are several threads but no pics... Stupid as I was, I didn't document the process of inspecting the petcock properly to remember the correct order and besides, since it was leaking I'm not sure that it was correct in the first place. I'll happily document the process myself with decent photos and post here but I would like some help along the way, to see the order of the different parts. I guess I could figure it out too; after all it's an o-ring (which I guess is for sealing the petcock to the tank, a smaller seal/membrane, a bigger seal/membrane and spring, but still...

 

https://cbrforum.com/forum/f2-tech-9...-works-143899/

Best I can come up with.

 

Thanks, Mattson! It's a good start. I totally lack the plastic support disc so I doubt it is supposed to be there in the stock petcock...

 

This might help.

https://cbrforum.com/forum/how-mecha...ed-fix-152488/

If not, I may have an extra petcock in the basement I could take some pics of.

 

That would be awesome, Phil! The link was great too, but the poster spoke about the plastic disc and I don't know why this tank doesn't seem to have one... But it might explain why the bike is running better with the stock one than with the spare tank I bought from a scrapyard.

 

Here's some pics of the F2 petcock. The parts are in order of assembly. Pics are big, but that way you can see the detail.

In this pic, the part sides toward the camera face away from the spring.
https://dl.dropboxusercontent.com/u/...926_184759.jpg

In this pic, the part sides toward the camera face towards the spring.
https://dl.dropboxusercontent.com/u/...926_184821.jpg

First piece goes like this. Port at top is a vent and should face straight down when you are finished.
https://dl.dropboxusercontent.com/u/...926_184941.jpg

The 2 important things to get right are the direction of the large diaphragm and the plastic disk. The large diaphragm a ridge around the outside on one side. That side fits into the groove in the metal port. The nipple on that side is also larger and faces the metal connector that goes through the center of the metal port.

So put the smooth side of the plastic disk against the smooth side of the large diaphragm. Should look like this.
https://dl.dropboxusercontent.com/u/...926_185211.jpg

Then snap the large diaphragm to the small diaphragm through the center of the metal port. Should look like this.
https://dl.dropboxusercontent.com/u/...926_185047.jpg

Finally attach the previously assembled parts to the petcock body. Then add the spring and cover plate and screw it all together.
https://dl.dropboxusercontent.com/u/...926_185246.jpg

Vacuum port on the cover plate should face forward. It's a pain to hold it together, so have screws and screwdriver ready.

 

Phil, I am forever in you debt. Thank you so much for this effort. Now I can stop wasting time trying to figure it out by myself as it seems like I'm not only missing the plastic disc but the metal port as well. No wonder this petcock has been giving me headaches. I'll try to find the parts, or worst case, transplant the working petcock from the stock tank to the one I would like to use. At least I have some rubber parts in case I ever have to repair the working petcock.

Once again, a big thanks. Greatly appreciated!

Oh, totally off topic but here is a pic of the tail at the moment. I am still working (although moving forward very slowly) on the new skateboard based seat but as you can see, you can shorten the tail by several inches without cutting into the frame at all. I think it looks good a bit shortened.

 

If you order a Honda oem cover set 16953-MBZ-B51, you'll get all the parts, not just the diaphragms.

 

Phil, bought that set last week and today I replaced it according to your instructions. Easy as apple pie. It should be a sticky! Thanks, man!