350X Petcock Rebuild Step-By-Step

[wonderboy]

I recently rebuilt my 350X petcock. I wanted to post the step-by-step instructions and parts required in case anyone else wanted a guide to follow. This is a repost of my original thread (from memory) which was a victim of the database crash, so it may not look exactly like it did the first time.

Honda Parts Required:
4-Hole Washer: 16955-HA2-005
X-ring: 16963-HB9-005


Tools Required:
Dremel with grinding wheel (or similar)
Drill bit (#39) and then when that breaks and the store is out of more, just get a 3/32"
3mm x 0.5 Tap
1000-1500 wet/dry sandpaper
Carb cleaner (I use Berryman's Carb dip in the gallon can)


Other Parts Required:
M3x0.5 pitch screws, 10 mm long (x2) I used SS button head screws. They are nice and low profile and use an allen head.


Rebuild Steps:
1. Carefully grind off the heads of the rivets holding the plate on the front of the petcock. Don't be too agressive, and try to stay off of the front plate.


2. Remove the front plate, followed by the flat washer, the wave washer, the lever, and then finally the old 4-hole washer. Take a look at the old washer next to the new washer.


3. Remove the old X-ring washer from the lever.


4. Now is the time to dump the metal parts (petcock body, lever, and front plate) into the carb dip carb cleaner to clean them all up. Once you're happy with the parts, take the lever and clean up the back side with a piece of wet/dry sandpaper (I used 1500). The back side of the lever is what seals against the 4-hole washer, so make sure it is smooth, clean, and polished (within reason). Mine was rough at first. The 1500 cleaned it right up. Be sure to wash off the lever really well when done.


5. Drill and tap the petcock body for the M3 screws. If you weren't too agressive in the grinding step (#1) you'll still have dimples in the center to help center the drill bit. Drill all the way through the body. Then tap the holes with the tap (always use oil with your taps). You could probably get away without tapping the holes, but you'd have to experiment with the proper size drill bit to use with whatever screws you are using. I like tapping the hole since it goes back togeher so nice. Again, wash this part really well to get rid of the oil and metal shavings.


6. Reassemble everything. Put the 4-hole washer into the body, follwed by the shut-off lever (with the X-ring installed), the wave washer, the flat washer, and finally the front plate. Use the screws to hold it all together.


Done!

[andersonee4]

Nice write up! Is there a reason for not drilling the rivets out, and re-riveting? or is this just your preference? Very nice pictorial

[wonderboy]

That's a really good question. I should have said "Rivets" (in double quotes). What honda did was to not actually use distinct sepparate rivets. The body of the petcock was cast with nubs that stuck out (the same dimeter as the holes in the front plate). When the entire getup was assembled, they mushroomed over the metal protruding past the front plate. I know there is a proper term for this, but I can't remember what it is. If you take a look at the second picture of step #1, you'll see the metal protrusions I'm talking about. These are actually all part of the body casting.

[andersonee4]

Ahh.. Ok thank you for clearing that up, i would've tried to drill it out, and been wicked ticked.

[Speedgoat]

I realize this is an old thread but why not just buy a new one? Do the aftermarket replacements not work well?

[atcmatt]

Genuine is always better!

[ctk]

These are great. I have 3. Awesome job frank

[wonderboy]

Hey, oldie thread for sure. I am a big fan of keeping the original parts on the machine. And typically, I feel like OEM parts just fit and function better than the aftermarket parts. Of course there are exceptions, but in this case, it only costs about $20 in parts to get the original in back to new condition. One step that you don't see in my original thread, but CTK has seen is that I bead-blast these as well so they truly look like new once done.

[ironchop]

This should be a sticky

Sent from my Z958 using Tapatalk

[NeverLift]

I'm glad you revived this. My Tri-z petcock leaks and Yamaha lists it as non rebuildable part. I've taken all 4 i own apart and am using the best 1 and it still leaks. These look like the exact parts i need both petcocks are Keihin so there's hope. I will order the parts and post my results.

[NeverLift]

It Works for the Tri-z. No more leaking cock.

[RapidRick]

Thanks for the repost

[Ranvier]

Bump. Tried to go for a ride and had a big leak. Any luck with the aftermarket cheap replacements? I plan rebuilding oem but so many projects...

[atc300r]

Bump incase anyone needs the part numbers and info.

[wwivhobbit]

I realize this is an old thread but why not just buy a new one? Do the aftermarket replacements not work well?

This is an old thread and nobody will probably see this, but there's a really good reason not to use any of the aftermarket ones on ebay and elsewhere. The
stock petcock has a spigot with about an 8.5mm outer diameter and the aftermarket ones about maybe 5 or 6mm diameter at most. I found one that was advertised
to be 7mm, but that's far smaller than the stock one. On a stock machine that's just trail ridden that's probably not an issue, but in my case I'm running a 450 carb which
is like 10mm larger than stock and has a huge gas line. I would prefer to use the 450 petcock to match but haven't decided which way to go with the tank mod to
make it work, so using the stock one for now. Hope this helps someone down the line