Topic: petcock rebuilt, still leaks, any ideas???

[shizzomynizzo]

So i bought the rebuild kit for the petcock on my 74 550. all parts went in pretty easy

then i put it on the bike and take it for a ride.  NO MORE HESITATION AT FULL THROTTLE AT HIGH RPM'S!!! YAY!!!

so i get home, park the bike, come back in a hour. I see a puddle of gas under the bike  ???maybe i left the petcock on? check it, NO i just paid 24 dollars for some $#!t rebuild kit that doesn't work

After examining the petcock closer, it appears the housing is a little warped. the kit stopped the gas from leaking outside the petcock, but now it lets fuel in the carbs even when it is in the off position. then the fuel dumps out though the overflow valves.

I am not going to pay 100 dollars for a new petcock (EBAY), and am thinking about picking up some universal fuel shut off valves (2) to run between the tank and the carbs.

http://lawnmowerpartsstore.ecrater.com/product.php?pid=3978014

does anyone see any problems this will create?

Thanks in advance for the input

[martino1972]

first off....if your fuel comes out of the overflow from a carb you might wanne fix that as well....

i would take that petcock apart again first and inspect if you got all the gasskets etc. in the right way.....

those lawnmower shut off valves won't give you enough fuel flow at high rpm....

[shizzomynizzo]

I have taken it apart like 5 times today. even in the off position (when it's off the bike) It dribbles out the fuel connections.

now about the fuel coming out the overflow, that has to do with the floats?

I am new to working on motorcycles and am very eager to learn. I took apart the carbs the first day i got it and cleaned then out real good. I adjusted the floats per the manual (22mm). I did not have a float level gauge, but used a steel ruler instead.

Since they are discharging fuel, do i lower (20 mm or 21 mm) or raise (23 mm or 24 mm) the float level to stop this from happening?

Thanks again for the input

[martino1972]

could be a couple of things.....the float needles can have some dirt in em from your petcock episode,the overflow pipes in your fuel bowls can crack...etc.   basically with the petcock on the carbs should not overflow....if the float setting is 22mm you should keep it at that...now,does she only leak when on the side stand or also when she is up right..??

[shizzomynizzo]

good question, it has happened a couple times, and its been on the side stand. Ill put her on the center and we'll see tomorrow morning.

what if it doesn't' do it on the center stand? everything's good, gas is just accumulating in cylinder 1 and 2 and then dumping?

[martino1972]

that would be a sign that you have to recheck your float height if it only does it on the side stand...and it will tell ya if the float needles are holding up correctly...

[seaweb11]

Did the kit come with a new....sorry don't know the technical name "bent wobbly washer"?
When you turn the valve does it feel stiff or does it rotate with no effort?
Does petcock leak from the bottom of bowl, or out the front?

P.S. Just went through this and I used water in the tank until I was positive I had it sorted
I had to fuss with mine for 2 days till it worked

[Patrick]

I just went through this when I rebuilt my petcock a month or so ago. Two things to check: As Seaweb suggested, check that spring washer. You can bend it a little to give it a bit more spring. It is, after all, more than 30 years old and has had pressure on it all that time. Second, when I screwed the face plate back on mine the new washer was a bit thicker than the 31-year-old washer I took out. When I tightened the bolts the face plate warped a little. I pounded it flat (actually a little past flat so the middle touched before the ends) and bent the spring washer a bit and now I have no leaks. The petcock turns smoothly, but not too easily.

It's worth a look.

Patrick

[seaweb11]

"Spring Washer" that's the ticket.

I stole one off an old CL350 Petcock and it solved my problems.  Do the kits not come with a new one?

[shizzomynizzo]

well it still dumped on the center stand. I am going to recheck the float levels and clean the needles again.

The kit did not come with a new warped looking washer, but ill try fiddling with this one to see if it does the trick.

Thanks for the help

[Patrick]

Two other things to look at. Make sure the inside face of the lever plate (the part that presses on the gasket) is polished up real good and the inside of the petcock where the new gasket rests is very clean. Debris from the old gasket or a buildup from old gas can hurt the seal.

[manjisann]

I rebuilt the petcock on my cb500 for the same reason, and even bought a new one before I realized what was wrong. Judging from the blow up at BB http://www.bikebandit.com/houseofmotorcycles/honda-motorcycle-cb550-1974/o/m9230 you should have 2 red washer like things (#13 I think) that go on before you put the screws in that connect the petcock to the gas tank. These ended up being the problem, I think they are metal with some sort of gas proof coating/sealer. If they leak it will act like your petcock isn't closing.

HTH,

Brandon

[shizzomynizzo]

Brandon,
thank you!!! 

Thats the problem with the petcock!!! no washers!!!

Martino, thank you too!  the floats were off even though I just did them. The ruler I was using had an extra couple mm below the start point on the one side, I flipped it around and remeasured and adjusted. the float on carb 2 was still dumping after readjustment; while dumping gas, I tapped with a screw driver and it stopped...I believe the spring was sticking.

I went to autozone and picked up a bottle of Seafoam. This $hit is amazing I put in half a bottle and rode up and down Telegraph (speed limit 50) and I immediately noticed a huge difference. It had full power with no hesitation from idle all the way through red line (only tried it once). It now is running the best ever. I have only had it for a week and am very impressed! This is my first Honda and I love it!

I have had a ducati 900 ss  (so uncomfortable to ride for more than 20 miles and the clutch really hurts your wrists at stop lights), a buell m2 cyclone  (too top heavy and too much vibration from the motor), sporster 883  (too low to the ground and not enough power) and a suzuki ts 250  (too old and slow and hard to find parts).
None of these bikes had any problems at all, I paid quite a bit for each, but was not happy with any of them.
This cb550 is BY FAR THE BEST OF ANY I HAVE OWNED!!!

BTW I was wrong when I said 22 mm. that is what is in the manual, but I actually adjusted them to 12.5mm. They must not be the original carbs.

  ???Any way of knowing what bike they're off? they look the same as all repair manual pics and go together the same and all. Maybe a later cb550
The motor is not the original one, it was replaced by the PO and I imagine he replaced the carbs too. from the number on the block, I think it is from the same year bike, (built in 73 sold in 74) the numbers on the vin and motor are only a few thousand apart.

[martino1972]

I love a happy ending....***wipes tear away***     

[manjisann]

  So this is what it's like to be right    Haha, seriously though, glad it helped. I had bought a rebuild kit, then a brand new setup before someone had suggested the little washers.

Pics help with IDing parts 

Brandon