Author Topic: My petcock is trying to kill me.  (Read 743 times)

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Offline Puntas13

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  • '73 cb500 '74 cb750 '09 Triumph Speed Triple
My petcock is trying to kill me.
« on: April 20, 2014, 04:14:32 PM »
My 750 had a leaky petcock from the git go. It would still dispense fuel even when turned off. I put it off.

One night i was awaken at 3:30am to the strong smell of gasoline(garage/apartment). It had puked 1.5-2 gallons of fuel onto my floor. If i would have had a gas hot water heater, my house without a doubt would have exploded.

So i picked up a set of nylon washers to replace the felt ones that were messed up. It fixed it.

Flash forward to yesterday. I put in a new clutch pack. All went smoothish and i took the bike out for a spin. Clutch was slipping at certain times. It shouldn't have. Everything was good to go.

Today when looking at the bike i noticed a puddle of raw gas.  There was a drip of fuel on one of my carb overflow tubes. I touched it and fuel came pouring out. The orings failed i guess. The overflow tube was plugged and it poured about .5 gallon of fuel into my cylinder and the oil level in my tank was all the more proof i needed.

This #$%*ing thing is coming off my bike.

Long story short, is there a good bolt on replacement outside of the OEM type?

Offline 754

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Re: My petcock is trying to kill me.
« Reply #1 on: April 20, 2014, 04:16:07 PM »
Put a clamp on your fuel line, then look for a petcock.
Maker of the WELDLESS 750 Frame Kit
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Kelowna B.C.       Canada

My next bike will be a ..ANFOB.....

It's All part of the ADVENTURE...

73 836cc.. Green, had it for 3 decades!!
Lost quite a few CB 750's along the way

Offline Johnie

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Re: My petcock is trying to kill me.
« Reply #2 on: April 20, 2014, 04:19:09 PM »
For the hazards you just mentioned, I install a new OEM petcock on each build. Just piece of mind I guess.
1970 CB750K0 - Candy Ruby Red
1973 CB750K3 - Candy Bacchus Olive or Sunflake Orange
1970 Chevy Chevelle SS396 - Cortez Silver
1976 GL1000 Sulphur Yellow

Oshkosh, WI  USA

Offline Lostboy Steve

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Re: My petcock is trying to kill me.
« Reply #3 on: April 21, 2014, 02:38:04 PM »
Indeed, I do the same. It just isnt worth it finding out the hard way when it comes to fuel.
1968 Honda Z50
1977 Honda CB550K
2018 Indian Scout

Offline nccb

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Re: My petcock is trying to kill me.
« Reply #4 on: April 21, 2014, 06:41:53 PM »
hell, didn't a guys bike go up in flames while he was riding it a year or so ago?

Offline PeWe

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Re: My petcock is trying to kill me.
« Reply #5 on: April 22, 2014, 03:14:41 AM »
The engine should not be overfilled with fuel even with petcock ON.
Floats must be wrongly adjusted/stucked or float valves not closing as they should to stop fuel to flow into the carbs and fill engine.
CB750 K6-76  970cc (Earlier 1005cc JMR Billet block on the shelf waiting for a comeback)
CB750 K2-75 Parts assembled to a stock K2

Updates of the CB750 K6 -1976
http://forums.sohc4.net/index.php/topic,180468.msg2092136.html#msg2092136
The billet block build thread
http://forums.sohc4.net/index.php/topic,49438.msg1863571.html#msg1863571
CB750 K2 -1975  build thread
http://forums.sohc4.net/index.php/topic,168243.msg1948381.html#msg1948381
K2 engine build thread. For a complete CB750 -75
http://forums.sohc4.net/index.php/topic,180088.msg2088008.html#msg2088008
Carb jetting, a long story Mikuni TMR32
http://forums.sohc4.net/index.php/topic,179479.msg2104967.html#msg2104967