Petcock info from Randakk. the lesson is...Shut it OFF !

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gltriker
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Petcock info from Randakk. the lesson is...Shut it OFF !

Post #1 by gltriker » Sun Feb 11, 2018 6:20 pm

I was just checking out Randakk's Cycle Shakk website, and discovered this recently added, Tech Tip. tumb2

The first photo is key.
http://www.randakksblog.com/motorcycle-petcocks-101/

edit: within that Tech Tip is a somewhat hidden link, too.
https://en.wikipedia.org/wiki/Hydrolock
Last edited by gltriker on Mon Feb 12, 2018 1:06 am, edited 3 times in total.
Cliff

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
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RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
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Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome
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Re: Petcock info from Randakk!

Post #2 by robin1731 » Sun Feb 11, 2018 7:53 pm

I've been saying that for years.

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #3 by gltriker » Mon Feb 12, 2018 12:05 am

tumb2
robin1731 wrote:I've been saying that for years.

.

I've been practicing it for years. Occasionally, we hear of some unfortunate soul that hasn't.

You can preach to some folks what may happen if a cylinder becomes hydraulically locked, and they won't comprehend what you are talking about. :-?

A photograph of a bent connecting rod is certainly a good visual representation, though. tumb2
Last edited by gltriker on Mon Feb 12, 2018 12:55 am, edited 3 times in total.
Cliff

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST :oldies

RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
"Can't see the paint when your looking thru the handlebars..........." -Oldewing ;)
"I'd rather Ride than Shine" -RAT tumb2 Me Too!!

Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome
https://www.youtube.com/watch?v=FVpommgI-M8 turn up your speakers volume YouTube video from April 12th, 2014

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.

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Re: Petcock info from Randakk!

Post #4 by JamesPal » Mon Feb 12, 2018 12:36 am

I'm on my third restoration. Never had a carb blockage or leaky petcock. I always line my tanks with Caswel, rebuild my petcocks with Randak seals.
"If everything is under control you are not going fast enough" - Mairo Andretti

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Re: Petcock info from Randakk!

Post #5 by robin1731 » Mon Feb 12, 2018 6:46 am

JamesPal wrote:I'm on my third restoration. Never had a carb blockage or leaky petcock. I always line my tanks with Caswel, rebuild my petcocks with Randak seals.


The guy that owned the CBX I put a rod in last year had never had a leaky petcock either. ;)

I keep that one around to show people. Two seconds to turn it off compared to a bill of over $1000.00.

.
1975 GL1000 parts bike (parts for sale)
1976 Goldwing Super Sport
1985 Honda Elite
1976 KZ900 Dragbike
1992 ZX7 Dragbike (KZ900 style motor w/NOS)
and a rotation of various purchases
Randakk approved Carb Rebuilder

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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #6 by ericheath » Mon Feb 12, 2018 8:51 am

My “Wall of Shame” pics:
8ED5F76F-FEB4-4FB4-B510-98B8F048302D.jpeg
117C8363-2541-4FB3-AA5E-94A0C082FEDE.jpeg


Top view shows how a 1200 piston should come above the top of deck.(block) Bottom is of a piston after an attempt to start where the motor turned over quite a bit before getting slammed to a stop. Both pics show the piston at TDC. There was a crisp “crack” or “whack” sound when it stopped. I didn’t know I did this until the head gasket went a few hundred to a thousand miles later.

I have been thinking of bringing the block into the basement and tearing it down to see how bent the rod is on mine and what’s needed for a rebuild. It is -30 C this morning. It’s not going to happen today.
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #7 by Wangthang » Tue Feb 13, 2018 9:39 am

Way back in the eighties my neighbor had a beautiful shovel. He got up one morning for work, kicked it, and it exploded. Blew him off the bike, and it burned up. I will always turn mine off even if i only to go inside a store.
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #8 by Gowing » Thu Feb 22, 2018 7:12 am

It’s really a bad feeling when you own a bike with a vacuum petcock. There is no on off.
My fj1100 had one. Many bikes have them. The club recommended replacing with a new $170
petcock, when it failed. Some replaced with an aftermarket pingel, etc. No rebuild kit available for fj1100. The only thing I disliked about my bike.
Dave

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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #9 by salukispeed » Thu Feb 22, 2018 12:40 pm

Including the bent rods It has been mentioned before that this could be contributing to more of our failed head gaskets then we know . The condition creates incredible pressures and forces in the cylinder and often the engine survives only to fail later
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #10 by Dirty Dave » Thu Mar 08, 2018 11:41 am

Had a hydrolock situation once with my Valkyrie even though the vacuum petcock was in the off position. Replaced it with a Pingel for peace of mind. I was lucky enough to have smelled gas and didn't try to turn the bike over. Am I to understand that the needle valves wouldn't allow gas to leak into the cylinders if in good shape? I cleaned my carbs just in case and never looked back.
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #11 by desertrefugee » Thu Mar 08, 2018 11:58 am

The Valk generally weathers a hydrolocked cylinder better than the 4 cylinder wings. Often, no damage results, but if it does, the result is chewed up starter gears instead. Still requires a motor extraction to repair, but better than rebuilding a bottom end.
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #12 by Sidecar Bob » Fri Mar 16, 2018 12:09 pm

Fuel hydrolock is caused by a leaking float valve, not a leaking petcock. A leaking petcock can't contribute to hydrolock unless the petcock was turned OFF when it happened and (on a 'Wing at least) the tank was at least half full (below that fuel can't flow into the carbs by gravity) and even then if the float valves are all doing their jobs nothing will get past them.

Shutting off the petcock will prevent fuel from flowing into the system and past a leaking float valve, though.

And Hydrolock isn't necessarily caused by fuel, either. A few years ago I tried starting my 'Wing the first time in the spring to find that it wouldn't turn over and when I removed the plugs I found one cylinder full of coolant. (Since "hydro" means water this is true hydrolock).

I've been thinking about this since I found the bent rod in the 1100 engine I started working on last year: My old (1000) engine was hydrolocked at least twice (if you find fuel in the plenum check the carb to plenum seals!!!) and, while it is still smoother than the CX's v-twin, I don't think it is as smooth as it was 20 years ago. And its mileage fell off noticeably about when the carb to plenum seals failed, which could be consistent with poorer compression resulting from the piston not reaching TDC. I'm thinking it might be interesting to check the compression before I swap in the new engine unless there any other way to determine if a rod is bent without removing the heads.....
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #13 by gltriker » Fri Mar 16, 2018 2:32 pm

Sidecar Bob wrote:Fuel hydrolock is caused by a leaking float valve, not a leaking petcock. A leaking petcock can't contribute to hydrolock unless the petcock was turned OFF when it happened and (on a 'Wing at least) the tank was at least half full (below that fuel can't flow into the carbs by gravity) and even then if the float valves are all doing their jobs nothing will get past them.

Shutting off the petcock will prevent fuel from flowing into the system and past a leaking float valve, though.

And Hydrolock isn't necessarily caused by fuel, either. A few years ago I tried starting my 'Wing the first time in the spring to find that it wouldn't turn over and when I removed the plugs I found one cylinder full of coolant. (Since "hydro" means water this is true hydrolock).

I've been thinking about this since I found the bent rod in the 1100 engine I started working on last year: My old (1000) engine was hydrolocked at least twice (if you find fuel in the plenum check the carb to plenum seals!!!) and, while it is still smoother than the CX's v-twin, I don't think it is as smooth as it was 20 years ago. And its mileage fell off noticeably about when the carb to plenum seals failed, which could be consistent with poorer compression resulting from the piston not reaching TDC.

I'm thinking it might be interesting to check the compression before I swap in the new engine unless there any other way to determine if a rod is bent without removing the heads.....


Occasionally I'd pondered that question, too, Sidecar Bob. ;)
I know there are precision measuring depth indicators to determine piston top location through an assembled engine's angled spark plug hole. But, I no longer have the rig I utilized on 2 stroke engines, many moons ago.

Then I thought of an adjustable piston stop that would be utilized in a 4 stroke engine.
Here's an example.
cca-4795.jpg

I don't have a disassembled GL engine to review the combustion chamber elements and test it on though, and no I'm not volunteering to remove a cylinder head on the trike. :IDTS:

Certainly not as accurate as the dial indicator rig, but a ball park comparison procedure could be formulated, if valve heads' interference and piston top irregularities (the GL valve relief pockets) wouldn't be problematic issues in the process. A too steep spark plug hole angle may be prohibitive, too. :dunno:
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Cliff

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST :oldies

RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
"Can't see the paint when your looking thru the handlebars..........." -Oldewing ;)
"I'd rather Ride than Shine" -RAT tumb2 Me Too!!

Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome
https://www.youtube.com/watch?v=FVpommgI-M8 turn up your speakers volume YouTube video from April 12th, 2014

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.

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Sidecar Bob
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #14 by Sidecar Bob » Fri Mar 16, 2018 4:39 pm

Sounds like a compression test would be the easiest way.....
Mr. Honda ('83 GL1000/Dnepr) summer
The Famous Eccles ('84 GX650EI/Velorex700) winter Never Ending Build (CX500forum)
Click: Colour schematics for all GL1000 & GL1100 and GL1200 standard models plus instructions on how to download the full size version
Image "A guy with two sidecars can't be all bad." - Cookie
Another guy with two sidecars..... Hmmmm... must be something to that....

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gltriker
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Re: Petcock info from Randakk. the lesson is...Shut it OFF !

Post #15 by gltriker » Fri Mar 16, 2018 4:41 pm

Please provide results, Bob. tumb2
Cliff

Keep your eyes and ears open and you'll learn something new, everyday. tumb2

New users please visit our "Shop Talk" for common tips and help: <---jdvorchak
http://www.ngwclub.com/forum/page/ST :oldies

RE: a thorough fuel tank cleaning
"And your carbs will thank you. They no longer live down stream from a sewage plant." -gregforesi tumb2
"Can't see the paint when your looking thru the handlebars..........." -Oldewing ;)
"I'd rather Ride than Shine" -RAT tumb2 Me Too!!

Cliff

'75 GL1000 home built trike; http://www.ngwclub.com/forum/viewtopic.php?f=30&t=39996
October,2017 BOTM :shock: https://nakedgoldwingsclub.com/forum/page/Welcome
https://www.youtube.com/watch?v=FVpommgI-M8 turn up your speakers volume YouTube video from April 12th, 2014

previous rides:
1953 H-D Servi-car, naked, 1969-1978 (serial#53G1559 committed to memory!)
1980 CB900 Custom (triked) 1997-2003 .... R.I.P.


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