Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Fuel System

Reply
 
Thread Tools Display Modes
  #1   IP: 174.89.31.125
Old 07-26-2015, 07:18 PM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
Carb Gasket

Finished rebuilding fuel pump and carb.
Benefits noticed include being able to adjust carb so lowest throttle position will allow me to creep forward, instead of always sliding into neutral. Also, when I removed the fuel pump I thought I had good action, as it was, but with the new springs, wow! Stiff priming lever, and it delivers 4.75 psi on gage. Very happy with it all.

One question- the gasket supplied to seal upper/lower section has a bit of overhang, and is weeping/soaked in fuel. Just leave it, or best to trim off excessive? I am quite certain I have a good seal between the two pieces, and what I am seeing externally is from a "wicking" effect.

Admittedly I may be hyper sensitive to this now, but I would prefer to error on the side of caution.

Cheers
Jimmy
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie
Reply With Quote
  #2   IP: 184.0.17.64
Old 07-26-2015, 07:36 PM
roadnsky's Avatar
roadnsky roadnsky is offline
Afourian MVP
 
Join Date: Dec 2008
Location: Lake Mead, NV
Posts: 3,104
Thanks: 24
Thanked 467 Times in 309 Posts
Jimmy-
In my experience (IME) that dark area is normal. (See pic)
The pic is a rebuild after 2 years. If you look closely, you'll see the "darker" area on the excess gasket.
I'm not sure why it shows as a darker area.
Note that the "inside" area is lighter in color.
Attached Images
 
__________________
-Jerry

'Lone Ranger'

1978 RANGER 30

Last edited by roadnsky; 07-29-2015 at 10:15 AM.
Reply With Quote
  #3   IP: 68.111.9.124
Old 07-27-2015, 01:41 AM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
Quote:
Originally Posted by Jimmy View Post
One question- the gasket supplied to seal upper/lower section has a bit of overhang, and is weeping/soaked in fuel. Just leave it, or best to trim off excessive? I am quite certain I have a good seal between the two pieces, and what I am seeing externally is from a "wicking" effect.
Admittedly I may be hyper sensitive to this now, but I would prefer to error on the side of caution.
Jimmy
Did you get the gasket from Moyer? Unless the gasket is made from the correct material it will wick fuel as you observed.
The only way to tell for sure is to take the two halves apart and see if there is a seal all around like in Jerry's picture.
IMO you are not being hyper sensitive. Don't blow the boat up.

TRUE GRIT
Reply With Quote
  #4   IP: 174.89.31.125
Old 07-27-2015, 06:45 AM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
Gasket was included in rebuild kit from MM. Will return tomorrow to check and snap photo

Worth noting that the MM manual is one of the best written collection of instructions I've ever used. Most valuable tool on board!

Cheers
Jimmy
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie
Reply With Quote
  #5   IP: 207.118.20.35
Old 07-27-2015, 11:21 AM
capnward's Avatar
capnward capnward is offline
Afourian MVP
 
Join Date: Aug 2012
Location: Deer Harbor WA
Posts: 335
Thanks: 41
Thanked 147 Times in 107 Posts
4.75 on the gauge seems more than usual or necessary. I doubt you would get that reading when running, only when priming with the pump lever. This may be forcing fuel past the gasket, with or without an overhang. Even so, this is a serious situation. A gasket should not wick fuel. If the seal is indeed good, it will not leak, even at 4.75 psi. If this persists, try seeing if you can tighten any of the bolts around the gasket. If they are all tight,you may have an irregularity in the surfaces of the carb.
Reply With Quote
  #6   IP: 107.0.6.242
Old 07-27-2015, 01:19 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Talking

Quote:
Originally Posted by capnward View Post
4.75 on the gauge seems more than usual or necessary. I doubt you would get that reading when running, only when priming with the pump lever. This may be forcing fuel past the gasket, with or without an overhang. Even so, this is a serious situation. A gasket should not wick fuel. If the seal is indeed good, it will not leak, even at 4.75 psi. If this persists, try seeing if you can tighten any of the bolts around the gasket. If they are all tight,you may have an irregularity in the surfaces of the carb.
I agree. A less than perfect mating between the two halves of the carb body coupled with a float set too high could mean trouble. Does your carb have 4 or five machine screws holding the two haves together?
Reply With Quote
  #7   IP: 32.211.28.40
Old 07-27-2015, 06:16 PM
Al Schober's Avatar
Al Schober Al Schober is offline
Afourian MVP
 
Join Date: Jul 2009
Location: Uncasville, CT
Posts: 2,002
Thanks: 16
Thanked 578 Times in 405 Posts
That gasket shouldn't wick, even with the overhang.
First thought is that something is hanging up and not letting the two halves come together. Perhaps the venture tube isn't fully seated? I'd try putting it together without the gasket to make sure everything comes metal to metal.
I've seen gaskets wick. We had oil wicking with Navy specified gasket material - 1/8" thick neoprene with canvas reinforcement. Oil was following the threads in the canvas. Navy wouldn't believe us - tied up our lab for a month proving what we knew.
Reply With Quote
  #8   IP: 174.89.31.63
Old 07-27-2015, 07:03 PM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
Red face

OK- mea culpa.....
I had to remove the fuel strainer bowel to access the second/rear bolt on the pump. When I put it back together, didn't realize the rubber seal slipped out. Subsequently couldn't get engine to fire up. I primed repetitively, but no fuel flow ( yea- massive air leak will do that). After diagnosing the issue( and retrieving/installing the lost seal from the bowels of the boat), the carb/ fuel system primed quickly
Some observations..........

Carb has 4 screws to mate the 2 halves
I traditionally over tighten- snapping and striping bolts as I go thru life. Aware of the warnings about soft alloys involved, I didn't this time, however confident I tightened enough.
Float was exactly parallel with mating surface, when held upside down.
Initial prime pressure = 7psi
During running/tuning = 4.75 psi
After shutdown, pressure stayed above 4 psi for at least 30 min.Wasnt taking exact notice of reading, but thought that is was great that the system was staying pressurized for so long......

Is it possible at 7 psi (even temporarily)I have "overloaded" the gasket?

Thoughts?

Fume detector w/ blower relay has been ordered. Hopefully delivered tomorrow

Cheers
Jimmy
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie
Reply With Quote
  #9   IP: 107.0.6.242
Old 07-27-2015, 08:29 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Question

If your needle and seat are holding 4 psi for 30 minutes after shutdown, they are at the head of the class. When the fuel chambers of the carb are full and the needle and set have stopped the inflow of fuel, the gasket should not be exposed to fuel at all. Does your leak/wicking persist after shutdown or does it occur only when the engine is running?
Reply With Quote
  #10   IP: 32.211.28.40
Old 07-27-2015, 08:41 PM
Al Schober's Avatar
Al Schober Al Schober is offline
Afourian MVP
 
Join Date: Jul 2009
Location: Uncasville, CT
Posts: 2,002
Thanks: 16
Thanked 578 Times in 405 Posts
To clarify hanley's post, the gasket will be exposed to fuel as the boat rocks and plunges through the waves but the pressure stops at the float valve. The float bowl, gasket, and the carb internals are all basically at atmospheric pressure. With the engine running, there's airflow through the venturi which changes things (and moves the fuel), but that's all low pressure stuff. I saw a document somewhere (Moyer Manual??) that described flows and pressures in the carb at wide open throttle. Kinda went over my head. In my book, it the carb don't work, clean it out (done it a lot lately).
Reply With Quote
  #11   IP: 107.0.6.242
Old 07-27-2015, 09:23 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Quote:
Originally Posted by Al Schober View Post
To clarify hanley's post, the gasket will be exposed to fuel as the boat rocks and plunges through the waves but the pressure stops at the float valve. The float bowl, gasket, and the carb internals are all basically at atmospheric pressure. With the engine running, there's airflow through the venturi which changes things (and moves the fuel), but that's all low pressure stuff. I saw a document somewhere (Moyer Manual??) that described flows and pressures in the carb at wide open throttle. Kinda went over my head. In my book, it the carb don't work, clean it out (done it a lot lately).
Thanks for that Al. Yes, the gasket will get wet with the "rocking" but should not be under pressure. I wonder if that chamber is venting correctly?
Reply With Quote
  #12   IP: 107.0.6.242
Old 07-27-2015, 09:34 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
http://www.moyermarine.com/forums/showthread.php?t=242 This is a great reference.
Reply With Quote
The Following User Says Thank You to hanleyclifford For This Useful Post:
Administrator (07-28-2015)
  #13   IP: 174.89.31.63
Old 07-27-2015, 10:09 PM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
Hanley/Al - thanks for the link.
As I have only run the the engine Sat/Sun, I can't say with certainty that the problem is persistent. Proof will come with tomorrow's inspection.
With the info you have added, I will check for a gap at the front of carb.
I'll post a picture of my findings. Extra eyes can't hurt!

Cheers
Jimmy
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie
Reply With Quote
  #14   IP: 71.118.13.238
Old 07-28-2015, 11:39 AM
Dave Neptune Dave Neptune is offline
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Grove, Oklahoma
Posts: 5,035
Thanks: 711
Thanked 1,289 Times in 839 Posts
Hanley, the carb has an internal vent that feed to the throat chamber under/behind the venturi. I doubt it could get plugged.

I have "sealed" the ends of more than a few 4-screw carbs by running a bead of "hi temp orange or red" silicone around the end of the carb AFTER TESTING!!!! DO NOT USE THE PERMATEX SILICONE WHEN ASSEMBLING!! After the carb has been confirmed good remove and apply the bead on the outside. The one on my carb stays sealed and has for 4 years now others longer.

Worry more about sealing the emulsion well in the center first with a distorted "top half". They can be "flat honed" to reseal if you are careful. Done so many times out here for friends.

Dave Neptune
Reply With Quote
  #15   IP: 184.151.36.43
Old 07-28-2015, 07:39 PM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
OK- installed new water/fuel separator, than ran engine.
- before starting, checked gasket and gap. Gasket appeared to dry out, but still double checked front all 4 screws. Got a third of a turn. Attached picture is a 0.002 feeler gauge inserted. I am border line forcing it at this point.

Second pic is of fuel pressure gauge, with engine shut of for more than 15 min past.

Third pic is where gasket had become some what saturated, after engine ran 15 min. Not sure if you can make out the detail, but when I compress the external flange of gasket with fingernail, a slight sheen appears

PO had a little something added, that I cleaned up prior to resembling. It came clean using carb cleaner and a rag.

At this point, I am prepared to remove carb, redo with a little sealant, and go again.
Can I reuse the soaked gasket? Dry it out?
Agree?
Attached Images
   
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie

Last edited by Jimmy; 07-28-2015 at 08:06 PM.
Reply With Quote
  #16   IP: 32.211.28.40
Old 07-28-2015, 11:04 PM
Al Schober's Avatar
Al Schober Al Schober is offline
Afourian MVP
 
Join Date: Jul 2009
Location: Uncasville, CT
Posts: 2,002
Thanks: 16
Thanked 578 Times in 405 Posts
The first picture shows that you have the wrong gasket for your carb. You have a 4 screw carb, and the gasket for a 5 screw carb. And, the carb gasket should need NO sealant. I don't use any, and don't have a weepage problem.
Previous comment still holds - put it together without a gasket and make sure things come together.
Reply With Quote
  #17   IP: 159.53.174.142
Old 07-29-2015, 08:26 AM
Bratina Bratina is offline
Senior Member
 
Join Date: Jun 2015
Location: Toronto, Ontario
Posts: 96
Thanks: 126
Thanked 26 Times in 17 Posts
Quote:
Originally Posted by Al Schober View Post
The first picture shows that you have the wrong gasket for your carb. You have a 4 screw carb, and the gasket for a 5 screw carb. And, the carb gasket should need NO sealant. I don't use any, and don't have a weepage problem.
Previous comment still holds - put it together without a gasket and make sure things come together.
I believe that 5-bolt and 4-bolt carbs use the same gasket, per a note from Don / others. The old and new model carbs DO use a different gasket because they're entirely different shapes, but otherwise the 5-bolt gasket fits a 4-bolt carb just fine (e.g. the 5-bolt gasket in my 4-bolt carb).
Reply With Quote
The Following 2 Users Say Thank You to Bratina For This Useful Post:
Easy Rider (07-31-2015), ndutton (07-29-2015)
  #18   IP: 107.0.6.242
Old 07-29-2015, 02:37 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Smile

Look at those beautiful street fittings (from Moyer Marine, I'll warrant).
Reply With Quote
  #19   IP: 184.151.61.151
Old 07-30-2015, 09:47 PM
Jimmy Jimmy is offline
Senior Member
 
Join Date: Aug 2011
Location: London Ontario
Posts: 128
Thanks: 3
Thanked 15 Times in 5 Posts
Yup, got the fittings with the rebuild kit. Other than the deflated Canadian dollar, my other issue with ordering from MM is the time it takes to get goods north of the boarder. Neither of these issues are within the control of our Host, and I value this forum, and MM's ability to supply parts, so whenever feasible, I support them. Usually 1 significant shipment a year, of required parts, and a couple miscellaneous parts as I continue to build a reasonable spare part collection.
To this point, I won't get a new carb gaskets in time for Friday nights redo.... After making sure the float is correct, and halves are flush, I can choose to reuse the 3 week old gasket, or attempt to cut a new one from a template.
Which would you do, faced with these two options?

Cheers,
Jimmy
__________________

Jimmy
C&C 29 MK1
Erieau , Lake Erie
Reply With Quote
  #20   IP: 107.0.6.242
Old 07-30-2015, 11:25 PM
hanleyclifford's Avatar
hanleyclifford hanleyclifford is offline
Afourian MVP
 
Join Date: Mar 2010
Posts: 6,978
Thanks: 172
Thanked 280 Times in 226 Posts
Talking

I would attempt to reuse the old gasket. Hopefully you've been careful making sure it does not get torn when separating halves and getting that venturi out. On the 4 screw carb it's real important to get the two pieces plane for a tight fit. If it doesn't look good don't be shy about taking a flat bastard to one piece or the other. Check first with something known to be straight, like a stainless ruler or a square.
Reply With Quote
The Following User Says Thank You to hanleyclifford For This Useful Post:
Jimmy (07-31-2015)
  #21   IP: 71.118.13.238
Old 07-31-2015, 09:56 AM
Dave Neptune Dave Neptune is offline
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Grove, Oklahoma
Posts: 5,035
Thanks: 711
Thanked 1,289 Times in 839 Posts
Trix

Jimmy, if you are successful at getting the gasket out unscathed try this it's worked for me 100's of times on carb gaskets. First carefully wipe it clean and dry, then spray liberally with WD-40 and place in a sealed baggy. Get as much air out of the baggie as you can so the gasket stays wet and set it in the sun or someplace warm for at least an hour. The gasket as it warms will suck u some of the WD-40 and swell up a bit so it can be squished yet again.

DO NOT OVERTIGHTEN THE SCREWS, it just takes a slight pressure if things are flat!

Dave Neptune
Reply With Quote
The Following User Says Thank You to Dave Neptune For This Useful Post:
Vermonstah (08-05-2015)
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
carb gasket sealant? Marty Levenson Fuel System 8 06-17-2011 03:21 PM
Gasket for carb flange at engine lhbradley Fuel System 4 05-19-2011 09:38 AM
carb bowl drain plug gasket sastanley Fuel System 12 09-23-2010 07:21 PM
Carb mating gasket bayway27 Fuel System 3 04-29-2009 12:54 AM
5 bolt gasket on a 4 bolt carb? sastanley Fuel System 5 12-03-2008 01:22 PM


All times are GMT -4. The time now is 08:19 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved