Return to the home page...

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

Reply
 
Thread Tools Display Modes
  #1   IP: 174.212.25.143
Old 07-18-2018, 08:15 PM
Fstued's Avatar
Fstued Fstued is offline
Senior Member
 
Join Date: Jan 2014
Location: Ocean Beach
Posts: 65
Thanks: 27
Thanked 0 Times in 0 Posts
Weird Problem with Carb?

I can move the acceleration lever on my carburetor at the carb and not see any increase in my RPMs. This doesn't happen all the time just every once in awhile. Very strange. Then in a bit the RPMs will kick in. To continue with the problem I can be in gear and moving forward at maybe 1200 rpm at 3 or 4 kph. Then I increase the rpm to 15 or 1600 rpm and there is no speed increase. I am guessing the clutch is slipping so I tightened it one notch and no change.
I rebuilt the engine last year and have 38 hrs on it. It was running fine just a few days before. Any one have any guesses on this conundrum
Thanks
Reply With Quote
  #2   IP: 72.194.219.196
Old 07-18-2018, 08:28 PM
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
Is the prop clean? Or maybe there is some garbage wrapped around it. Also is the stuffing box running hot while in gear? This would indicate the packing is to tight.
Try shifting into forward by hand using the lever on side of the trany. Maybe the trany is not fully in forward because the linkage is not adjusted correctly. or the trany nay need an adjustment.

TRUE GRIT

Last edited by JOHN COOKSON; 07-18-2018 at 08:34 PM.
Reply With Quote
  #3   IP: 138.207.175.58
Old 07-18-2018, 09:07 PM
Administrator's Avatar
Administrator Administrator is offline
MMI Webmaster
 
Join Date: Oct 2004
Location: Chestertown, MD (Langford Creek)
Posts: 2,198
Thanks: 1,335
Thanked 365 Times in 182 Posts
In neutral, if you crank the throttle up sharply, does the engine RPM respond dramatically?

Try putting it in reverse and giving the engine a healthy shot of power. We have picked up a clump of grass which produced the symptoms you describe. A quick burst of power in reverse threw off the grass, and everything returned to normal. Years ago, it was an old tee-shirt. That one forced me over the side to remedy the problem.

HTH.

Bill
Reply With Quote
The Following User Says Thank You to Administrator For This Useful Post:
Fstued (07-19-2018)
  #4   IP: 71.244.230.46
Old 07-19-2018, 06:23 AM
sdemore sdemore is offline
Senior Member
 
Join Date: Nov 2016
Location: Pasadena, MD
Posts: 230
Thanks: 84
Thanked 43 Times in 33 Posts
Does it act the same in neutral?
__________________
Steve Demore
S/V Doin' It Right
Pasadena, MD
Reply With Quote
  #5   IP: 137.200.0.112
Old 07-19-2018, 07:53 AM
joe_db's Avatar
joe_db joe_db is online now
Afourian MVP
 
Join Date: May 2009
Posts: 4,474
Thanks: 49
Thanked 1,026 Times in 721 Posts
Have you got a helper, taken the flame arrestor off, and figured out if there is an actual mechanical issue with the throttle plate not moving correctly?
Reply With Quote
The Following User Says Thank You to joe_db For This Useful Post:
Fstued (07-19-2018)
  #6   IP: 99.65.97.191
Old 07-19-2018, 10:19 AM
Fstued's Avatar
Fstued Fstued is offline
Senior Member
 
Join Date: Jan 2014
Location: Ocean Beach
Posts: 65
Thanks: 27
Thanked 0 Times in 0 Posts
I'll check the prop to make sure it is clean. I also remove the flame arrestor and check the carb throttle and make sure the linkage is working properly on the mechanical workings in the carburator. I really don't want to remove the carb. Thanks everyone
Reply With Quote
  #7   IP: 72.194.219.196
Old 07-19-2018, 10:28 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
Check the control cables.
Take the trany control cable off and then shift into forward with both the cable and the lever on the side of the trany. See if the cable position is correct when both the control lever and trany lever are in forward.
When you are "messing' with the carburetor you are probably moving the control cable not the throttle butterfly.
Most of the time problems like this happen because the ends of the cable are not fixed down securely.*

TRUE GRIT

*Edit: Make that the ends of the outer cover not being fixed down securely.

Last edited by JOHN COOKSON; 07-19-2018 at 10:58 AM.
Reply With Quote
  #8   IP: 137.200.0.112
Old 07-19-2018, 11:15 AM
joe_db's Avatar
joe_db joe_db is online now
Afourian MVP
 
Join Date: May 2009
Posts: 4,474
Thanks: 49
Thanked 1,026 Times in 721 Posts
If the clamp that holds the cable onto the carb gets loose, the outer jacket can move instead of the inner cable that moves the throttle plate. Something to check
No that this happened to me.......that you know of
Reply With Quote
  #9   IP: 174.213.3.69
Old 07-19-2018, 07:02 PM
Fstued's Avatar
Fstued Fstued is offline
Senior Member
 
Join Date: Jan 2014
Location: Ocean Beach
Posts: 65
Thanks: 27
Thanked 0 Times in 0 Posts
Thanks for all the suggestions

I tightened the forward gear 2 notches and it seemed to do the trick. But I am concerned that the stuffing gland nut may be a touch to tight it was awfully warm down there after my test motor. It didn't seem to be dripping at all. So I think I'll give it a slight turn just a few degrees and see if I can get sa drip a minute or less
Thanks for all the help
Stu
Reply With Quote
  #10   IP: 72.194.219.196
Old 07-19-2018, 08:19 PM
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
It is important that the packing not be so tight that it generates so much heat that the shaft becomes scored. The packing gland should run at the same temp as the surrounding water.

TRUE GRIT
Reply With Quote
  #11   IP: 24.152.132.140
Old 07-20-2018, 12:45 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
Quote:
Originally Posted by joe_db View Post
Have you got a helper, taken the flame arrestor off, and figured out if there is an actual mechanical issue with the throttle plate not moving correctly?
Quote:
Originally Posted by Fstued View Post
I'll also remove the flame arrestor and check the carb throttle and make sure the linkage is working properly on the mechanical workings in the carburetor. I really don't want to remove the carb.
You can see the throttle butterfly by removing the flame arrestor? I don't know how. The choke, yes but not the throttle.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others
Reply With Quote
  #12   IP: 137.200.32.54
Old 07-20-2018, 06:22 AM
joe_db's Avatar
joe_db joe_db is online now
Afourian MVP
 
Join Date: May 2009
Posts: 4,474
Thanks: 49
Thanked 1,026 Times in 721 Posts
D'oh! Of course you are right. You need to unbolt the carb and let it drop a few inches. The view is in from the top
Reply With Quote
  #13   IP: 207.164.83.34
Old 07-20-2018, 08:47 AM
Bratina Bratina is offline
Senior Member
 
Join Date: Jun 2015
Location: Toronto, Ontario
Posts: 96
Thanks: 126
Thanked 26 Times in 17 Posts
These two items point firmly to the packing gland binding up due to being massively over-tightened. Loosen it up substantially until it's dripping a few times a minute, then test the engine. If the symptoms go away then we've found our smoking gun.

Quote:
Originally Posted by Fstued View Post
Then in a bit the RPMs will kick in.


I tightened the forward gear 2 notches and it seemed to do the trick. But I am concerned that the stuffing gland nut may be a touch to tight it was awfully warm down there after my test motor. It didn't seem to be dripping at all.
Reply With Quote
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 idea not a problem. CajunSpike Fuel System 6 02-27-2018 02:19 PM
Palmer and A4 Carb Problem keelbolts Fuel System 7 10-30-2016 07:31 PM
Carb and/or Fuel Pump Problem jfo99 Troubleshooting 4 07-23-2012 11:58 AM
Carb Problem newporttom Fuel System 3 07-13-2007 04:41 PM
Carb problem? cat30 Fuel System 3 10-30-2006 05:30 PM


All times are GMT -4. The time now is 11:03 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