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: 64.163.88.18
Old 02-11-2013, 05:09 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Loud "clicking" at higher RPMs

Hey All,

Last year I swapped out my old Atomic 4 for a rebuilt one. I got it from a reputable mechanic in Northern California....

I'm fairly familiar with these engines (have done a lot of tinkering and I taking on most repairs with help from Moyer Marine and the internet over the past 10 years)...I was hoping to get some feedback about my current symptoms before going down the rabbit hole of running thru every possibility I find on Google.

Currently, she starts like a champ every time (requires little choke), the idle RPM adjust is set to standard, the plugs/wires/coil are like new, the electronic ignition is fairly new, the timing (not 100% sure...I set it for the first time) is good, gas is fresh, carb is new, exhaust and raw water seem normal.

Well...when I run her at higher RPMs (i.e. wind dies and we motor a few miles back to our marina), she'll at some point sputter, lose power and a LOUD clacking (electrical spark sounding) noise then will almost die and then I need to back her down to a low RPM and she is fine again. But I feel like she's limping a little. This is hard to replicate because it seems to only happen after awhile under load at higher RPMs.

The most suspect aspect of the boat is the DC wiring. Before I rewire the DC circuit, I'd like to have a really good reason as this seems very time consuming.

Any thoughts?

Thanks in advance...
Reply With Quote
  #2   IP: 107.0.6.242
Old 02-11-2013, 05:31 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

Mixture may be getting lean after hard running. Look at fuel tank vent for possible blockage. Check fuel pressure at carb while at cruise rpm. I have had similar experience. Also, pcv can lean out mixture at high rpm.
Reply With Quote
  #3   IP: 76.7.144.132
Old 02-11-2013, 06:16 PM
Marian Claire's Avatar
Marian Claire Marian Claire is offline
Afourian MVP
 
Join Date: Aug 2007
Posts: 1,797
Thanks: 33
Thanked 129 Times in 94 Posts
Do you have an electric fuel pump? Dan S/V Marian Claire
Reply With Quote
  #4   IP: 99.141.136.1
Old 02-11-2013, 06:32 PM
jbsoukup's Avatar
jbsoukup jbsoukup is offline
Afourian MVP
 
Join Date: Jan 2012
Location: chicago
Posts: 148
Thanks: 0
Thanked 12 Times in 9 Posts
ignition coil?
Reply With Quote
  #5   IP: 64.163.88.18
Old 02-11-2013, 06:59 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by hanleyclifford View Post
Mixture may be getting lean after hard running. Look at fuel tank vent for possible blockage. Check fuel pressure at carb while at cruise rpm. I have had similar experience. Also, pcv can lean out mixture at high rpm.
Looks like I'm about to learn some new stuff...I've never checked my fuel tank vent. Is it as easy as a visual or is there something else to consider?

How does one normally check the fuel pressure at carb while at cruise rpm?

Also, can you expand on "pcv can lean out mixture at high rpm"? I have no experience with the pcv.

thanks!
Reply With Quote
  #6   IP: 64.163.88.18
Old 02-11-2013, 06:59 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by Marian Claire View Post
Do you have an electric fuel pump? Dan S/V Marian Claire
nope, the original pump.
Reply With Quote
  #7   IP: 64.163.88.18
Old 02-11-2013, 07:02 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by jbsoukup View Post
ignition coil?
the ignition coil is about a year old.

the issue would seem to be electrical. there is a loud misfiring racket when it happens. sound like throwing some screws into a fan..then it loses power until i power down and then it runs fine at low RPMs.

Last edited by kevin d; 02-11-2013 at 07:20 PM.
Reply With Quote
  #8   IP: 76.7.144.132
Old 02-11-2013, 07:52 PM
Marian Claire's Avatar
Marian Claire Marian Claire is offline
Afourian MVP
 
Join Date: Aug 2007
Posts: 1,797
Thanks: 33
Thanked 129 Times in 94 Posts
Good deal. That eliminates the electric pump stuck ball "clacking" noise possibility. Another long shot but it ties in with the lean condition Hanley mentions. http://www.moyermarine.com//forums/s...ead.php?t=3369 So maybe try closing the choke some when it starts to stall. If that does not help at what RPM does this happen? Advance weights sticking?
Dan S/V Marian Claire
Reply With Quote
  #9   IP: 173.166.26.241
Old 02-11-2013, 07:56 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

Fuel pressure can be monitored right at the carb using one of these. http://www.mcmaster.com/#atmospheric...gauges/=lfs4fa This can save a lot of diagnostic grief in the long run.
Reply With Quote
  #10   IP: 65.92.161.249
Old 02-11-2013, 08:06 PM
Sony2000 Sony2000 is offline
 
Join Date: Dec 2011
Location: Montreal, QC. Canada
Posts: 424
Thanks: 0
Thanked 0 Times in 0 Posts
It sounds like fuel starvation, brought about by vapor lock, or a restriction to the flow, prior to the fuel/water separator.
Reply With Quote
  #11   IP: 24.152.131.153
Old 02-11-2013, 08:45 PM
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
Reading the description my first thought was as Dan mentioned at the end of his post, faulty timing advance mechanism:
  • It's affected by RPM.
  • Malfunction affects performance.
  • Depending on the nature of the malfunction, it could be the source of the noise.
  • Mix them all together and it fits the symptoms.
__________________
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: 199.168.148.136
Old 02-12-2013, 11:58 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
It Could Be This

Electricity jumping between the spark plug wires. After the engine is run for a while the insulation could be breaking down and electricity is jumping between plug wires and a plug(s) are firing at the wrong time which results in a knock or a hellish engine sound.
Are you running graphite core or solid core wires? In my experience graphite core spark plug wires aren't worth a crap on a boat.
Also have you checked for tracking or arcing between the terminals inside the distributor cap?

TRUE GRIT

Edit: Kevin: When I read about arcing, sparking, and "loud clacking, electrical spark sounding", as reported in your post #1, I think of something after the coil not the 12 volt circut.

Last edited by JOHN COOKSON; 02-12-2013 at 12:58 PM.
Reply With Quote
  #13   IP: 128.183.140.38
Old 02-12-2013, 12:16 PM
edwardc's Avatar
edwardc edwardc is offline
Afourian MVP
 
Join Date: Aug 2009
Location: Laurel, MD
Posts: 2,509
Thanks: 153
Thanked 595 Times in 388 Posts
My first two thoughts were :

- Sticking valve
- Distributor advance weights
__________________
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4

Reply With Quote
  #14   IP: 98.248.12.160
Old 02-12-2013, 01:54 PM
tartansailboat tartansailboat is offline
Senior Member
 
Join Date: Mar 2009
Posts: 100
Thanks: 0
Thanked 2 Times in 2 Posts
fuel pressure gauge

Hanley, there are so many pressure gauges listed in the McMaster link, could you be more specific and tell me which one you used? Also, is this gauge plumbed into the fuel line with a tee as would be for a gas pressure gauge? Or in line, like a flow meter gauge? Did you mount your gauge on the output of the fuel pump, or on the input to the carb or in the middle of the fuel line (rubber or copper line)?

Thanks, Herb
Reply With Quote
  #15   IP: 64.163.88.18
Old 02-12-2013, 01:57 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by JOHN COOKSON View Post
Electricity jumping between the spark plug wires. After the engine is run for a while the insulation could be breaking down and electricity is jumping between plug wires and a plug(s) are firing at the wrong time which results in a knock or a hellish engine sound.
Are you running graphite core or solid core wires? In my experience graphite core spark plug wires aren't worth a crap on a boat.
Also have you checked for tracking or arcing between the terminals inside the distributor cap?

TRUE GRIT

Edit: Kevin: When I read about arcing, sparking, and "loud clacking, electrical spark sounding", as reported in your post #1, I think of something after the coil not the 12 volt circut.
Thanks....I've got a spare coil/set of wires. I'll swap them out and take a look at the distributor cap (and timing) and see if the problem goes away.
Reply With Quote
  #16   IP: 64.163.88.18
Old 02-12-2013, 02:00 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quote:
Originally Posted by edwardc View Post
My first two thoughts were :

- Sticking valve
- Distributor advance weights
Thanks Ed, would MMO help with the sticking valve if that is the case? Also, I'm not very familiar with the distributor advance weights. What should I be looking for? Or how would I isolate the issue to them?
Reply With Quote
  #17   IP: 64.163.88.18
Old 02-12-2013, 02:15 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Quick questions...

Can someone describe the easiest way to set the ignition timing?

And what is the best way to check if the mechanical fuel pump is working properly?

Thanks
Reply With Quote
  #18   IP: 128.183.140.38
Old 02-12-2013, 02:20 PM
edwardc's Avatar
edwardc edwardc is offline
Afourian MVP
 
Join Date: Aug 2009
Location: Laurel, MD
Posts: 2,509
Thanks: 153
Thanked 595 Times in 388 Posts
Yes, some MMO in the oil (up to one quart!) and some MMO squirted into each cylinder after each use (or as often as possible) so it can soak between uses is the usual course of treatment for a stuck/sticky valve.

The advance weights and the springs that control them are located in the distributor, underneath the breaker plate. If they get stuck out, that would result in excessive advance which could cause "pinging" and poor running.
Easiest way to evaluate them is to just open the distributor and remove the breaker plate and examine them for smooth operation and no broken springs.
__________________
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4

Reply With Quote
  #19   IP: 76.7.144.132
Old 02-12-2013, 03:25 PM
Marian Claire's Avatar
Marian Claire Marian Claire is offline
Afourian MVP
 
Join Date: Aug 2007
Posts: 1,797
Thanks: 33
Thanked 129 Times in 94 Posts
This may answer your timing question. http://www.moyermarine.com/forums/sh...ghlight=timing Dan S/V Marian Claire
Reply With Quote
  #20   IP: 64.163.88.18
Old 02-12-2013, 04:25 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
Thanks Dan and Ed!
Reply With Quote
  #21   IP: 107.0.6.242
Old 02-12-2013, 06:34 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
Quote:
Originally Posted by tartansailboat View Post
Hanley, there are so many pressure gauges listed in the McMaster link, could you be more specific and tell me which one you used? Also, is this gauge plumbed into the fuel line with a tee as would be for a gas pressure gauge? Or in line, like a flow meter gauge? Did you mount your gauge on the output of the fuel pump, or on the input to the carb or in the middle of the fuel line (rubber or copper line)?

Thanks, Herb
Right at the "G" spot:

Last edited by hanleyclifford; 07-13-2016 at 08:32 PM.
Reply With Quote
Old 02-12-2013, 06:39 PM
hanleyclifford
This message has been deleted by hanleyclifford.
  #22   IP: 68.5.194.131
Old 02-13-2013, 12:05 AM
seabreeone seabreeone is offline
Member
 
Join Date: Sep 2011
Location: DANA POINT CA.
Posts: 3
Thanks: 0
Thanked 0 Times in 0 Posts
Clicking

I had an issue like this last year. I tried everything. It turned out to be #4 valve would stick at high RPM'S, At low R's it would free up. I had just the right amount of carbon and varnish on the stem to hang it up.I had to remove the head reem the guide and then I put in the after market valve springs. They are taller and stiffer.Runs well now
Reply With Quote
  #23   IP: 65.92.161.249
Old 02-13-2013, 09:25 AM
Sony2000 Sony2000 is offline
 
Join Date: Dec 2011
Location: Montreal, QC. Canada
Posts: 424
Thanks: 0
Thanked 0 Times in 0 Posts
I fully agree with seabreeone, but if the power loss is greater than just running on three cylinders, then I would look for fuel starvation.
Reply With Quote
  #24   IP: 107.0.6.242
Old 02-13-2013, 12:10 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

Whenever a problem like this develops the first thing I do is check the basics: timing, both initial and centrifugal, dwell (even with EI), compression (though such test may not detect weak valve spring), cleanliness and viscosity of oil and engine running temp (both of which can influence valve guides) and valve lifter clearances. Before going too far afield make sure the above are on spec. Because I believe in continuous diagnosis I have added fuel pressure gauge and air/fuel ratio gauges. If things are not allowed to go off spec problems are rare.
Reply With Quote
  #25   IP: 64.163.88.18
Old 02-14-2013, 03:08 PM
kevin d kevin d is offline
Senior Member
 
Join Date: May 2007
Posts: 11
Thanks: 0
Thanked 0 Times in 0 Posts
I think the first thing I'm going to do is rule out 'electrical' issues.

I'm planning to check timing, coil, spark plugs/wires, quick inspection of DC wiring, etc.

I may do an oil change, recheck the idle mixture and will inspect the fuel lines and gas tank vent.

Thanks for all your help....any other quick (do first) suggestions would be much appreciated.

Cheers!
Reply With Quote
Reply

Tags
atomic 4

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
carburetor Problems - HIGH RPMs jakecolumbia8.3 Fuel System 10 10-10-2011 08:58 PM
Prop shaft alignment or a problem with the crank? Knock at low RPM's rshearley Reversing Gear 2 05-30-2011 07:48 AM
Loss of Power at Higher RPMs. Greg Kingman Troubleshooting 3 08-24-2009 04:43 PM
Atomic 4 Engine RPMs sailingdude General Interest 2 08-09-2007 06:59 PM
Low RPM's Under Load Jeremy Thompson Troubleshooting 7 11-18-2005 06:10 PM


All times are GMT -4. The time now is 02:55 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