Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 05-09-2017, 13:06   #16
Registered User
 
theway's Avatar

Join Date: Sep 2010
Location: San Francisco, CA
Boat: 1980 Pearson 323 - 34ft LOA
Posts: 532
Re: Engine More Quite At Same RPMs?

Quote:
Originally Posted by ontherocks83 View Post
The exhaust mixing elbow could still be a problem too. A restricted exhaust can cause just as much power loss as restricted fuel. You're going to have to go through each item one by one until you get it resolved. Just make sure you are thorough and don't necessarily stop when you find one thing, Just because you find a dirty fuel filter doesn't mean there isn't something else also, multiple "neglected" things can stack up and cause all sorts of havoc.


I'm a little hesitant to tackle the elbow here in Fiji, or in Vanuatu. I'm planning to be in Australia after that in October... seems like a better place to start taking that apart and/or get a new one. I'll see what's available in port denarau and maybe set aside a day or two if it feels right.
__________________

theway is offline   Reply With Quote
Old 05-09-2017, 14:04   #17
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,401
Re: Engine More Quite At Same RPMs?

Have you rechecked the gearbox oil yet ?

Black smoke could mean you've lost gearbox oil through the the heat exchanger.
__________________

DumnMad is offline   Reply With Quote
Old 05-09-2017, 14:54   #18
Registered User
 
theway's Avatar

Join Date: Sep 2010
Location: San Francisco, CA
Boat: 1980 Pearson 323 - 34ft LOA
Posts: 532
Re: Engine More Quite At Same RPMs?

Quote:
Originally Posted by DumnMad View Post
Have you rechecked the gearbox oil yet ?

Black smoke could mean you've lost gearbox oil through the the heat exchanger.


How is the gearbox oil related to exhaust?

I checked it a couple weeks ago, but I'll look again...

The black smoke was only a few moments on the start up after the stall. My guess is that was everything that was unburnt durning the stall.
theway is offline   Reply With Quote
Old 05-09-2017, 14:59   #19
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,401
Re: Engine More Quite At Same RPMs?

Quote:
Originally Posted by theway View Post
How is the gearbox oil related to exhaust?

I checked it a couple weeks ago, but I'll look again...

The black smoke was only a few moments on the start up after the stall. My guess is that was everything that was unburnt durning the stall.
Weird I know, but it happened to me. Oil sucked through a pinhole in the heat-exchanger.
DumnMad is offline   Reply With Quote
Old 07-09-2017, 14:18   #20
Registered User
 
jhulmer's Avatar

Join Date: Aug 2014
Location: Biloxi, MS
Boat: 1978 Cabo Rico Tiburon 36
Posts: 317
Re: Engine More Quite At Same RPMs?

theway,
I had this happen to me on a 2gm20 turned out to be a reduced ID/clogged exhaust hose. Over the years the salt/calcium (rock hard crap) built up on the walls of the hose and I was getting a lot of back pressure.

This happened slowly over time so I didn't notice it. Man! was I happy when I replaced the hose and had a lot more power!

worth checking
jhulmer is online now   Reply With Quote
Old 07-09-2017, 14:28   #21
Registered User
 
theway's Avatar

Join Date: Sep 2010
Location: San Francisco, CA
Boat: 1980 Pearson 323 - 34ft LOA
Posts: 532
Re: Engine More Quite At Same RPMs?

Quote:
Originally Posted by jhulmer View Post
theway,
I had this happen to me on a 2gm20 turned out to be a reduced ID/clogged exhaust hose. Over the years the salt/calcium (rock hard crap) built up on the walls of the hose and I was getting a lot of back pressure.

This happened slowly over time so I didn't notice it. Man! was I happy when I replaced the hose and had a lot more power!

worth checking


What is "ID"?

Yeah, this seems to be a likely possibility. I'm going to have a look at the exhaust system at the next decent port.

Thanks for sharing.
theway is offline   Reply With Quote
Old 07-09-2017, 15:01   #22
Registered User
 
jhulmer's Avatar

Join Date: Aug 2014
Location: Biloxi, MS
Boat: 1978 Cabo Rico Tiburon 36
Posts: 317
Re: Engine More Quite At Same RPMs?

Quote:
Originally Posted by theway View Post
What is "ID"?

Yeah, this seems to be a likely possibility. I'm going to have a look at the exhaust system at the next decent port.

Thanks for sharing.
oops sorry - ID" inside diameter
jhulmer is online now   Reply With Quote
Old 03-12-2017, 13:09   #23
Registered User
 
theway's Avatar

Join Date: Sep 2010
Location: San Francisco, CA
Boat: 1980 Pearson 323 - 34ft LOA
Posts: 532
Re: Engine More Quite At Same RPMs?

Update:
I replaced the exhaust elbow, clean injectors and replaced the air element in Bundaberg.

Two things to note.

First is a question/observation. Iím getting a lot more exhaust fumes in the cockpit. My guess is that with the new elbow they are more freely exiting the engine and therefore more of them...?

Second, while taking off the elbow I noticed how loose it was. Which was creating an exhaust leak. This was the main culprit in clogging my air element. So my semi conclusion to the initial problem stated seems to be restricted aspiration, both air coming in and exhaust flowing out.

(Anyone tips on how to tighten the coupling between the elbow and the riser when the plumbing is on a specific side with those trick reverse threads... getting a big enough wrench is on my list. )
__________________

theway is offline   Reply With Quote
Reply

Tags
engine, rpm

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Jabsco quite flush or Need a quite bog Beccara Plumbing Systems and Fixtures 5 23-03-2015 21:41
Same Chemistry, Same Age, Different AH Thin Line Electrical: Batteries, Generators & Solar 13 23-02-2015 07:28
Same old, same old in the polar regions knottybuoyz Polar Regions 4 07-03-2008 17:44



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 20:24.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.