yanmar vibration at low rpm - SailNet Community
 
LinkBack Thread Tools
post #1 of 3 Old 02-26-2014 Thread Starter
Junior Member
 
Join Date: Feb 2014
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
yanmar vibration at low rpm

my mechanics have run out of idea's and i'm running out of money…

my '96 100hp yanmar diesel, 4JH2H-UTE vibrates….only in forward gear, only after reaching operating temp, and only between 700-800 rpm's. as perplexing as that is, listen to this.. once the shaking (which is not violent) begins, it will usually just stop within a minute or so even though nothing else has changed including the rpms. this condition has been around for 7-years and has never gotten worse or better. it is a nuisance to me, but apparently a big deal to a possible buyer.

here's what's been tried:
1. acqua drive /cv joint rebuilt
2. transmission pulled/inspected..meets specs
3. timing advanced/retarded..no change
4. fuel files/lines inspected..all clear
5. injectors checked
6. fuel filter leading to injector pump bypassed..no change

HELP
17spyglass17 is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 3 Old 02-26-2014
Senior Member
 
night0wl's Avatar
 
Join Date: Mar 2006
Location: Fort Lauderdale
Posts: 1,459
Thanks: 0
Thanked 21 Times in 21 Posts
Rep Power: 10
 
Re: yanmar vibration at low rpm

Check your motor mounts...my boat had a nasty harmonic vibration between 2100 and 2300 RPM. Turned out that one of the mounts was bad.

S/V Jendai
Beneteau 343
night0wl is offline  
Quote Quick Reply Share with Facebook
post #3 of 3 Old 03-04-2014
Junior Member
 
Join Date: Dec 2012
Location: Vancouver BC
Posts: 17
Thanks: 0
Thanked 3 Times in 3 Posts
Rep Power: 0
 
Re: yanmar vibration at low rpm

In considering your dilemma, some things to note. The relationship between fuel delivery and load in forward and reverse are different and therefore the conditions are not matched at the same rpm, so the question is, what occurrences are there which could cause your problem which also correct themselves? Considering that the VE pump is the one component which is constantly transitioning itself between springs, hydraulic pressures and centrifugal forces, all of which are much more likely to show their flaw at lower rpms, my money is on your fuel pump. Pump characteristics change as they warm up and sometimes they change for the better, and sometimes not. My advice would be to have the pump removed and tested/reclalibrated specifying that you have this problem. Any fuel tech worth his 10 coffees will be able to sort this out for you.
Ahoyhoy is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Vibration starts at 2000 rpm Dave_E Diesel 8 10-27-2013 08:25 PM
Yanmar tach reads low rpm malyea Gear & Maintenance 11 06-05-2013 08:38 AM
Volvo MD5B vibration. RPM sweet spot? itsaboat Diesel 1 03-29-2013 11:56 AM
Yanmar stalls at low rpm markgoldfarb Diesel 2 06-26-2011 09:48 AM
Engine vibration between 1100-1200 RPM - Normal? zAr Gear & Maintenance 8 07-04-2009 12:49 AM

Posting Rules  
You may post new threads
You may 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 On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome