Yanmar 3YM30 Alternator Belt - SailNet Community
Reply
 
LinkBack Thread Tools
post #1 of 14 Old 01-10-2008 Thread Starter
Junior Member
 
Join Date: Feb 2002
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
Yanmar 3YM30 Alternator Belt

When recently replacing the alternator belt on my Yanmar 3YM30 (80 amp alternator) with the same belt that was supplied with the engine new (A 37.5), I had to remove the fresh water pump pulley to fit the belt. The alternator would not swing down far enough to slip the belt over the three pulleys. Yanmar assures me this is the correct belt, but it seems strange to have to change it this way? Anyone else have this problem?
cyphert is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #2 of 14 Old 01-10-2008
Moderator
 
JohnRPollard's Avatar
 
Join Date: Mar 2007
Location: Chesapeake
Posts: 5,680
Thanks: 0
Thanked 4 Times in 3 Posts
Rep Power: 10
     
This doesn't sound right. On our 3GM30 engine, it is not necessary to remove the pulley on the fresh water/coolant pump to replace the belt. There is enough throw on the alternator adjustment bracket to slacken the belt completely. Hmmm.

On the other hand, it sounds like you have a higher amp alternator than standard. Maybe the case is larger, preventing you from getting all the throw from the adjustment bracket. But I haven't heard of folks that have upgraded to larger alternators complaining about this problem.

You might try another brand of belt and see if it makes a difference. I would order some Gates Green Stripe belts, which wear better with the high-output alternators anyway. Good luck!

P.S. I see this is your first post. Welcome aboard!
JohnRPollard is offline  
Quote Quick Reply Share with Facebook
post #3 of 14 Old 01-11-2008
Senior Member
 
Join Date: Jan 2007
Location: New Jersey
Posts: 126
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 9
 
Try calling Mack Boring there a Yanmar distributer 1800 622 5364. Maybe they can put you in the right direction.

Haverstraw Bay, Hudson River N.Y.
Beneteau 32.1 OCEANIS
tonic is offline  
Quote Quick Reply Share with Facebook
post #4 of 14 Old 11-22-2008
Senior Member
 
CrazyRu's Avatar
 
Join Date: May 2007
Posts: 452
Thanks: 2
Thanked 0 Times in 0 Posts
Rep Power: 9
 
NAPA automotive stores have all sort of belts normally for a price lower that Yanmars. The belts made with about half an inch increment, you can buy next size or two sizes bigger.
CrazyRu is offline  
Quote Quick Reply Share with Facebook
post #5 of 14 Old 11-22-2008
Senior Member
 
Join Date: Sep 2006
Location: Scotland
Posts: 2,364
Thanks: 0
Thanked 11 Times in 11 Posts
Rep Power: 9
 
Sometimes if you loosen the alternator mounting bolts, or take them off so that you can rock the alternator a wee bit, you can get the belt over the alternator puller that way.
Rockter is offline  
Quote Quick Reply Share with Facebook
post #6 of 14 Old 11-22-2008
Senior Member
 
Join Date: Dec 2007
Posts: 201
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 8
 
Make sure you loosen the pivot bolt and the swing arm bolt. Sometimes, loosening only the swing arm bolt will not give the full range of motion.
jason3317 is offline  
Quote Quick Reply Share with Facebook
post #7 of 14 Old 08-20-2009
Junior Member
 
Join Date: Aug 2009
Posts: 1
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
In your messgae you say "The alternator would not swing down far enough to slip the belt over the three pulleys".
I my 3ym30 I need to use two v-belt, one for the alternator (25131-003000) and another one for the water pump (104511-78780). There is 2 pulley on the crank shaft. May be this could kelp. Good luck,
pierre70 is offline  
Quote Quick Reply Share with Facebook
post #8 of 14 Old 08-20-2009
Senior Member
 
Join Date: Jul 2007
Posts: 408
Thanks: 0
Thanked 6 Times in 4 Posts
Rep Power: 9
 
Yanmar belts

My 3GM30 has 3 belts. the inner one is the raw water pump, the next is the water pump and alternator and the outer one is for a Sea-frost compressor.



On mine I have to remove the compressor pulley to take that belt off as the compressor does not rotate much. But the alternator has plenty of swing on its bracket.

CapnRon47 is offline  
Quote Quick Reply Share with Facebook
post #9 of 14 Old 01-19-2012
Junior Member
 
Join Date: Jun 2007
Posts: 26
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
 
How can I find the Gates equivalent fan belt for my Yanmar 4JH2E? I'm going through fan belts fast because my 80 amp alternator is not aligned exactly with the belt. I need the toughest belts I can get until I can get a better alignment.

Caliber 40 Bahamas bound
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
sorcerer33 is offline  
Quote Quick Reply Share with Facebook
post #10 of 14 Old 01-19-2012
Member
 
Join Date: May 2008
Posts: 44
Thanks: 0
Thanked 1 Time in 1 Post
Rep Power: 0
 
Belt alignment trick

A thought on your alignment- A good old trick is to lay a dowel rod into the groove of the pulley. It will find it's own center and give an easy perfect progression of where the pulley is really pointed. This makes it easy to decide on the next step. If that does not help they also make flat belts that replacement the V belt. You can do a search for Yanmar serpentine alternator pulley kit.

Good luck

Scott

Disclosure: Yachtwork is a marine vendor
yachtwork 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
Need help YANMAR engine mount Giulietta Gear & Maintenance 20 04-15-2010 01:15 PM
Yanmar 4JH2E air filter element garyroot Gear & Maintenance 8 03-30-2010 08:23 PM
ATF or SAE ? Yanmar 4JH2E / Trans: KM4A TAK Gear & Maintenance 4 11-05-2007 10:34 PM
Yanmar with aftermarket tach and temp guage Northeaster Gear & Maintenance 12 08-07-2007 08:40 PM
Prop for Morgan OI w/ Yanmar 3GM30F cwarwick Gear & Maintenance 1 11-16-2004 01:17 PM

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