SailNet Community - Reply to Topic

   Search Sailnet:

 forums  store  


Quick Menu
Forums           
Articles          
Galleries        
Boat Reviews  
Classifieds     
Search SailNet 
Boat Search (new)

Shop the
SailNet Store
Anchor Locker
Boatbuilding & Repair
Charts
Clothing
Electrical
Electronics
Engine
Hatches and Portlights
Interior And Galley
Maintenance
Marine Electronics
Navigation
Other Items
Plumbing and Pumps
Rigging
Safety
Sailing Hardware
Trailer & Watersports
Clearance Items

Advertise Here






Go Back   SailNet Community > On Board > Gear & Maintenance > Yanmar rev counter
 Not a Member? 


Thread: Yanmar rev counter Reply to Thread
Title:
  

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

Message:
Trackback:
Send Trackbacks to (Separate multiple URLs with spaces) :
Post Icons
You may choose an icon for your message from the following list:
 

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:

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.



Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Additional Options
Miscellaneous Options

Click here to view the posting rules you are bound to when clicking the
'Submit Reply' button below


Topic Review (Newest First)
06-26-2008 04:29 AM
t.tilley
It's the number of poles in the alternator plus...

The way that the "diesel tachs" that run off the alternator work is based primarily on the number of poles that are in the tach - usually 12. A lot - but not all - of these tachs have one or two rotary switches on the back; typically on is for selecting the number of poles since not all alternators have 12 poles. The other rotary switch is for selecting the pulley ratio. Sometimes both functions are in a single switch. Calibration is done either by having another tach (mechanical tach for example) hooked up and then trying different switch settings to get it to register close to the "mechanical" tach; alternatively use a "guesstimate" method - if your diesel idles at 800rpm according to spec, adjust the tach so it shows 800rpm, if peak speed at spec if 3200 rpm - go to WOT and see if tach is close to 3200rpm.

Learned about this the hardway installing a tach on my little Universal diesel. Good luck, I hope that this helps.

TomT
06-26-2008 02:31 AM
Omatako Hey, thanks for that. I would prefer an analogue type simply because digital stuff makes you have to look at it and sort of makes peripheral vision redundant.

But I'll follow this through as a viable alternative.

Thanks
Andre
06-25-2008 10:01 AM
arf145 One possibility for mortals would be the Tiny-Tach diesel tach:

Tiny-Tach: Diesel Tachometers

I have no personal experience with it, sorry to say.
06-25-2008 07:17 AM
Omatako OK, so I finally determined that the tacho itself is toast. Now the question is where to from here. The Yanmar replacement costs around $300 and frankly, I don't need to know the RPM that badly.

What pearls of wisdom are out there regarding non-genuine rev counters? I suspect it will be real hard to find another one that runs off the same Yanmar sensor.

I recall in my youth working with gasoline engines, rev counters could be bought that ran off the back of the alternator and my thinking is that this should work irrespective of the fuel type.

My question (probably rhetorical) is how does the rev counter know what the ratio is of alt RPM relative to engine RPM? I have a very accurate analog tacho that I can run off the crank pulley to determine the real engine RPM but if it's different to the alt RPM (and I can only assume it will be), how does it get corrected?

Or is there a better idea altogether that mere mortals like me can afford?

Andre
05-27-2008 04:04 AM
Omatako
Quote:
Originally Posted by boydgatlin View Post
When the tach on my Yanmar 4JH3E quit, I found the problem to be nothing more serious than a bit of corrosion on the wire disconnects at the sensor. A bit of cleaning restored full functionality.
I've been down that track and no success but thanks for the tip.

The next problem is that the body of the sensor is badly rusted (one would think these things would be salt-water-resistant) and I'm not keen on trying to move if unless I know I need to.

Andre
05-26-2008 08:29 AM
boydgatlin When the tach on my Yanmar 4JH3E quit, I found the problem to be nothing more serious than a bit of corrosion on the wire disconnects at the sensor. A bit of cleaning restored full functionality.
05-26-2008 06:07 AM
Omatako
Yanmar rev counter

Does anyone have any info on the resistance of a rev counter flywheel sensor on a Yanmar 4JH series engine?

My tacho stopped working and I read in a manual that the sensor's internal resisteance should check in at 1.6 kilo-ohms. Mine measures 1.2.

I just wondered how sensitive these things are. I suspect my tacho is toast but want to cover all the bases before spending unnecessary bucks on a new tacho.

Andre

 
Posting Rules
You may post new threads
You may post replies
You may post attachments
You may edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On


All times are GMT -4. The time now is 05:27 AM.

Add to My Yahoo!         
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.1
(c) Marine.com LLC 2000-2012

The SailNet.com store is owned and operated by a company independent of the SailNet.com forum. You are now leaving the SailNet forum. Click OK to continue or Cancel to return to the SailNet forum.