FJowners.com

General Category => Maintenance => Topic started by: twangin4u on May 31, 2015, 06:37:14 AM

Title: Speedometer/ odometer
Post by: twangin4u on May 31, 2015, 06:37:14 AM
84 fj1100. S

Question for the folks.. My speedo is about 5 mph off. Too fast. Anyone know if it can be adjusted? Just turned over 60k miles today. Then I got to thinking.. No.. Probably more like 56500. I watch the mileage markers on the hiway and my odometer goes about 1 mile + 1/4 of a 1/10th. Pretty sure tires are correct size. They were new when I bought it and still are.
Thanks
Title: Re: Speedometer/ odometer
Post by: charleygofast on May 31, 2015, 08:01:00 AM
My '84 speedo is 3-5 mph off above 60. I dont think there is a way to adjust it...but I could be wrong...anyone??? Your front tyre should be a 120/80-16. I never gave a thought to the odo. reading, until now hmmm...40,000 plus how much more.                                                                                                          Cheers!                                                                                                                                                                                                                Charley.
Title: Re: Speedometer/ odometer
Post by: aviationfred on May 31, 2015, 09:03:45 AM
3-5 mph difference at 60+mph is pretty normal. Nothing to be concerned about.

The only thing I can think about for the odometer is with tire/wheel size. OEM sizes are 120/80/16 and the rear is a 150/80/16.

Fred
Title: Re: Speedometer/ odometer
Post by: Bill_Rockoff on May 31, 2015, 09:14:48 AM
All Japanese bike speedometers from the 1970's through most of the 2000s are "batshit crazy."  It is frequently a percentage of error, with maybe a little fixed error.  10% off is typical.  So, your speedo is probably 5 mph off at 60 mph, and it is probably closer to 10 mph off at 120 mph.  If Yamaha knew yours was reading only 5 mph fast at normal traffic highway speeds, they would probably take it back under warranty even  now, 30 years later, and adjust it so that it's even worse, just like all the normal ones.  "So sorry, speedometer reads 60 mph at 54 now, not 55."

The odometer - 1/4 of 1/10th is 1/40th of a mile - that's 2.5% off you're talking about, 132 feet over the course of a mile.  That's the difference between being in the right or left lane when your highway curves, or taking a second to notice exactly where the odometer is when you pass a mile marker.  More likely, that's the difference between a new tire and a tire with 1/4" worn off the tread.  

Tuesday:  "Hooray, my gear is strapped to my FJ, I have brand new tires and fresh oil, and my odometer is exactly right!  Time to head to the FJ rally!"
Sunday: "Crap, my head hurts, my pants don't fit, I'm dirty and tired and everything smells like smoke, and my FJ odometer is 1/40th of a mile off again for every mile.  I can't wait until the next FJ rally."
Title: Re: Speedometer/ odometer
Post by: twangin4u on May 31, 2015, 10:18:48 AM
Well.. I didn't want to tear into the cluster only to find that I wasted my time. Which is why I threw it out there. I guess to make a positive outta a negative.. The 5 mph sorta gives me the false idea that I'm traveling a bit faster than I am. Hopeful
Keep me closer to the posted speed limit. Less citations
Title: Re: Speedometer/ odometer
Post by: krusty on May 31, 2015, 08:03:38 PM
Do you have or can you borrow a GPSr? Secure (tape) it somewhere near your dash and go for a ride and compare readings at various speeds, say, common speed limits.
Title: Re: Speedometer/ odometer
Post by: twangin4u on May 31, 2015, 08:17:11 PM
Quote from: krusty on May 31, 2015, 08:03:38 PM
Do you have or can you borrow a GPSr? Secure (tape) it somewhere near your dash and go for a ride and compare readings at various speeds, say, common speed limits.

I have. Its 5 mph fast exactly at all speeds. That's why I was wondering if it was adjustable . It makes sense that it's not tho. It would be cool of they made an aftermarket digital one that would fit like I oem
Title: Re: Speedometer/ odometer
Post by: FJmonkey on May 31, 2015, 08:44:08 PM
The speedo and ODO are separate, the error in the speedo does not affect the ODO. The speedo works on magnets, the ODO is mechanical. There is a place in San Diego that repairs our Japanese speedos and might also have a way to tune them. My speedo can swing from peg to peg at freeway speeds on my '89, but I use my GPS and let the speedo party on...
Title: Re: Speedometer/ odometer
Post by: aviationfred on May 31, 2015, 09:45:27 PM
Quote from: twangin4u on May 31, 2015, 08:17:11 PM

It would be cool of they made an aftermarket digital one that would fit like I oem



There are a couple of options. A few members have installed Speed Hut GPS speedometers with great success. Check out this link. go to the last page and there is a complete write up for the install. http://www.fjowners.com/index.php?topic=3148.msg119989#msg119989 (http://www.fjowners.com/index.php?topic=3148.msg119989#msg119989)

I installed a digital speedometer but the modification was much more extensive. Here is the link. http://www.fjowners.com/index.php?topic=12391.msg123220#msg123220 (http://www.fjowners.com/index.php?topic=12391.msg123220#msg123220)

I also did a digital Tachometer mod. The first tach attempt failed. The second page shows the successful Digital speedometer and digital Tachometer. http://www.fjowners.com/index.php?topic=12405.msg123521#msg123521 (http://www.fjowners.com/index.php?topic=12405.msg123521#msg123521)

Fred
Title: Re: Speedometer/ odometer
Post by: Firehawk068 on June 01, 2015, 07:19:48 AM
Quote from: FJmonkey on May 31, 2015, 08:44:08 PM
The speedo and ODO are separate, the error in the speedo does not affect the ODO. The speedo works on magnets, the ODO is mechanical. There is a place in San Diego that repairs our Japanese speedos and might also have a way to tune them. My speedo can swing from peg to peg at freeway speeds on my '89, but I use my GPS and let the speedo party on...

Mark is right.
I've tested mine with my GPS. My speedometer is about 12% off (reads too fast). The faster you go, the more it is off.
However, my odometer is only about 5% off. (tested over numerous tanks of gas)
Title: Re: Speedometer/ odometer
Post by: twangin4u on June 02, 2015, 07:14:54 PM
Quote from: FJmonkey on May 31, 2015, 08:44:08 PM
The speedo and ODO are separate, the error in the speedo does not affect the ODO. The speedo works on magnets, the ODO is mechanical. There is a place in San Diego that repairs our Japanese speedos and might also have a way to tune them. My speedo can swing from peg to peg at freeway speeds on my '89, but I use my GPS and let the speedo party on...

Cool. I assumed that they dud work in conjunction because along with being 5 mph off it also measures a mile about 1/4 to 1/3 of a 1/10th shorter than it should. I'm gonna check my tire size when I get home.
Title: Re: Speedometer/ odometer
Post by: FJmonkey on June 02, 2015, 09:17:39 PM
I checked my ODO during the WCR with my GPS over a tank of fuel. Based on this one measurement it is 5% over. But I am also not on OEM size wheels and tires.
Title: Re: Speedometer/ odometer
Post by: krusty on June 03, 2015, 12:32:20 AM
With the previous posts in mind I today decided to check my FJ1100 speedo against my Garmin Etrex 20 GPSr. Needed to take it for a run anyway to bed in the new Vmax discs and brake pads before a VJMC ride this Sunday. Ran it up to 110kph indicated and held it steady there  for a while then pulled over and checked it against the GPSr (which was in my pocket). GPS showed 103kph. 7% error. About the same as our 2010 Subaru Forester.
Title: Re: Speedometer/ odometer
Post by: Harvy on June 03, 2015, 01:37:16 AM
When all the GPS satellites go fritz my speedo will still be accurate. The Acewell is based on wheel circumfrence - only time its wrong is when the front wheel is in the air.    :rofl2:
Title: Re: Speedometer/ odometer
Post by: oz.fj on June 03, 2015, 01:51:40 AM
Quote from: Harvy on June 03, 2015, 01:37:16 AM
When all the GPS satellites go fritz my speedo will still be accurate. The Acewell is based on wheel circumfrence - only time its wrong is when the front wheel is in the air.    :rofl2:

A ha !
So you weren't doing 220kmh in 3rd   :rofl2: