I recently purchased a 1993 FJ1200. It's really a nice bike. However, it did have a couple of problems. It wasn't charging correctly and the tach was reading double what it should. I took it to the dealer as I'm not the greatest when it comes to motorcycle repairs. The dealer put in a new voltage regulator that took care of the charging problem. They indicated on the invoice that the tach was ok. but, as I was riding home I notice that the tach was still doubling. I took the bike for a 100 mile ride just to see what would happen, it ran great and at one point the tach actually settle down and read the correct RPM's for a short time. When I call the dealer back that couldn't tell me if the tach runs off the alternator or the coil. I actually called three different dealers and all were the same "clueless". Can anyone out there give an old veteran some insight on this problem?
Tach is fed from the coils. It has been suggested that a bad coil ground will cause you tach woes. Mine started after I added the electronic cruise control. It is also aggravated by low battery voltage, such as at idle after start-up. Never really goes away for long, and is only noticeable below ~3k rpm.
My 2ยข
Ed, Thanks for the feedback. :good2:
Think I'll try to pull everything apart this weekend and check all of the connections.
Again, thanks for your help.
MSG G
My tach intermittently goes from correct to wildly high, usually for long periods of each. I completely rebuilt my entire ignition system from the battery on up, so I'm quite certain I don't have a ground. I tore apart my dash and couldn't find anything that looked out of place. It happens in cold weather and hot weather. It happens in torrential downpours and when it's bone dry. I have given up on the whole affair.
Quote from: MyFirstNameIsPaul on September 10, 2009, 10:30:38 PM
My tach intermittently goes from correct to wildly high, usually for long periods of each. I completely rebuilt my entire ignition system from the battery on up, so I'm quite certain I don't have a ground. I tore apart my dash and couldn't find anything that looked out of place. It happens in cold weather and hot weather. It happens in torrential downpours and when it's bone dry. I have given up on the whole affair.
Paul-
You have stock coils then?
I wonder if anyone (Rich I'm +/- refering to you) has been able to correct/ reproduce this behavoir after coil replacement.
Seems like there been a rash of this happening, sure would be nice to get to the bottom of what may be causing it.
Anyone?
Dan
I have all Dynatek components.
I took the bike out today, and the tach was right on the money. The temp has dropped to around 70. I was talking to a friend of mine that's really in to cars and bikes. He said that since the tach is running off the coil and that it arrears that the temp is directly related to the problem it is a ground problem. This guy is Mr motorhead. He said that as the temp rises the resistence in the coil will increase and if the ground is not perfect is will case the reading to go nuts. I going to tear it apart next week to see what I can find.
Quote from: MSG Groves on September 13, 2009, 11:47:22 AM
I took the bike out today, and the tach was right on the money. The temp has dropped to around 70. I was talking to a friend of mine that's really in to cars and bikes. He said that since the tach is running off the coil and that it arrears that the temp is directly related to the problem it is a ground problem. This guy is Mr motorhead. He said that as the temp rises the resistence in the coil will increase and if the ground is not perfect is will case the reading to go nuts. I going to tear it apart next week to see what I can find.
there is a coil ground right at the coils mounting location..... doing a thorough cleaning in this area may just fix your problem.
KOokaloo! :yahoo:
I have the same problem and posted on General Discussion, but this is where I belong!
I removed the tank, tightened the ground connection at the mounting point of the coils. NO LUCK.
Then I re-removed the tank, removed the nut/bolt that hold the coils in place, took sandpaper and
steel wool to clean them up, even turned the nut/bolt around and tightened it real tight. NO LUCK.
Then I thought there might be an unnecessary drain on the battery, so I removed an auxilary plug
I had connected to the battery posts. NO LUCK
It reads 2,000 rpms at idle and 7,000 rpms at 35 mph in 2nd.
Here are photos of of the area I was working around...any more suggestions of what I should try?
(http://torno.smugmug.com/photos/650629898_KymvH-L.jpg)
(http://torno.smugmug.com/photos/650629991_qEgDp-L.jpg)
and if that's not where I need to be checking, here's the ugly side of the bike...
(http://torno.smugmug.com/photos/650630021_eLrhn-L.jpg)
:dash1:
Quote from: thkfast on September 15, 2009, 02:27:33 PM
I removed the tank, tightened the ground connection at the mounting point of the coils. NO LUCK.
Then I re-removed the tank, removed the nut/bolt that hold the coils in place, took sandpaper and
steel wool to clean them up, even turned the nut/bolt around and tightened it real tight. NO LUCK.
That's not the correct ground. That's just an external ground to prevent a shock in case the coil shorts out internally.
See those connectors up near the steering head? Two of them are coil connectors, the other one is the ignition connector. Make sure their contacts are clean! This is also where you would measure the voltage getting to the coils. According to my wiring diagram, one coil connector has an orange wire and the other has a grey wire (both connectors have the red/white power wire). The orange and grey wires are the ground side of the circuit which is switchd by the ignitor in order to fire the coils. The tach reads the signal on the grey wire. Chase that wire as far as possible. I would suspect it has a loose connection somewhere that is falsely indicating extra coil firing events. I have no idea where you should look, but the back side of the tach or one of the large fairing connectors are prime candidates.
DavidR.
Gotcha!
I'll chase that grey wire as far as possible. Now, when it comes to "cleaning" the connectors, do you mean
unplug them and swirl a Q-tip dipped in alcohol around up in there? I appreciate your suggestions!
Quote from: thkfast on September 15, 2009, 06:28:50 PM
Gotcha!
I'll chase that grey wire as far as possible. Now, when it comes to "cleaning" the connectors, do you mean
unplug them and swirl a Q-tip dipped in alcohol around up in there? I appreciate your suggestions!
Or scrape any green corrosion off of them. They tend to get a fair amount of water on them if you ride in the rain or wash the bike frequently, which can lead to corrosion. It's a good idea to periodically inspect/clean/lube any/all connectors you can get your hands on. Even removing the fairing to get to the other hard to reach connectors is a adviseable.
Years ago, Norbert showed up at a rally on Calvin's bike because his '89 lost fire on 2 cylinders as he was headed through Va. Once the recalcitrant bike was delivered to the rally on a trailer, Andy York, himself, tried to find and fix the problem. Then I took a turn, followed by several other poeple. We swaped relays and every other black box we could get to. Nothing was working. Finally, Andy just started pulling connectors. Everything he could get his hands on. Nothing really looked out of order, but when we put everything back together, suddenly the problem was gone!
Moral: A little connector cleaning can sometimes work magic.
DavidR.
UPDATE: Talking to my Yamaha Service Advisor, he believes either the tach is going bad (I don't think so) or there's a problem with the CDI. I think it's buried under the right side fairing...I can't see it. I'll re-post after I take the bike in.
Hey! And it's only $629...oh shit.
Don't even think about replacing the stock CDI black box. If it's bad (whcih I seriously doubt) then install a Dyna instead. Significantly cheaper than the $600!
If the CDI was bad, then the engine would have some kind of trouble running. The tach wire is spliced into a coil ground wire and the tach just counts the on/off voltage transitions. Maybe a problem with the tach, but the CDI should be fine.
DavidR.
Okay. Yeah bike runs perfectly. I'm slowly pulling stuff apart to get behind the fairing to physically get at all the wires going to the tach. Unplugging and plugging back in anything and everything I can get my hands on! The thought of pulling the entire fairing off sucks. Thanks again.
Pulling the fairing on a '93 is a piece of cake compared to getting it off of an '84/'85. Just be careful not to drop the headlight. You can pull the gauge cluster, and check that connector without removing the entire fairing. But, it's not that much work to remove the whole thing. That will give you easier access for checking/cleaning connectors and maybe tidy things up so they don't rattle around.
DavidR.
DavidR.
With mine, I'm pretty sure its the tach..... there's never been a change in the way the engine runs every time the tach has acted up. I've got to replace the water pump in my van, then I plan to pull the tank and fairing and do some much needed maintenance. I'll double-check the wiring, install my DYNA coils and swap gauge clusters then..... I won't know which fixed it, but it SHOULD be fixed.
Quote from: MSG Groves on September 08, 2009, 04:10:31 PM
I recently purchased a 1993 FJ1200. It's really a nice bike. However, it did have a couple of problems. It wasn't charging correctly and the tach was reading double what it should. I took it to the dealer as I'm not the greatest when it comes to motorcycle repairs. The dealer put in a new voltage regulator that took care of the charging problem. They indicated on the invoice that the tach was ok. but, as I was riding home I notice that the tach was still doubling. I took the bike for a 100 mile ride just to see what would happen, it ran great and at one point the tach actually settle down and read the correct RPM's for a short time. When I call the dealer back that couldn't tell me if the tach runs off the alternator or the coil. I actually called three different dealers and all were the same "clueless". Can anyone out there give an old veteran some insight on this problem?
The alternator system does not have any affect on the tachometer.
For some reason your tach is receiving the coil signal from both coils, when it should only be reading from one. I would hunt out the specific wire which looks like it is grey(gr) for the tach for your year model. That wire should run from the tach to the grey primary wire on one of the two coils. The other coil should have an orange wire. The other primary wire on each of the coils will be red with a white stripe. That is the power source to each coil.
There appears to be one connector in the loom, make sure corrosion has not allowed the circuit to be reading from the other coil. From there I would run a separate wire from the coil to the tach, eliminating the factory wiring.
There is a black (B) wire from the back of tach that appears to be the ground circuit for all of the gauges/lights.
The last wire is a brown (Br) that runs from the tach to the "resistor" the back to the "fuel pump control" relay. It is also part of the following circuits; Fuel Gauge, ABS warning and Neutral indicator lights. If those systems are functioning properly, you can probably move past that wire.
I would run the separate wire to the tach & coils first to eliminate try and eliminate the problem first.
I think if it was the CDI the engine would not know which coil was supposed to be firing at what time, and it would not run.
That is the diagnosis I would start with for the problem.
Randy - RPM
Alright, everything is pretty much torn apart now. I can see the grey wire come out of one of the coils, it goes into a white square plug, where it joins several other wires, then into a massive wrapped wiring harness where it T's off in all directions. From the other end, at the gauges, I can clearly see 1 grey wire screwed into the bottom of the cluster all by itself and it's tight. I started the bike and tapped, wiggled & played around with all the wires at the back of the cluster - no change in RPM. Are you suggesting I cut the grey wire at the gauge cluster & coming out of the coil and temporarily splice in a section of wire to see what happens?
Yep,
If the wire is screwed into the back of the gauge, remove that wire and insulate. Install a new wire that you can screw on the gauge and then run it down to the coil. cut it somewhere that you can install a connector and try that. My thoughts are if there is still the issues from there the tach is bad.
Randy - RPM
CONCLUSION:
Okay. I totally disassembled the fairing, gauge cluster, unscrewed the CDI - FULL ACCESS IN OTHER WORDS. Checked all possible connections - all look like new - unplugged, wiggled, re-pluged in. The bike is naked. Unscrewed the grey wire entering the bottom of the tach - started bike, no tach. Fashioned a new jumper wire and crimped the appropriate end on it, screwed it into tach and connected the other end to the grey wire coming out of the right side coil just after the snap connector junction - started the bike, tach still reads double rpm's. I'm assuming the CDI is fine because bike runs like a champ, there's apparently no shorts in the wiring loom going to the tach. The needle isn't jumping around like crazy...just double the rpm. Unless I missed something, I'll take some photos of it disassembled, then put her back together tomorrow. :flag_of_truce:
If the black ground wire also screws on the rear of the tach, make another ground to a new clean grounded connection and give that a try before you put it all back together. Just to cover the fact the ground wire to the tach could be bad.
Randy
Randy,
Did as you suggested, unplugged the black wire on back of tach next to the grey wire - ran bike, of course no tach. Then connected a jumper wire in same spot and grounded it to the frame and tach reads same high rpms. The nice thing is I have total access to EVERYTHING right now. Let me know if there's anything else you'd check. Will hold off on reassembly a while. Thanks!
Here's where I tapped into the grey wire after the connector off one of the coils
(http://torno.smugmug.com/photos/655118354_LWX8o-M.jpg)
Here's where the brown - black - grey wires power the tach
(http://torno.smugmug.com/photos/655118386_jcSjd-M.jpg)
And finally the bare naked front end of the bike
(http://torno.smugmug.com/photos/655118418_k7TMg-M.jpg)
The bike is now back together and tach still reads double rpms - I'll ride it awhile and see if it fixes itself... :wacko3:
Hate to say I told you so, but, I told you so.
From what you've done so far, I would have to conclude that a circuit in the tach has gone bad. If it is reading exactly double, then it sounds like it must be counting the "wasted spark" event. At this point, you probably need to replace the tach, unless you can find an electronics person that can locate and replace the bad component.
DavidR.
Agreed.
Yeah yesterday I started the bike cold (it was about 78 degrees outside) required a little choke. At first,
the rpms were READING CORRECTLY! I thought OMG, it's fixed. But by the time I rolled it off the center
stand and started down the street, I could see the rpms slowly rising to X2. I tried it again just now cold
and it's doing the X2 thing. eBay gauge clusters look pretty nasty - cracked and scratched $95-200 gamble.
I'll keep my eyes open for a decent gauge cluster...
Thanks guys!
CONCLUSION: I FIGURED OUT WHAT WAS WRONG WITH MY TACH!
It appears I wasn't riding it enough. We had some crappy days, I had been driving the car more and neglecting the FJ12. Once I resumed riding again, the tach started working intermitantly, then for the first 2 miles or so, then today it just started working right - period. Now that was an easy lesson!
(http://torno.smugmug.com/photos/662785177_LCszz-L.jpg)
Quote from: thkfast on September 27, 2009, 04:44:46 PM
CONCLUSION: I FIGURED OUT WHAT WAS WRONG WITH MY TACH!
It appears I wasn't riding it enough.
The cure for oh, so many problems!
Hope it stays that way!
Dan
Quote from: SlowOldGuy on September 22, 2009, 09:51:18 AM
From what you've done so far, I would have to conclude that a circuit in the tach has gone bad. If it is reading exactly double, then it sounds like it must be counting the "wasted spark" event. At this point, you probably need to replace the tach, unless you can find an electronics person that can locate and replace the bad component.
DavidR.
It should be calibrated to count the wasted spark event...... these actually read the pulse train as a proportional voltage. All the tach is is a voltmeter, nothing fancy....
We're almost back to bearable temps here in Tucson, and I'll be doing some work on my '90. I'll swap out the guage cluster then and I plan to open up the tach and see what they're doing with it.
Quote from: thkfast on September 17, 2009, 09:17:04 PM
UPDATE: Talking to my Yamaha Service Advisor, he believes either the tach is going bad (I don't think so) or there's a problem with the CDI. I think it's buried under the right side fairing...I can't see it. I'll re-post after I take the bike in.
Hey! And it's only $629...oh shit.
Thats why most folks here call dealers, STEALERS.... trust me the collective here know worlds more about FJ's than any dealership you can find....
Eric M
Quote from: SlowOldGuy on September 18, 2009, 01:50:34 PM
Pulling the fairing on a '93 is a piece of cake compared to getting it off of an '84/'85.
I don't know what '84 or '85 FJ's you were pulling a fairing off, but it's 6 bolts and the pop-pins for the intake scoops. The only thing that I've had an easier time pulling the fairing off didn't have a fairing to begin with. Takes a minute, tops.
Dennis
Quote from: E Double on November 06, 2009, 09:11:07 PM
Quote from: SlowOldGuy on September 18, 2009, 01:50:34 PM
Pulling the fairing on a '93 is a piece of cake compared to getting it off of an '84/'85.
I don't know what '84 or '85 FJ's you were pulling a fairing off, but it's 6 bolts and the pop-pins for the intake scoops. The only thing that I've had an easier time pulling the fairing off didn't have a fairing to begin with. Takes a minute, tops.
Dennis
It's an awkward PITA compared to getting the fairing off of a 1200. Getting it off of and onto those stupid pins down near front of the head always seems like it's going to snap the corner off. I always cringe at that part.
DavidR.
I used this old thread to chase down a tach problem, so I'm adding this to it for posterity.
Intermittently, my tach would read 2000-3000 no matter what the engine was doing. Neutral light working intermittently as was the fuel gauge. Bike was running fine.
I lucked out and found that it was just a loose connector that wasn't quite snapped together. Pushed it back together and everything is back to normal. I must have pulled it apart accidentally when I was working on the bike recently.
Picture of which connector below. ---center, circled in red.
(http://fjowners.com/gallery/150_11_04_10_11_22_39.jpeg)
Thanks Mark for checking in and letting us know what you did, and how you fixed it.....