Strange Tach...

Flynt · October 18, 2011, 06:53:44 PM

I started the FJ after a week off and the tach was strange... kind of wavering around and indicating about 2X the actual RPM. This had happened once in the past, but a stop and restart fixed it. I tried several stop/start cycles with no effect, then rode on for my destination. 10 min into the ride, I noticed the tach slowly dropping and it came back to "true" RPM within about 15 min.

Anyone seen this before? Is it an early indication of a failure I am about to experience?

Frank

BTW - the ride itself was exceptionally nice... great weather today and the Reg Pridmore riding school I took last week just makes a huge difference in my confidence on the bike.

Flynt · October 20, 2011, 09:56:06 AM

Quote from: Flynt on October 18, 2011, 06:53:44 PM
I started the FJ after a week off and the tach was strange... kind of wavering around and indicating about 2X the actual RPM. This had happened once in the past, but a stop and restart fixed it. I tried several stop/start cycles with no effect, then rode on for my destination. 10 min into the ride, I noticed the tach slowly dropping and it came back to "true" RPM within about 15 min.

Anyone seen this before? Is it an early indication of a failure I am about to experience?

Nobody has experienced this "floating tach" thing? It has not happened again in the last couple of rides, so I'm not going to fret about it... but would like to know if it is telling me a problem is developing... I'll do some additional searching.

Frank

rktmanfj · October 20, 2011, 11:34:33 AM

Quote from: Flynt on October 20, 2011, 09:56:06 AM
Quote from: Flynt on October 18, 2011, 06:53:44 PM
I started the FJ after a week off and the tach was strange... kind of wavering around and indicating about 2X the actual RPM. This had happened once in the past, but a stop and restart fixed it. I tried several stop/start cycles with no effect, then rode on for my destination. 10 min into the ride, I noticed the tach slowly dropping and it came back to "true" RPM within about 15 min.

Anyone seen this before? Is it an early indication of a failure I am about to experience?

Nobody has experienced this "floating tach" thing? It has not happened again in the last couple of rides, so I'm not going to fret about it... but would like to know if it is telling me a problem is developing... I'll do some additional searching.

Frank

Not exactly... mine sometimes reads nothing until it gets bumped by a light tap on the lens, small bump in the road, whatever... then it reads normally until the next ride. Lately it has been a bit more stubborn about coming up though, so I suppose I will take time to fix it when I have the fairing off this winter. I do have a couple of spares on the shelf, so if it gets to be too much of an effort, I'll just swap it out.

If you want a spare tach to aid in your troubleshooting, send a PM, and I'll get one out to you.

Mark Olson · October 20, 2011, 12:05:55 PM

mine just quit one time with no warning , the replacement worked fine and will sometimes bounce up or read slow.

all connections are good so you got a weird one there.

flips · October 20, 2011, 01:36:51 PM

Hi there.
Could be that your tacho is failing but mine was doing the same thing until I ran a new ground cable up to the fairing stay when I installed some spot lights and a set of air horns and it "magically" started working properly again.Could be a bad ground connection.Hope this helps.

Cheers

Jeff P

FJ111200 · October 20, 2011, 01:47:19 PM

On the old XS1100, the first sign that there is a dodgy connection between, or ultimately that the rectifier has packed up, is that the tacho dies. Just a thought.
Saying that, i've owned 3 FJ's now and the rectifiers have all been good, and 3 XS's and one rectifier has died.
As i say, JAT, check the connectors.

markmartin · October 20, 2011, 02:35:18 PM

Probablyly not this, but worth a mention. http://www.fjowners.com/index.php?topic=844.msg14357#msg14357

My neutral light and fuel guage were acting up along with the tach.

Mark

Flynt · October 21, 2011, 09:24:21 AM

Quote from: markmartin on October 20, 2011, 02:35:18 PM
Probablyly not this, but worth a mention...

Thanks all for the tips... I went through the wiring thoroughly, checked connections and grounding, fiddled with everything I could while watching the tach, no effect. I will take the offer of another tach for troubleshooting and take it to the next level (fairing removal). As part of this effort, I'd like to replace my inner fairing pieces out... mine are rough and are the low point for the bike now. Anyone have a line on great condition inner fairing for a '92?

Frank

Pat Conlon · October 21, 2011, 11:31:12 AM

Hello Frank, sorry for the late reply. Regarding the tach, check the grounding at the coils. Emery cloth all the connections.
The right side inner panel is still available new from Yamaha ($276 ouch). http://www.powersportsplus.com/parts/search/Yamaha/Motorcycle/1992/FJ1200D/COWLING+2/parts.html

When ordering from this Power Sports Plus web site, at checkout, use coupon code "meetsister" and get another 15% off. Hope this helps Pat

Flynt · October 21, 2011, 04:51:11 PM

Quote from: Pat Conlon on October 21, 2011, 11:31:12 AM
Hello Frank, sorry for the late reply. Regarding the tach, check the grounding at the coils. Emery cloth all the connections.

I will try that over the weekend... It "looks" like noise in the tach trigger line and I have seen similar things in old Datsuns. I need to dive in a bit deeper and drive that potential source to ground (ha). I'm also trying to line up a working tach to eliminate the potential I've got a bad one.

Frank

Dan Filetti · October 22, 2011, 05:54:54 AM

Quote from: Pat Conlon on October 21, 2011, 11:31:12 AM
...check the grounding at the coils. Emery cloth all the connections...

I'm with Pat, the connection at the coils is the first place I'd look, the ground connection next. Then as above, I'd swap out a different tach...

Dan

RichBaker · October 23, 2011, 12:14:19 AM

Quote from: Pat Conlon on October 21, 2011, 11:31:12 AM
When ordering from this Power Sports Plus web site, at checkout, use coupon code "meet sister" and get another 15% off. Hope this helps Pat

Pat, is that code good fqr a while, or just short term?

Pat Conlon · October 23, 2011, 12:52:26 AM

I don't know the expiration date. It's been working since June 25th when I ordered from Boats.net. The invoice said:
Want to meet our sister? She's got what you want!
PowersportsPlus.com sells Honda, Kawasaki, Suzuki and Yamaha Powersports Parts at discounts up to 80% off MSRP.
Take an additional 15% off by using promo code: meetsister

I just ordered more goodies last week from the PowersportsPlus website and the promo code still worked.

heck 15% is 15%

Flynt · October 23, 2011, 10:16:21 AM

Quote from: Dan Filetti on October 22, 2011, 05:54:54 AM
Quote from: Pat Conlon on October 21, 2011, 11:31:12 AM
...check the grounding at the coils. Emery cloth all the connections...

I'm with Pat, the connection at the coils is the first place I'd look, the ground connection next. Then as above, I'd swap out a different tach...

Dan

Nice clean coil connections and grounds... still no joy. I'll be trying another tach hopefully next weekend.

This 2X RPM reading is actually not that bad once you're used to it... makes you feel like you're twisting the throttle on a 600cc rocket. I have not found any apparent downside, so I'm still riding for now.

Thanks for the help so far.

Frank

Flynt · November 03, 2011, 08:13:19 PM

So yesterday and today the tach is perfectly fine

What did I eventually find... divine intervention. I last worked on her the day I wrote the previous post and have just ridden by ear. Really not so hard.

Then yesterday I fire her in the morning and tach reading is correct. WTFO?

I have another tach from Randy T and have spent 3 hours on this phantom already

I want to fix it!

Guess I'm ready in case (when) it happens again and know a few things that are not the problem.

Frank

News:

Strange Tach...

rktmanfj