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just wondering if a jumpy tach might be caused by the diode in the feed wire breaking down, not clipping the voltage signal cleanly due to age ect. anyone know what Radio Shack number/type to use as a replacment?
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where are we going, and why are we in this hand basket?
Iowa the Beautiful Land 1980 XS1100SG -
Its usually caused by the terminal block from the generator being corroded or melted, usually both.
Its the terminal block with the white wires thats behind the fuse box.
The tach takes a feed from one of the white wiresTom
1982 5K7 Sport, restored to original from a wreck
1978 2H9 (E), my original XS11, mostly original
1980 2H9 monoshocked (avatar pic)http://i145.photobucket.com/albums/r...psf30aa1c8.jpg
1982 XJ1100, waiting resto to original -
Or the integrated circuit inside the tach. Does it jump at just a certain RPM range or all ranges?Originally posted by TomB View PostGreg
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein
80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.
The list changes.
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4000 to 4200 pretty stable thru the rest of the range, all connection pulled apart, cleaned, di-electric greased, checked grounds, so diode or internal tach problem ... 4000 is my 60mph cruise with the 850FD conversion also liked going from 32 mpg to 37.5 mpgOriginally posted by BA80 View PostLast edited by jayel; 06-10-2012, 07:46 AM.where are we going, and why are we in this hand basket?
Iowa the Beautiful Land 1980 XS1100SGComment
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OK, that's going to be in the IC. Not much you can do about it other than try another tach.
If it makes you feel any better mine does it too
right at the cruising range (also w/850 FD) between 4 & 5K.
I think the IC goes bad right in that range simply because that is where it spends most of it's time.
I'm nowhere near an electronics expert but that's the only thing that makes sense to me.Greg
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein
80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.
The list changes.Comment
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What about one that jumps around at all ranges. I've pulled the connectors and used contact cleaner and inserted repeatedly then re-sprayed and assembled.. While better it still jumps randomly at all RPMS. have another coming just to test with. Don't know if it matters but my charging circuit works.1970? Honda Z50... gone
1974? Yamaha 100 Enduro... gone
1974 Honda CB200... gone
1981 Yamaha Virago 750... gone
1993 Honda Shadow 1100... gone
2008 Honda VTX 1800F
1982 Yamaha XJ1100J w/850 final, Raptor ACCT
1979 Yamaha XS1100SF "Chewey" Raptor ACCT
http://www.johnsoldiron.comComment
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That in my opinion is a bad connection. Either in the harness or in the tach itself.
The vibration is causing intermittent contact. Try reaching up and holding the tach still while your riding and see if that makes a difference. Don't crash though.
Greg
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein
80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.
The list changes.Comment
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Likely what Greg says. You might try going in and carefully resoldering all the joints in the tach which might help as often cold solder joints can be the source of poor connections inside of devices when the wire connections are fine. Mine works find so I've not gotten into the troubleshooting that type of stuff yet.Cy
1980 XS1100G (Brutus) w/81H Engine
Duplicolor Mirage Paint Job (Purple/Green)
Vetter Windjammer IV
Vetter hard bags & Trunk
OEM Luggage Rack
Jardine Spaghetti 4-2 exhaust system
Spade Fuse Box
Turn Signal Auto Cancel Mod
750 FD Mod
TC Spin on Oil Filter Adapter (temp removed)
XJ1100 Front Footpegs
XJ1100 Shocks
I was always taught to respect my elders, but it keeps getting harder to find one.Comment
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I got a box full of screwed up ones. You want 'em?Greg
Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.”
― Albert Einstein
80 SG Ol' Okie;79 engine & carbs w/pods, 45 pilots, 140 mains, Custom Mac 4 into 2 exhaust, ACCT,XS850 final drive,110/90/19 front tire,TKat fork brace, XS750 140 MPH speedometer, Vetter IV fairing, aftermarket hard bags and trunk, LG high back seat, XJ rear shocks.
The list changes.Comment
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Built with jumpy tach
Within the first 2 or 3 weeks of getting my XS11 in '79, I took it in for service, one of the items being an erratic needle on the tach. The dealer said there was a service bulletin to change out the tachs on the '79s. They put in a new tach (after waiting about a month) and it was markedly better. But even now, 33 years later it is not a smooth movement when I go through the gears. I have just learned to live with it. I seem to remember it being written up in some of the bike magazines back then in the technical forums.
Just my $0.02 (from an aging memory).79 XS11Comment
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