Tachometer moving slugishly

[MattK]

I have a 81 GS 750L, which runs well, but I have this problem. Last year when I put it up it was just fine, but now the Tach moves very slowly. It does move but it acts like the needle is in cased in gel. It moves but very slowly. What can I do to correct this?

 

[Guest]

check for the cable connections first (at the tacho and at the engine) - undo, re-do, check if it made any difference
check the cable itself operates freely (take it off and rotate by hand)
(lubricate it even if it does, and if it doesnt, replace it)
see that the tacho gear rotates freely too

hopefully some of the above solves your problem

the next step is to replace the tacho, or open it up to see what the %#!?=% is going on inside

 

[flatblack850L]

My GS850L had the same problem, I had to pry the outer ring off the tach and take it apart. The cup inside where the needle pivots on had a glob of grease on it and slowed the needle right down. I cleaned it out and it works just like new, I think it's a non serviceable part though, It's not as pretty as it once was after I managed to pry the ring off and crimp it back on again. Or, replace the tach for lots of money, mine's not a show bike, just functional.

 

[tkent02]

Turn the tach upside down, put oil in between the spinning part the cable turns and the stationary tube around it.

 

[Calvin Blackmore]

i have had 3 tach cable go
call me lucky
anyhow the wound spring wire of the cable tends to break and for want of a better word twist when it is um wisted

bottom end moves and there is a llag tme for the top to catch up cause of twisting
pull out the stell inner cable and inspect it for um
torsional integrity
again for want of a better word.

 

[duaneage]

Funny, I grafted a 80 750L dash onto my 650 and the tachometer did the same thing. I wonder if it was a common problem to a run of tachs?

 

[BassCliff]

Hey howdy hey!

Hey howdy hey!

Hi Mr. MattK,

Let it be known that on this day you are cordially and formally welcomed to the GSR Forum as a Junior Member in good standing with all the rights and privileges thereof. Further let it be known that your good standing can be improved with pictures (not you, your bike)!

Perhaps you've already seen these, but I like to remind all the new members. In addition to the carb rebuild series, I recommend visiting the In The Garage section via the GSR Homepage and check out the Stator Papers. There's also a lot of great information in the Old Q&A section. I have some documentation on my little BikeCliff website to help get you familiar with doing routine maintenance tasks (note that it is 850G-specific but many tasks are common to all GS bikes). Other "user contributed" informational sites include those of Mr. bwringer, Mr. tfb and Mr. robertbarr.

And here are some edited quotes from one of our dear beloved gurus, Mr. bwringer, with ideas on basic needs (depending on initial condition), parts, and accessories.

***********Quoted from Mr. bwringer************
Carburetor maintenance:

Replace the intake boot o-rings, and possibly the intake boots. Here's the procedure:
http://bwringer.com/gs/intakeorings.html
Here's an overview of what happens with this particular problem:
http://cycleorings.com/intake.html
You'll also want to examine the boots between the carbs and the airbox. There's a good chance these are OK, but check them over.
And finally, if things still aren't exactly right, you'll want to order a set of o-rings for BS carbs from the GS owner's best friend, Robert Barr:
http://cycleorings.com
Once you receive these rare rings of delight, then you'll want to thoroughly clean and rebuild your carburetors. Here are step-by-step instructions that make this simple:
http://thegsresources.com/gs_carbrebuild.htm
***********************************
Every GS850 has (or had) a set of well-known issues that MUST be addressed before you have a solid baseline for further troubleshooting. It's a vintage bike, and it's quite common (as in, every single GS850 I have had contact with) that there are multiple problems that have crept up and slowly gotten worse over the years. It's not like a newer vehicle, where there's generally one problem at a time.

These common issues are:

1. Intake O-rings (install NEW OEM or Viton only - common nitrile O-rings will quickly deteriorate from heat)
2. Intake Boots (install NEW -- these cannot be repaired)
3. Valve clearances (more important than most people think)
4. Carb/airbox boots
5. Airbox sealing
6. Air filter sealing
7. Petcock (install a NEW one)
8. On '79 models, install new points or Dyna electronic ignition (or at least verify that the old points are working correctly)
9. On all models, it's fairly common to have problems with the spark plug caps. These are $3 or $4 each, and often worth replacing if you're keeping the stock coils/wires.
10. Stock exhaust with NO leaks or holes -- good seals at the head and at the junctions underneath.
***************************************
OEM Parts/Online Fiches:

I would definitely double and triple the recommendations to use Cycle Recycle II and Z1 Enterprises as much as possible. These guys are priceless resources. Z1 tends to have slightly better prices, CRC2 has a wider range of goodies available. If you're near Indy and can bring in an old part to match, CRC2 has a vast inventory of used parts.
http://denniskirk.com - Put in your bike model and see what they have.
http://oldbikebarn.com - seems to be slowly regaining a decent reputation, but it's still caveat emptor. They don't have anything you can't get elsewhere at a better price anyway.
http://www.babbittsonline.com/ - Decent parts prices. Spendy shipping. Don't give you part numbers at all. Useful cross-reference if you obtain a part number elsewhere. Efficient service.
http://bikebandit.com - Fastest. Middlin' prices. Uses their own parts numbering system to obfuscate price comparisons -- can be very confusing for large orders. Cheapest shipping, so total cost usually isn't too bad.
http://flatoutmotorcycles.com - Slow. Cheapest parts prices, crazy shipping costs. Don't expect progress updates or much communication. Real Suzuki part numbers.
http://alpha-sports.com - Exorbitant parts prices. Different type of fiche interface that's quite useful at times, especially with superceded part numbers. Real parts numbers. Shipping cost and speed unknown due to insane, unholy pricing.

Stainless Bolts, Viton o-rings, metric taps, dies, assorted hard-to-find supplies and materials, etc:

http://mcmaster.com - Fast, cheap shipping, good prices. No order minimum, but many items like bolts come in packs of 25 or 50. Excellent resource.
http://motorcycleseatcovers.com - Great quality, perfect fit (on original seat foam), and available for pretty much every bike ever made. Avoid the textured vinyl -- it's perforated.
http://newenough.com - You DO have riding gear, don't you? Great clearances, always outstanding prices and impeccable service.
***************End Quote**********************
Here are some extra links:

GSR Forum member Mr. duaneage has great used upgraded Honda regulator/rectifiers for our bikes. Send him a PM.
New electrical parts:
http://stores.ebay.com/RMSTATOR or http://www.rmstator.com/
http://www.ricksmotorsportelectrics.com/index.php
http://www.electrosport.com/
The Rice Paddy (salvage/used)
http://www.ricepaddymotorcycles.com
Ron Ayers Motorsports
http://www.ronayers.com
MR Cycles
http://www.mrcycles.com
If all else fails, try this:
http://www.used-motorcycle-parts.org/
Lots of good info/pictures here:
http://www.suzukicycles.org
http://www.cyclechaos.com/wiki/Motorcycle_Wiki

Thanks for joining us. Keep us informed of your progress. There's lots of good folk with good experience here.

Thank you for your indulgence,

BassCliff
(The unofficial GSR greeter)

 

[KTA]

Turn the tach upside down, put oil in between the spinning part the cable turns and the stationary tube around it.

A sluggish tach is a common problem. I have fixed them with this method before. Lube it up!