GS850 [and most other
models] has (or had) a set of well-known issues that MUST
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.
Replace the intake boot o-rings, and possibly the intake boots. Here's the procedure:
Here's an overview of what happens with this particular problem:
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:
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 (for CV carbs)
Or for VM carbs: http://www.thegsresources.com/files/vm_carb_rebuild.pdf
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 up and down as far as reliability. Use as a last resort. (Check their Closeout section for good deals.)
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://www.partshark.com/ (formerly Flatoutmotorcycles.com) - Sometimes slow. Cheapest parts prices, average shipping costs. Don't expect progress updates or much communication. Real Suzuki part numbers. (Note: Chris@flatout is a member of the GSR forum. He has worked hard to improve communication and delivery speed/cost. Lately the reviews have been very favorable.)
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.
And now, a few words about fork springs and rear shocks, from Mr. Griffin. (Comments in parentheses are mine.)
**********Quoted from Mr. Griffin**********
For suspension upgrades, the front end is pretty simple: Progressive brand springs and fresh 15W fork oil. (http://www.mawonline.com has pretty good prices on Progressive products.)
The rear end isn't so simple.
Most of these brands are available in 'eye to eye' and 'eye to
clevis' configurations, in
different lengths for twin shock GS models. The options
are arranged in order of price, low to high.
1. $65-$90 Emgo/MDI: Found all over ebay, and at about every vendor on the internet. General consensus of users seems to be that they are ok quality, but very stiffly sprung. Essentially the bare minimum option from stock. (For example, see: http://www.crc2onlinecatalog.com/rear_shocks.htm)
$120 Redwing: Evidently no longer made, they are
still available at www.loudfastugly.com (and omarsdtr.com).
I've not been able to find anyone who's actually used them, but they
appear to be of halfway decent quality.
3. $210-$230 Progressive 12 Series: Lots of information here and all over the web about them. Most people seem happy with them, several different spring weights available. Available at most online retailers. www.denniskirk.com is a vendor I have had great luck with over the years.
4. $218-$270 Hagon Type A: Seem very similar to Progressive 12 series as far as owner satisfaction, quality of construction, and price. Available in the USA at www.davequinnmotorcycles.com
5. $320-$400+ Ikon 76 Series: Generally pretty highly regarded, lots of options available. From what I've read on the internet, they do seem to be more highly regarded than Progressive. Can be found at http://www.ikonsuspensionusa.com/servlet/StoreFront
6. $419-$589 Works Performance Steel Tracker: Very highly regarded, lots of positive reviews around the internet of Works Performance in general. Customer service (including rebuilding any brand of shock) is very highly rated. More info at http://www.worksperformance.com/html/home.html
There are other options available that can be more expensive, including offerings from Works, Ikon, Ohlins. White Brothers, once a powerhouse in the motorcycle industry, has ceased operations.
(Note from BassCliff: Also check out YSS Suspension at http://www.yssusa.com/products_yss.html.)
I'll tell you what I use and why. I use Rotella-T Heavy Duty 15w40 oil. It is actually diesel engine oil and contains more anti-wear additives, phosphorous and zinc, that these older high-revving engines love. At about $12 a gallon from Wal-Mart, it's less than half the price of many motorcycle-specific oils, and is the best "bang for your buck" value. The synthetic Rotella-T is just fine too, it won't hurt your clutch. If you like, continue reading the links below for everything you ever wanted to know about oil but were afraid to ask.
Here's a great article on motorcycle-specific oil in general.
Here's a 2nd great article, also on motorcycle-specific oil.
Sport Rider Magazine ran a feature awhile back on motorcycle oils as well, and included some testing with detailed results provided. Well worth the read!
Sport Rider "Oil's Well That Ends Well" Part 1
Sport Rider "Oil's Well That Ends Well" Part 2
Richard Wildman (of Richard's Corvair) explains in layman's terms all about grades, viscosity, shear, additives, specs, etc.
Richard's Corvair - Selection of the Right Motor Oil for the Corvair and Other Engines
And, of course, Bob the Oil Guy is a fountain of information.
Additional parts/info links:
New electrical parts:
http://stores.ebay.com/RMSTATOR or http://www.rmstator.com/ - Stators, r/r units, etc.
http://www.ricksmotorsportelectrics.com/index.php - Stators, r/r units, etc.
http://www.electrosport.com/ - Stators, r/r units, etc.
http://www.stockers-ems.com/ - Starters, etc.
http://www.batterystuff.com/ - Batteries, etc.
http://www.bigcrank.com/ - Big Crank Batteries
http://www.odysseybatteries.com/ - Batteries, etc.
http://www.fuzeblocks.com/ - power all kinds of motorcycle accessories.
http://electricalconnection.com/power-distribution/pplate-02202.htm - allows simple and easy installation of electrical components.
A source for "vintage" electrical connector parts:
New Exhaust Systems:
Vance and Hines - http://www.vanceandhines.com/
Mac - http://www.macperformance.com/
SuperTrapp/Kerker - http://www.supertrapp.com/
Laser/Jama - http://laser-exhausts.com/
The Image Works - Old, new, vintage, obsolete, rare graphics and stickers.
Reproduction Decals - Specializing in obsolete and unobtainable decals for vintage motorcycles.
Valve cover and breather gaskets, I recommend Real Gaskets (reusable silicon):
Brake Lines - Stainless steel lines, stock kits, custom kits
Sudco International - Carburetor parts, Classic & Late Model Replacement & Performance Parts, etc.
Jets R Us - Carburetor parts, filters, gauges, etc.
Parts'n'More - Classic UJM parts (i.e. gasket sets): $35 minimum, $5 shipping to lower 48
Motorcycle Accessory Warehouse (Searching by mfg. part#? Leave out the hyphen '-')
Motorcycle Superstore - tires, accessories, apparel (Located in Oregon, fast shipping to the West Coast, free shipping over $75)
Fly-N-Cycle Motorsports - parts, accessories, apparel
All Balls Racing - bearings and seals
Cycle Parts Nation
Ron Ayers Motorsports
CMS-Parts - Parts fiches for non-US bikes
Full Throttle Motorsports
Paint Codes - Use this chart to cross-reference the Color-Rite color codes to Suzuki factory codes.
If all else fails, try this:
Used bike buying checklists:
Lots of good information/pictures here:
The Motorbike Archives - Online motorcycle magazine articles, tests, features, competitions, etc
Motorcycle Info and Accessories - TONS of good info here
Thank you for your
(The unofficial GSR greeter)
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