Need help with my '82 GS850G

**Steve** · 06-22-2007, 03:46 PM

First of all, find another mechanic. "running a couple tanks of super" will NOT clean anything in the fuel system. :shock:

"Super" gas has higher octane to offset pre-ignition, usually caused by heat. In high-performance engines, they get the higher performance by raising the compression ratio, which raises the heat. That extra heat will sometimes set off the fuel mixture before the spark ignites it. "Super" or "premium" gas will reduce the likelihood of pre-ignition.

What you need is a good carburetor or fuel injection cleaner run through for a couple of tanks. One of the best is SeaFoam. In your case, it sounds like I would add just over half the can, which is MUCH stronger than they recommend on the can, fill the tank and ride it until you hit the reserve on the tank. Fill the tank and run it for at least another couple of miles before parking it.

If that does not work, you will have to resign yourself to a good, old-fashioned carb removal and dipping session.

.

**Nessism** · 06-22-2007, 04:18 PM

Originally posted by spanky88

Also, when I'm on the highway, she'll suddenly burst into speed as if she's running the way she's supposed to, and then go back to the former status. This occurs regularly.

Jim

This comment makes me wonder if the bike is running on all cylinders? The problem could still be ignition related. The plug caps sometimes develop excessive resistance, NGK makes nice replacements for cheap, and/or you might have a bad coil. Not sure but something to look into.

**BassCliff** · 06-22-2007, 04:55 PM

Mr. spanky88,

I should probably be quiet and let the grownups talk. But I want to try out my new toy. :-D

I'm looking at the troubleshooting guide in my brand-new "used" Suzuki GS850 shop manual. (I didn't realize that these books were hot pink in color! I'm going to have to get these pages into a loose leaf binder.) For both of your symptoms a valve clearance check/adjustment is suggested. This procedure is usually followed by carb work (rebuild, clean, balance, adjust, etc). Also, make sure your airbox is sealed up tight. These old 850's need new weather stripping around the airbox side covers and the top of the air filter cage. There should be no air leaks at the carb boots either.

Also mentioned in the manual for these type symptoms:
Ignition timing or improper gaps on contacts and spark plugs.
Clogged fuel path: petcock, debris in tank, fuel lines, vacuum line, etc

I'm sure one of the gurus will offer more specific help but usually it's valves, then carburetors, in that order. There are two ignition coils, one for cyls 1+4 and the other for 2+3. One of them may be flaky.

Thank you for your indulgence,

BassCliff

**bwringer** · 06-22-2007, 09:08 PM

I agree that you need to find another mechanic (hint: look in a mirror to locate the only mechanic who's going to care enough to actually fix the problems).

All the above is excellent advice -- you have the classic signs of intake leaks, plus possible ignition problems. And you'll definitely want to check the valve clearances before you do anything -- the proper clearances are very small, and it's common to find these way out of whack on neglected machines. The bike will never run right and may even damage itself badly if valve clearances are neglected.

The ignition problem could be as simple as a broken wire or one bad coil -- one coil fires the #2 and #3 cylinders, and the other fires #1 and #4.

As far as the intake leaks, you now get to participate in the first rite of passage for all modern 850G owners -- sealing the chrome covers on both sides of the airbox with foam weatherstripping. Feel the bond of 850G brotherhood...

You'll also need to seal the top of the air filter with weatherstripping in much the same way. You may even find the remains of the original decayed foam. Basically, air should only be able to get into the airbox via the snorkel in back and the vent holes in the bottom, and it should not be able to bypass the air filter.

Next, you very likely need to replace the intake boot o-rings, and possibly the intake boots. Here's the procedure:

Suzuki GS Motorcycle Illustrated Repair and Maintenance

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:

index

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

Whatever you do, do NOT waste your money on carb rebuild kits. They are pure junk. Clean and re-use all the metal parts, replace the o-rings, and you might also need to replace the float bowl gaskets.

Congratulations! You are now riding a beautifully performing vintage machine.

**pvtschultz** · 06-22-2007, 09:47 PM

Well stated...Beautiful actually!

Carl

**BassCliff** · 06-23-2007, 12:37 AM

Mr. bwringer,

Another excellent post that I'll copy/paste into my personal repair journal. Many thanks.

Thank you for your indulgence,

BassCliff

**spanky88** · 06-23-2007, 09:46 AM

Wow, thanks for all of the awesome help/suggestions! BassCliff - your post was a riot!

bwringer - I am feeling the BOND!

*I neglected to mention that the plug are new and the carbs were recently cleaned as well. *

I have a strong feeling that the problem lies in both/either the valves and the ignition timing. Thanks for conforming my suspicions - I'll be trying all remedies you list to get it resolved, and will repost my results here.

Thank you all again!

FYI - this is my 4th Suzi. Started with a GS450, then a GS550, jumped up to the big boys with a GS1100GK (she was a sweet lady) and now the GS850G after an 8 year hiatus while I lived in NYC.

**captainbellybuster** · 06-23-2007, 05:56 PM

Hi Jim, I had a similar problem with my 1100G. It was really hard to pin down. Does yours have mechanical timing advance, or is it done electronically in the igniter box? Mine has the electronic advance & this turned out to be the problem. Just another thought for you. Cheers, Paul.

**spanky88** · 07-03-2007, 08:22 AM

bwringer: after visiting your excellent pages I've decided to go your route and replace the O-Rings and the intake boots. I notice you mention that the IB's should be good for 20 years, and as my bike's an '82, I might as well replace them while I have everything off. Problem is- I CAN'T FIND REPLACEMENTS! Sorry for shouting, but I've been Googling for two days straight, on top of ebaying, Old Bike Barning, and Bike Banditing. -To no avail. Any advice on where I can find these? Thankyouthankyouthankyou.

**JTsGS650** · 07-03-2007, 08:43 AM

Originally posted by spanky88

bwringer: after visiting your excellent pages I've decided to go your route and replace the O-Rings and the intake boots. I notice you mention that the IB's should be good for 20 years, and as my bike's an '82, I might as well replace them while I have everything off. Problem is- I CAN'T FIND REPLACEMENTS! Sorry for shouting, but I've been Googling for two days straight, on top of ebaying, Old Bike Barning, and Bike Banditing. -To no avail. Any advice on where I can find these? Thankyouthankyouthankyou.

Intake boots (or intake pipes as shown in the 'fiche) are $18.53 each at

Home Flat Out Motorsports Indianapolis, IN (317) 890-9110

http://www.flatoutmotorcycles.com

Home Flat Out Motorsports Indianapolis, IN (317) 890-9110

Orings are $2.28.

**bwringer** · 07-03-2007, 10:10 AM

The intake boots and o-rings are not available as an aftermarket part -- you have to order them from your favorite Suzuki parts source.

Bikebandit is one such source -- click the "OEM Parts" box on their home page: http://bikebandit.com and go from there. The intake boots and o-rings are listed on the Cylinder Head parts diagram. I think they call them "PIPE, INTAKE" or something like that.

BB uses their own parts numbering scheme to discourage comparison shopping, but you can also type in the Suzuki parts numbers I provided on their parts number search box on the left to translate to Suzuki part numbers. Make sure you get two left boots, two right boots, and four o-rings.

Bikebandit is not quite the cheapest parts source, but they are consistently the fastest -- you should have your parts within 5-7 business days. They also have very low shipping charges -- usually only $4 - $6.

http://flatoutmotorcycles.com/fiche_select.asp is another good source, and has the best prices (about 20% less than BB), but they tend to be slow (2-3 weeks usually) and they charge waaaaay too much for shipping -- at least $12 and often much more, even for small orders, and you don't see shipping charges until you've already ordered. They really need to fix that.

I tend to use BikeBandit unless I'm ordering a couple hundred dollar's worth of parts and I'm not in a hurry.

**rustybronco** · 07-03-2007, 10:45 AM

check mrcycles.com and see if the prices are in line. it took 1 week for my x's atv parts to get here.

http://www.mrcycles.com/fiche_sectio...1982&fveh=2144

**spanky88** · 07-07-2007, 08:18 AM

To All:

I took the leap - parts are now all ordered. Thanks again to all for the advice/info, and especially bwringer for that invaluable chunk of info. Updates on my progress to follow.

Spanky

Need help with my '82 GS850G

Need help with my '82 GS850G

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