Handling problems

[phil68]

I am fairly new to this but having read the posts it seems like my kind of group.
I have recently bought a 1979 GS 850 GT which was off the road for a few years.
After cleaning all the crap out of the carbs and petcock it runs well.
I replaced the head bearing as it had a notch, and put on new fork seals,rear shocks and a front tyre.
The fork oil and and springs are as per the book , but it is terrible on roads which have any wear on them, it follows evey line and undulation.
It corners well to the left but it seems to turn into right hand bends and feels very twitchy.
I have got a new rear tyre on order, but any help would be great.
I use the bike to travel 170 miles each day and could do with enjoying it more than I do.
Also what tyre pressures do you run, I have Avon tyres.

cheers

phil

[BassCliff]

Hee Haw Howdy!

Hi Mr. phil68,

Not to pick nits, but if yours is a '79 then it is a GN. The '80s are GTs. Some tires are better than others at "ignoring" road imperfections. I've heard that the rear tire can affect the handling just as much, if not more, than the front tire. Do you use air in your forks for preload? Is it balanced? Do the fork springs need replacement? They can get "tired". The Progressive springs are a favorite around here. Have you replaced the front wheel bearings? Avons are good tires. I run about 32psi in the front and 35psi in the rear. And now, before I forget, here is your very own mega-welcome! \\/

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 if your bike uses shims for valve adjustments, send an email to Mr. Steve requesting a copy of his valve adjustment spreadsheet.

These 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**********************
Additional parts/info 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/

For valve cover and breather cover gaskets, I recommend Real Gaskets (reusable silicon):
http://www.realgaskets.com
The Rice Paddy (salvage/used)
http://www.ricepaddymotorcycles.com
Carolina Cycle
http://www.carolinacycle.com
Ron Ayers Motorsports
http://www.ronayers.com
MR Cycles
http://www.mrcycles.com
Moto Grid
http://www.motogrid.com
If all else fails, try this:
http://www.used-motorcycle-parts.org/
Used bike buying checklists:

http://www.amadirectlink.com/roadride/Riderresc/checklist.asp

http://www.clarity.net/~adam/buying-bike.html
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)

[49er]

I am fairly new to this but having read the posts it seems like my kind of group.
I have recently bought a 1979 GS 850 GT which was off the road for a few years.
After cleaning all the crap out of the carbs and petcock it runs well.
I replaced the head bearing as it had a notch, and put on new fork seals,rear shocks and a front tyre.
The fork oil and and springs are as per the book , but it is terrible on roads which have any wear on them, it follows evey line and undulation.
It corners well to the left but it seems to turn into right hand bends and feels very twitchy.
I have got a new rear tyre on order, but any help would be great.
I use the bike to travel 170 miles each day and could do with enjoying it more than I do.
Also what tyre pressures do you run, I have Avon tyres.

cheers

phil

Hi Phil

Welcome to the GSR. You will recieve the official welcome in due course!!

Your '79 is a GS850GN. If it's a '79 it will have a kick starter, VM (slide carbs) and a round front master cylinder, amongst many other oddities.

Re-check the front end since your stearing head bearings were notchy. If it turns well in one direction, it often indicates that the bike has had some crash damage in the past. My 1100G parts bike has been dropped by a PO and has the same notchy feel. The notchy feel can also come from rust forming on the bearing race through poor lubrication and years of inactivity.

After 30 years, your stock front springs will have become saggy. The solution is to fit some progressive springs and 15 grade fork oil to stiffen things up.
My '79 had gas over oil shocks. I don't use the air since fitting the progressives. One less air pressure to keep an eye on and performance is consistant!
You will find that your shaftie will naturally turn better to the left because of the extra weight of the shaft drive on that side of the bike. This tendancy can be improved by running a 4-1 exhaust. They exite to the right side and partially counter the diff weight.

I run Pirelli Sport Demons at 34psi front /38psi rear tyre pressures on my bike riding without a pillion.
Until you upgrade your front end, try running 36psi on your front tyre. That will help kerb the bike from tracking so much on uneven surfaces.
They are a great model, once everything has bveen sorted.

[49er]

I was pipped at the post. At least you got the timely official welcome.

[bwringer]

It sounds like you may have the front end bearings too tight. Does it sort of wander around when you're coming to a stop? That's the symptom I tend to notice first in these situations.

Also, which Avon tyres do you have? The AM26 RoadRiders are excellent, and very good at resisting the pull of pavement irregularities. If you got an earlier leftover Avon design, then I dunno.

Let's see... is your tyre pressure REALLY low? You want to run your front tire/tyre at around 32-36psi. If it's too low, it'll tend to follow things in the road. Try a different pressure gauge -- these sometimes go bad or are calibrated wrong.

The other thing to check is the rear swingarm bearings. These are extremely durable conical bearings on a GS850, but they may have been set up too loose.

[bonanzadave]

It sounds like you may have the front end bearings too tight. Does it sort of wander around when you're coming to a stop? That's the symptom I tend to notice first in these situations.

Ill second that motion. Back off the big spanner nut in 1/8" increments and go test ride.

[Steve]

You will find that your shaftie will naturally turn better to the left because of the extra weight of the shaft drive on that side of the bike. This tendancy can be improved by running a 4-1 exhaust. They exite to the right side and partially counter the diff weight.

Your're kidding, right?

I thought the "extra weight of the shaft drive" was already offset by the weight of the clutch assembly on the right side of the engine and the weight of the brake fluid in the master cylinders, both of which are on the right side.

Yeah, I know this makes just about as much sense, but I am only pulling the other leg. :-\"

.

[49er]

Your're kidding, right?

I thought the "extra weight of the shaft drive" was already offset by the weight of the clutch assembly on the right side of the engine and the weight of the brake fluid in the master cylinders, both of which are on the right side.

Yeah, I know this makes just about as much sense, but I am only pulling the other leg. :-\"

.

Yeah, the site needs more humour.

[argonsagas]

A number of other things have already been mentioned, but a simple one has not yet been posted.

Put the bike on the centrestand and check alignment.

This is really simple. You need to be sure the ground you are on is level, then put the bike up.
Point the front wheel straight ahead.

Pin a chalk-line type cord ahead of the bike , in direct line with one side of the front wheel.

Bring the taut cord back to the wheel and very close to the tire.

If you have measured this correctly, if you pull the cord closer to the tire from behind the tire, the cord should touch front and back parts of the tire at the same time.


Rotate the wheel one half turn and repeat.

Do the same with the other side of the wheel/tire. This will verify your first effort and will also verify if you have a tire that is laterally out-of-round.


If you find that the cord touches the front part of the tire first on one side, and when checking the other side you find the cord touches the rear part first, then alignment is needed.



Now stretch the cord back farther and do the same with the rear wheel.

At the same time as the cord is contacting BOTH front and rear of the rear tire, do a careful measurement of the space between the cord and the front tire, which is narrower than the rear. The space should be constant between the point at which the cord passes the rear portion and the front portion of the tire..


Do the same on both sides.

[bwringer]

A number of other things have already been mentioned, but a simple one has not yet been posted.

Put the bike on the centrestand and check alignment.

This is really simple. You need to be sure the ground you are on is level, then put the bike up.
Point the front wheel straight ahead.

Pin a chalk-line type cord ahead of the bike , in direct line with one side of the front wheel.

Bring the taut cord back to the wheel and very close to the tire.

If you have measured this correctly, if you pull the cord closer to the tire from behind the tire, the cord should touch front and back parts of the tire at the same time.


Rotate the wheel one half turn and repeat.

Do the same with the other side of the wheel/tire. This will verify your first effort and will also verify if you have a tire that is laterally out-of-round.


If you find that the cord touches the front part of the tire first on one side, and when checking the other side you find the cord touches the rear part first, then alignment is needed.



Now stretch the cord back farther and do the same with the rear wheel.

At the same time as the cord is contacting BOTH front and rear of the rear tire, do a careful measurement of the space between the cord and the front tire, which is narrower than the rear. The space should be constant between the point at which the cord passes the rear portion and the front portion of the tire..


Do the same on both sides.

On a shaftie, what will this accomplish?

Or do you suspect a badly bent frame?

[tkent02]

Your're kidding, right?

I thought the "extra weight of the shaft drive" was already offset by the weight of the clutch assembly on the right side of the engine and the weight of the brake fluid in the master cylinders, both of which are on the right side.

Yeah, I know this makes just about as much sense, but I am only pulling the other leg. :-\"

.

Don't forget the Coriolis Effect.
You are in the Northern Hemisphere, right?
So everything that moves is always trying to turn right.
For the Kiwis in the gallery everything that moves wants to turn left.
For the Aussies, have another beer.

[49er]

Don't forget the Coriolis Effect.
You are in the Northern Hemisphere, right?
So everything that moves is always trying to turn right.
For the Kiwis in the gallery everything that moves wants to turn left.
For the Aussies, have another beer.

Now we're cooking with gas!

Ah, Aussie beer. Very chemical in taste compared to most Kiwi brews. I did get addicted to VB though whilst I was there. It did take six years to decide which brew I liked best though!! That was one great working holiday.
After a few VB's, the Aussies wouldn't know/care which way the bike turns best!