Valve and Carb question

[mopar19]

Hey all,
1981 gs850gl. I took my carbs apart, cleaned and bought the O ring set and reassembled. With the the fuel screw all the way set down, how many turns to open it up? Also, valves were all way to tight. Took out my shims and all were 2.65 except for one, 2.55 and I got a feeler guage up to 00.4 to fit. I ordered new shims from z1 (2.50 and 2.55) 8 oF them each. Do you think I should redo all the shims with the 2.50 or 2.55?
Thanks for any help!

[Dave8338]

Try 1.25-1.5 on the fuel screws and as far as the shims are concerned...error on the side of loose as they will tighten over time.

[Steve]

Actually a good starting point for the fuel mixtures screws is two full turns out.

You bought 8 of each size shim? Best way to be sure is to try the 2.55 shim in each of the positions to see what clearance you have, then calculate your desired shim size from that. That will prevent buying too many shims at one time.
I find it interesting, however, that 7 out of 8 had the same size shim.
Nothing wrong with that, it just seldom happens.

.

[Dan Ruddock]

It is common practice on this forum to count fuel screw turns out and adjust air screws to get idle mixture correct. I believe this is the wrong way to do it. I believe the opposite is correct, count air screw turns to a fixed amount and adjust fuel screws to adjust idle mixture. I could go into a long explanation as to why but for now just let this roll around in your heads. Dan

[bwringer]

It is common practice on this forum to count fuel screw turns out and adjust air screws to get idle mixture correct. I believe this is the wrong way to do it. I believe the opposite is correct, count air screw turns to a fixed amount and adjust fuel screws to adjust idle mixture. I could go into a long explanation as to why but for now just let this roll around in your heads. Dan

For starters, this bike has CV carbs... not the VM carbs you're referring to.


And I concur that two turns out is a good starting point for the mixture screws on an '80+ GS850.

[Dan Ruddock]

For starters, this bike has CV carbs... not the VM carbs you're referring to.

Good point, I does help to read all of the op. Dan

[mopar19]

Thanks for the responses.

[BassCliff]

Hee Haw Howdy!

Hi Mr. mopar19,

I usually see new members before they have 9 posts, but I've been busy lately. Mr. Steve has an excellent spreadsheet to help you configure and keep track of shims in your motor. Send him an email for your very own copy. It's very handy. My little BikeCliff website contains a collection of pictorial maintenance guides and manuals that you are welcome to. Other than that, I'm just going to give you my usual 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 Excel spreadsheet that helps you keep track of clearances, shim sizes and other service work.

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)

[lurch12_2000]

Hey all,
1981 gs850gl. I took my carbs apart, cleaned and bought the O ring set and reassembled. With the the fuel screw all the way set down, how many turns to open it up? Also, valves were all way to tight. Took out my shims and all were 2.65 except for one, 2.55 and I got a feeler guage up to 00.4 to fit. I ordered new shims from z1 (2.50 and 2.55) 8 oF them each. Do you think I should redo all the shims with the 2.50 or 2.55?
Thanks for any help!

I assume you meant .04mm? And be sure to stay with mm and not inches otherwise it's easy to get messed up.
Is only one valve at .04mm(the 2.55 one) and all the others are to tight?
Did you try to swap the 2.55 into one of the 2.65 to get a reading? Don't worry about the 2.65 being put in the 2.55 location as this is only temperary to get an idea whether your newly ordered 2.55 are too much of a drop (2 sizes worth).
The 2.50's would be a drop of 3 sizes which would be unusual.
Advice after the fact is no help, but you shouldn't order 16 shims before knowing what you need.
Heads up- those sizes would be a very common size shim for other forum users, who will be wanting them on their next valve adjustment, including me, so you could work something out to unload or swap them. I've sent un-needed ones to other forum users and swapped with others. One shim in a regular envelope and one stamp (41 cent) is all you need to send it out to someone. Not sure if 2 shims require an additional stamp, but tape them to piece of light cardboard folded over before putting them into the envelope.

NOTE: do NOT turn the engine over with the shim removed and leaving the bucket empty!! you can swap 2 shims at the same time by picking 2 valves to hold open at the same location when turning the crank by hand. Zip ties are very handy if you don't have the shim tool for this.

[mopar19]

yea, only one valve was within spec. I was able to get a .003 feeler guage in there. I swapped the 2.55 (which is the one that was within spec) with another and was able to get the .003 feeler in there. All the rest I couldn't even get a .015 in there. So I'm just assuming the 2.55's will work, and if not I just got the 2.50's just to be on the safe side. I didn't mind getting all the shims. I just want to get it done and get out there and ride. ..