help, sometimes seems like it starves for gas

[tim999]

Hi I am new to this site, and i just want to say its been a great resorce.
I have a 1985 GS550L, I just bought it a month ago from someone who had the bike sitting in a garage for 10 years. its it great shape no rust. only 6500 miles. tank was creamed. I just rebuilt the carbs and had it sync. I been having a strange problem. It runs good, but when its cold or sometimes for no real reason if you try and give it any gas at all it dies. Then will start up again just fine when i open the choke. This has been happening before and after the carb rebuild. I just now replaced the petcock with a manual Z1 model and capped the vacc. Still having the same issue. any ideas? any help is appreciated thanks.

 

[BassCliff]

Hee Haw Howdy!

Hee Haw Howdy!

Hi Mr. tim999,

Did you set the valve clearances before you synced the carbs? Are you using an inline fuel filter? Here's your very own mega-welcome! :dancing:

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************
Every GS850 (and most other models) 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.
***********************************
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

***************************************
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
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
Salvage/Used
http://www.ricepaddymotorcycles.com
http://www.ozpowersports.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
http://www.bikepics.com
Basic motorcycle maintenance/repair:
http://www.dansmc.com/mc_repaircourse.htm
Online Clymer manuals:
http://search.ebscohost.com/ Click on "Small Engine Repair" then "Motorcycles". User=library, password=library. Note: This link may not work if you are on a school campus.

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)

 

[Steve]

When you rebuilt the carbs, how did you do it? Did you follow the suggestions in the carb rebuild series? Too many guys try to just spray out what they can see with some carb cleaner and install a "rebuild kit", but that's not what it takes to properly refresh these carbs. You might also need to check the condition of the intake o-rings. These are the items that seal the intake tubes to the cylinder head. If they leak, it will wreak havoc on your fuel mixtures, creating a lot of problems.



By the way, Cliff, that 4-minute response is a good improvement.

.

 

[tim999]

Thanks for the big welcome. I added some pics to my profile.
first I did not check the valve clearence before the carbs were sync.
The rebuild of the carbs was done thorough. I also put in new floats and needle valves. (OEM)
I am using an inline filter.

My friend is a motorcycle mechanic, mainly harley but has worked on metric also. He just hasnt worked on bikes this old. He helped me with the carb rebuild and checked the intake o-rings and to the air box.

forgot to add...when I first got it back together it ran like this, then I took apart the petcock and saw it was bad. But I cleaned it and put it back together and ordered a rebuild kit. weird thing was It ran great no problems. when I got the rebuild kit i used it and replaced the dry rotted diaphram and seals and it ran like crap again. So step 4 I bought a new petcock from Z1 (manual), capped the vaccumm and it still runs like crap but a little better. could air getting into a fuel line or the vaccum not being sealed all the way be a reason?

 

[tim999]

solved

solved

The problem was the slides. After sanding them down some, it runs great now.

 

[Nooner]

warm up time?

warm up time?

I have a similar problem. '81550GSt
In cooler weather it seems to be less responsive on the throttle for the first 15minutes or so. I'm not sure how to describe this except that it seems to lag somewhat. I use the bike to commute 20 miles each way over some fairly steep and long hills.
I've been told that it takes some time for these bikes to warm up, is that true?
I suspect that the real issue is in the carbs and fuel line. My bike was also in storage for a few years and I wouldnt be suprised if it seriously needs a good cleaning rebuild. I will attempt this when the season ends but have some reluctance because my mechanical skills have the depth of a tea spoon. Thank you for the links in the above posts.

 

[bothebrave]

sanding of the slides

sanding of the slides

What did you use to sand the slides?

 

[trippivot]

try the next hotter spark plug for a quicker warm up in colder weather before messing with the carbs. they might be tuned right at full temperature.

I have a similar problem. '81550GSt
In cooler weather it seems to be less responsive on the throttle for the first 15minutes or so. I'm not sure how to describe this except that it seems to lag somewhat. I use the bike to commute 20 miles each way over some fairly steep and long hills.
I've been told that it takes some time for these bikes to warm up, is that true?
I suspect that the real issue is in the carbs and fuel line. My bike was also in storage for a few years and I wouldnt be suprised if it seriously needs a good cleaning rebuild. I will attempt this when the season ends but have some reluctance because my mechanical skills have the depth of a tea spoon. Thank you for the links in the above posts.