GS550L wont run right

[deerejohn]

I just bought an 82 GS550l from a local dealer and it was in non running condition. The bike has only 6,400 original miles and is in great shape. The gas doesn't smell that old, but it would not run. I removed the carbs and disassembled and cleaned all the passages. I have seen the procedure to clean these and followed it.However, I did not remove the idle screws because i did't know that I could(there is a cap over the holes).

Anyway, I assembled the carbs and installed them on the bike and was able to start it. It didn't run very well at first but got better after a while. I the took it for a ride and had decent acceleration at first, but then it bogged down right away like its not getting enough gas. The bogging down is somewhat cured wen I turn on the choke or stay at part throttle.

I think its not getting enough gas, but don't know what to check for.
Also, the idle is very inconsistent. Sometimes its barely running and other times its racin at 3000 rpm

I have good compression 125psi
Plugs replaced
Good spark to each cylinder

Does anyone have any idea what I can do next?

[GSJohn]

The petcock is vacuum operated and if the diaphagm is leaking it may not open all the way to provide enough fuel and also gas from the tank can bypass the #2 carb and get sucked directly into the cylinder.

[Nessism]

Your intake pipe "boot" O-rings are most likely leaking allowing air to be sucked into the engine. This is one of the most common problem with old GS bikes and causes the mixture to run lean and causes a hunting idle.

You should also check out the petcock as John alludes. Pull off the fuel line to the carbs and replace with a section going to a gas can. Also, get a section of vacuum line and hook that up to the vacuum port of the petcock. First turn the petcock to the "prime" position; gas should flow easily out of the fuel port. Turn the petcock lever back to "on"; gas should stop flowing. Now suck a vacuum on the vacuum line to the petcock and gas should start flowing again - nice full stream of fuel. Same business with the petcock in the "Res" position. If you have vacuum bleed-down, the petcock is bad and should be replaced. Similarly, if the fuel flow is not full, the petcock is bad. Replacements are available from dealer sources

While the carbs are off to replace the boot O-rings I suggest replacing the various o-rings in the carbs with a kit from cycleorings.com. It's well worth the effort.

Good luck and enjoy your new toy.

[deerejohn]

Thanks for the info guys.

While the engine was running last night, I sprayed carb cleaner at the intake boots and the rpm changed, so I do have an intake leak.

I know I am getting fuel to the carbs because I ran a hose from the tank to a bowl and it pulsed very well while cranking.

How would I check to see if fuel is bypassing #2 carb?

should I remove the idle screws?

[doctorgonzo]

Probably no need to drill out the caps on the idle screws unless you intend to put a jet kity in the carb (in which case it will come with everything you need to do that). I think a lot of people have a hell of time getting those idle screws right once they mess with them.

[Nessism]

If the petcock is working properly, there will be no issue with the #2 carb – that’s only when the petcock is leaking internally.

Regarding the pilot screws, your 550 will run MUCH better with these screws set to about 3-3.5 turns out from lightly seated. Standard process is to adjust them to about 2.5 turns and then tweak them to achieve the highest idle. Some other models may run at 2 or 2.5 turns, but the 550 likes more (factory setting is about 2 turns).

No disrespect intended but the fact that you did not remove the pilot caps makes me concern for how clean you got the carbs to begin with. GS carbs must be surgically clean or the bike will not run right, and you can not get the pilot circuit clean with the screws in there. Also, the internal carb o-rings dry out with age and should be renewed, not only on the intake boots.

Lastly, did you check the air filter? They deteriorate and start to crumble after a while.

[deerejohn]

Thanks for the input. I was in too big of a hurry. I ordered all the orings and will follow your advice.

Why I don't understand is why last night I coudn't even get it to start after a while. With choke on or off the bike just cranked and cranked. IIt would start with propane added, but not on its own. Sometimes it would start and sometimes it would not. Would the intake orings have that big of an impact on it?

I will remove the carbs and perform a more thorough job.

[BassCliff]

Hey howdy hey!

Hi Mr. deerejohn,

After a GS has been sitting for a long time there are just a few kinks to work out. Then you will have a reliable, bullet proof motorcycle. With the help of other kind folks on this forum, I put together a little thing that should have a lot of the information you need to get you started. I call it my 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 here 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**********************
Here are some extra 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/

The Rice Paddy (salvage/used)
http://www.ricepaddymotorcycles.com
Ron Ayers Motorsports
http://www.ronayers.com
MR Cycles
http://www.mrcycles.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)

[deerejohn]

Dumb question.

The link below has a picture of one of my intake boots.

Is it bad? If so, Where can I get one from cheap and fast? Should I replace all 4?

http://www.putfile.com/pic/7914872

[BassCliff]

How soft is it?

Hi Mr. deerejohn,

Here is your intake boot:



Is your intake boot this pliable?



Or is it more like this one?




While you have the boots off to replace the O-rings, check the boots for pliability. If they're too hard and dry they could start cracking and cause air leaks. This is not good for GS motorcycles and other living things. Mr. bwringer has an excellent guide for replacing these parts. His website is http://www.bwringer.com/gs . Give it a look.

Thank you for your indulgence,

BassCliff

[deerejohn]

Mine are half way between hard and soft. Some carb spray told me that either th boots or intake orings are leaking but I'm not sure exactly at this time.

[suzukizone]

GS550L wont run right

Having spent a lot of time rehabbing my '81 GS850 I found each of these steps made a noticeable difference. All were done separately so I wasn't seeing improvement from several fixes combined. Maybe this can help- just saying these helped me out.

1, Replace all intake boots from air box to intake side of carbs.

2. Rebuild carbs & replace pilot jets even tho they looked good.

3. Carefully set float level.

4. Carefully synch carbs.

5. Replace Manifold O rings. My manifold boots were still pretty soft or these should be done as well.

6. Carefully getting good plug read by fine tuning pilot screw.

We have also found bikes sitting for as little as 2 weeks will have many probs including not running with choke off, backfiring, poor low end performance, no-start, and others due to phase separation of ethanol gas. You can learn lots about this by plugging "Phase seperation of Ethanol Gas" into search engines.
Once fine carb passages are plugged not much to do but tear them down & clean preferably in ultrasonic or chemical cleaner then very careful blowing out of all passages, You can also use a water pik to be certain the fine passages are clear. Just spend lots of time with goods sounds on.

Finally as far as I know the only product that seems to hold the ethanol fuel together is STARTRON by STARBRITE. Sold at boating stores. I heard the boating shops have been suffering with these carb problems. Good for any fuel going into carbs that sit a bit.

I heard that soaking rubber parts in diesel fuel can soften them but I'd take that as rumor unless you know better.

Anyway just my two cents for what it's worth

DH