GS650G problems

[Suzuki mad]

Have a listen to this that I've stolen from another site and tell me what you guy's think.

Its a GS650G imported into the UK from the USA in 1999, currently has 23,500 miles on the clock which is suposed to be genuine. It is in ok condition (needs lots of polishing!) Ridden home by the owner 80 miles and it seemed fine (but perhaps doing 70/80mph did not notice bad running.)

However, around town it feels like it is not running on all 4 cyclinders, will not accelerate very well, idles but does stop occasionally, there is a noticable ticking noise which may be unrelated to the running (coming from inside the tank - normal fuel pump noise?), it does start fine and will start if it stops running. I have run a good supply of redex through it while idling but no difference, so assume it is the regulator/rectifier or something similar as is mentioned in a number of places. It is just a bit expensive if I replace it and find it is still running the same. Any advice would be welcome.

http://www.flickr.com/photos/fred_bear/2792318699/in/set-72157606727436424/

Suzuki mad

[Redman]

Dont have an answer for you, but can comment on a couple things:

- No GS (nor most any mo'cycle of the era) has a fuel pump other than gravity. (That is why the tank is above the engine).

- If you have started it many times, well, then the charging system (including the r/r) must be working fairly well, or you would have a dead battery by now.

To me the sound file didnt sound too terrrible bad, but wasnt very smooth either (but then I am not a tuner either). Problem could be a few little things here and there, from carbs to ignition.
If you are looking into the ignition system, dont overlook the spark plug caps, they do deteriates with time and use.

Someone other than me will have to help diagnose the poor running and the stalling. Might help others diagnos if you can describe anything about how it runs when its first started and cold, and then how it runs after it warms up. And might also help to feel the four pipes as it is warming up, do they all seem about the same or some hotter/colder than others.

PS: I had a new '82 650 for 20+ years, never had a problem with it, so never learnt much about it. But then I got other bikes, '80 & '82 ... and, ah, started learning a few things, just to avoid taking to a service shop.

[Nessism]

Next time the engine is cold, start it up and pay attention to the exhaust pipes; judge if they are getting hot thus the cylinder is firing. From what you describe, and the sound of the video, you may have a cylinder that drops out a idle/low speed.

Standard procedure when purchasing any old motorcycle is to spend some time doing all the maintainence: carb rebuild with new O-rings, new o-rings on the carb boots, valve adjustment, change all the fluids, make sure the R/R is properly grounded, etc. My suggestion is to build a baseline by doing this work so you can build from there. It's pretty much a waste of time and energy trying to diaganose a bike that has been neglected until you bring all the basics up to speed.

[jbs80106]

search other posts for a welcome from Basscliff...

Great set of 'things you should do' when you get a new old bike. I have a 650G as well, 1982.

Good luck!!!

[Suzuki mad]

No not another one of mine.....

Great set of 'things you should do' when you get a new old bike.

Good luck!!!

I would agree they are great things to think about and do when you get a new bike. I've no idea when the person bought the bike 'nor who was the original seller. I'm just trying to get other views from the sound that the owner has posted from people who know about the bikes. I'm just one view and I can be wrong at times.

Suzuki mad

Now you can ask him direct. http://www.thegsresources.com/_forum...d.php?t=131417

[Fred_Bear]

Hi

I am the original poster and GS650 owner. Today I took out the plugs, cleaned them, set the gaps, then gave it a quick run. Photos of the plugs when I got back are at:

http://www.flickr.com/photos/fred_bear/sets/72157606940795640/

The plug positions are looking at them when on the bike.

Regards
Fred

Have a listen to this that I've stolen from another site and tell me what you guy's think.

Its a GS650G imported into the UK from the USA in 1999, currently has 23,500 miles on the clock which is suposed to be genuine. It is in ok condition (needs lots of polishing!) Ridden home by the owner 80 miles and it seemed fine (but perhaps doing 70/80mph did not notice bad running.)

However, around town it feels like it is not running on all 4 cyclinders, will not accelerate very well, idles but does stop occasionally, there is a noticable ticking noise which may be unrelated to the running (coming from inside the tank - normal fuel pump noise?), it does start fine and will start if it stops running. I have run a good supply of redex through it while idling but no difference, so assume it is the regulator/rectifier or something similar as is mentioned in a number of places. It is just a bit expensive if I replace it and find it is still running the same. Any advice would be welcome.

http://www.flickr.com/photos/fred_bear/2792318699/in/set-72157606727436424/

Suzuki mad

[maro]

Okay, I'm confused to who's bike is in questions, etc.

As far as those plugs pictured. Obviously 1 & 4 are running way rich. This could be for a number of reasons. You can adjust the idle/mixture screw to lean them out a bit. But if you have never played with those screws, you will have to take the carbs off to properly take off the stock "cap" above them. (search the site for idle/mixture screw 650G to find more details). And if you are taking the carbs off... Mine-as-well clean them out, get new o rings and re-set the float heights. then get them synched. then play with the idle mixture screws.. I have mine at 2 1/4 out on all of them.

[Suzuki mad]

The bike belongs to Fred Bear, not me. As I said in the first post it was something that I stole from another site. I'm not a GS650G expert only GS1000/1100's.

Suzuki mad

[Nessism]

Idle mixture screws are for idle, they will not have a meaningful effect on plug color. The rich mixture is most likely being caused by running the bike with the choke on since the jets are all plugged up. Another possibility is leakage on the float needles or even weak spark. Shooting in the dark since the maintanence of the bike is not up to date.

[maro]

Idle mixture screws are for idle, they will not have a meaningful effect on plug color. The rich mixture is most likely being caused by running the bike with the choke on since the jets are all plugged up. Another possibility is leakage on the float needles or even weak spark. Shooting in the dark since the maintanence of the bike is not up to date.

really, I though I have learned otherwise. what does meaningful effect mean. I set my idle mixture screw for highest idle, but have since tweaked them, in or out depending on plug color and performance.

[Nessism]

really, I though I have learned otherwise. what does meaningful effect mean. I set my idle mixture screw for highest idle, but have since tweaked them, in or out depending on plug color and performance.

The pilot screws are for idle and slightly above. They don’t have much effect above this point and plug color since the bike doesn’t spend much time running off this circuit - the main jet and pilot jet are far more meaningful.

[Clayton!]

I had the same problem a while back with my 650g, check your carb vent tubes, take them off, check for any blockage and remeber to angle them upwards into the cavity below the tank. If those are mistakenly plugged, the bike will run rough like that, but not die usually. Hope this helps! Also, how the heck did he start that bike without the clutch held in? I've got a 81' 650g that you can not start unless the clutch is held in, modification?

[themess]

Sounded to me like a valve was a bit loose.

[duaneage]

I would start with checking the intake boots between the carburetors and engine by spraying a little WD-40 around them when the engine is running. IF the idle speed increases the o rings inside are bad, common problem.

Next up check the screen in the tank on the petcock. If covered in rust or dirt clean the tank out with phosphoric acid. Don't get it on the paint!

while the tank dries out, spray carburetor cleaner through the fuel inlet while allowing the waste to run out of each fuel bowl. Remove the screw at the bottom taking care to catch the gas that comes out. You can start the bike and allow it to drink most of the gas first. Then spray about 20 seconds of carburetor spray through, draining each carburetor one at a time. Replace the bowl screws and move on to the next carburetor. As you do this carburetor cleaner will accumulate inside and clean out the internal bits. When done drain all four and replace the screws,

Now put the tank back on and add clean fuel and try again. This does not substitute a proper carburetor cleaning but then again rebuilding the buggers is a lot of work and you may not be up for it. This way you can clean the tank, remove any rust, clean out the carburetors where it counts, and hopefully remove any varnish that has accumulated,

Nice bike, looks better than mine, definately a keeper.

[boathead]

Standard procedure when purchasing any old motorcycle is to spend some time doing all the maintainence: carb rebuild with new O-rings, new o-rings on the carb boots, valve adjustment, change all the fluids, make sure the R/R is properly grounded, etc.

mr. nessism, can you expound on this? more particularly, can you expound on the "etc."?

i just got an 850G that is not running, with the carbs in a box. my intention is to, at my snail pace, start going through things, and learning how things work. i'd love a list of things that this newbie should do/look into.