GS850 not running right, carbs? Need help soon

[GregM.]

FINAL UPDATE –
The new battery solved it. Thanks for the education I always figured that if the battery was strong enough to start the bike in cool (around 40 degrees) weather… that it was in pretty good shape !

I did not know that when the bike is all warmed up, there is additional resistance in the electrical system (basically the coils ?) and that this requires even MORE juice from the battery to start the engine.

A few of you mentioned this possibility – and THANKS, you were right on !
I realize ALL the other advice is important too… and would like to make sure that it’s up to par as well.

THANKS for the quick and very helpful info.

UPDATE - Thanks a ton for the awesome help so quick! I think that I have enough info now. I put in a new battery today, and it already seems better... however it rained most of the day... so I didn't get to really repeat past situations. But with everybody's help, I feel better about getting this completely sorted out. I will post back here later with whatever the final issue really was
I appreciate it... Greg

Hi, I have a 1980 GS 850G - all stock, no rust, no accidents, never left outside, it's in nice shape and has 29000 miles on it. I've owned it 5 years (maybe a bit longer), and have been a regular at this site off and on since then (was addicted to this site years ago). I am NOT a mechanic (I've only done basic upkeep), but I've always liked riding motorcycles, and love my 850.

I had a guy rebuild the carbs, maybe 4 years ago, replaced most all the parts, in and around, the carbs at that time. The bike ran fine. However for the last couple years I have only been doing "maintenance rides". I take the 850 out for a 30 to 45 minute freeway ride, approx 3 times a month, year round. I feel this keeps the battery in shape, and all the fluids, and seals, and everything working pretty well. And I haven't had any problems with the bike.

NEW issue, that I would like some detailed info on soon please.

A month or so, I started riding my 850 a bit more, have been commuting to work (on dry days) and running errands on her. The new issue, is that several times recently, when I just ride to the store, do a little shopping, come out to ride home, SHE WON'T START. I've had to wait 30 minutes, and up to an hour one time. And then... she WILL start!

This problem may have been there for some time... but I never noticed it because there was always a week or two between starting it (go for my maintenance ride, and then shut it off). But now, if it's just parked a short while... and then you try to start it... no go! Until some time has passed (30 to 60 minutes) and then my 850 will work like normal.

I would love to hear as much info as possible as to all the different things that could be wrong. THANK YOU very much for your time and thoughts!

Greg M.
Seattle, WA. USA

 

[Guest]

I'm thinking you have a short somewhere. Could be a bad ground. The other week mine did something similar (would start after a minute though). Traced the short to a connector in the headlight, it was just a bit loose. It's been sitting for some time, you might do yourself a favor and go through all the grounds and all the connectors and clean them up with contact cleaner and lube them with dieletric grease. Just my thoughts.

 

[Wallowgreen]

A bit more information would be nice mate. For example, when you say she won't start, do you mean the engine is not even turning over or it is turning over and won't fire? As many details/observations on what she is/isn't doing as you can.

 

[GregM.]

A bit more information would be nice mate. For example, when you say she won't start, do you mean the engine is not even turning over or it is turning over and won't fire? As many details/observations on what she is/isn't doing as you can.

Thanks for the replies!

And yes, right... I mean that my 850 is turning over but won't fire.

That's why I was guessing "carbs?" in my title.

Could it be a short somewhere, if it's turning over but won't fire?

Thanks for all ideas, Greg

 

[bwringer]

Cleaning connections is an excellent idea -- you may be having a problem with low voltage at the coils. What kind of voltage are you getting at the coils? Is the bike charging OK? How's yer battery?

Also, how much choke does the bike normally need when cold? Are your air screws set correctly? Are you using too much choke when the bike is warm?

 

[rustybronco]

I would love to hear as much info as possible as to all the different things that could be wrong.

Could be wrong?

cranking speed to low.
low/no voltage at the coil(s)
bad connection(s)
flaky kill switch
bad coil(s)
bad plug wire(s)
fouled plug(s)
bad spark plug caps
spark plug gap to large
no or intermittent signal from the signal generator
bad ignitor
carb passages blocked
choke cable not actuating the choke linkage
petcock issues
crud in fuel tank
valve clearance(s)to little
blocked air filter

or something else I might be forgetting...

does it crank at a normal speed when this no start issue occurs?

does it have good spark across all four plug gaps when you are having the no start issue?

does the engine seem to run abnormally hot?

does putting it the petcock on prime change anything?

(sorry Brian, I was putting this together while you had posted your response)

 

[GregM.]

Thanks, you "super veterans"... I remember enjoying all your great advice over the years (we had emails 3-4 years ago).

I'm starting with a new battery this morning... and then, going to a mechanic this afternoon (I think).

Always love to hear any other tips/suggestions/ideas... I will take this info... figure it out (with the mechanic)... and I'll follow up here later with what else I learn!

Thanks so much for your time and info

 

[dpep]

Does the bike just turn over very slow like the battery is almost gone? If so your problem is electrical. When the engine is hotter the resistance to current flow is increased which is why you only experience it after the bike has been running for a while. Battery/RR/Stator/Connections--mix and match.

It is an experience I had many times with my 1980 850G before discovering this website ten years ago.

P.S. Whether or not the new battery seems to solve your problem, be sure to clean those connections as recommended and to test the system via the Stator Papers located on the GSR homepage. You did not say how old the current battery is and given the long periods it sat idle over its life it is possible that is your only probem. But if it is not and there is some underlying issue that drained it, there will only be a short while before you have to replace it again.

 

[GregM.]

Does the bike just turn over very slow like the battery is almost gone? If so your problem is electrical. When the engine is hotter the resistance to current flow is increased which is why you only experience it after the bike has been running for a while. ""Great info THANKS I love this site!! "" Battery/RR/Stator/Connections--mix and match.

It is an experience I had many times with my 1980 850G before discovering this website ten years ago.

P.S. Whether or not the new battery seems to solve your problem, be sure to clean those connections as recommended and to test the system via the Stator Papers located on the GSR homepage. You did not say how old the current battery is and given the long periods it sat idle over its life it is possible that is your only probem. But if it is not and there is some underlying issue that drained it, there will only be a short while before you have to replace it again.

The battery is approx 5 years old... I put a new one in about the time I got the bike. (Probably due to advice I got at this site.) And... I think that my "maintenance rides" 3 times a month, approx 40 minutes on the freeway for each one, over all these years... has kept the battery in decent shape. For example... It started the bike 2 months ago in Dec while we were having consistent 30 to 40 degree weather.

Anyway... IT IS approx 5 years old... so, I think it's probably time for a new one.

And it would be AWESOME, if THAT is the only issue with this starting problem

 

[BassCliff]

Hi,

Has anyone mentioned a valve adjustment? When was the last time you checked the valve clearances? It might not be the root of your problem, but could aggravate it.


Thank you for your indulgence,

BassCliff

 

[GregM.]

Hi,

Has anyone mentioned a valve adjustment? When was the last time you checked the valve clearances? It might not be the root of your problem, but could aggravate it.


Thank you for your indulgence,

BassCliff

Right On!!
Again you guys are awesome!
And yes, "rustybronco" mentioned Valve clearance in his list.

I don't know mechanics enough to know why "too tight a valve clearance" could cause difficult starting to an already warm bike... But I believe you
Thanks

 

[exbellicus]

Right On!!
Again you guys are awesome!
And yes, "rustybronco" mentioned Valve clearance in his list.

I don't know mechanics enough to know why "too tight a valve clearance" could cause difficult starting to an already warm bike... But I believe you
Thanks

This was posted by Steve in another thread.

"The valves control how much air is admitted into the cylinders and when. If the clearance between the cam (the bumpy stick that opens the valves) and the valve/shim/bucket assembly is not correct, the efficiency of the engine can be greatly reduced. If the clearance is neglected long enough to be reduced to zero, the valves can actually be damaged because they are not closing long enough to transfer heat to the cylinder head. This procedure is important enough that Suzuki recommends that it be done every 4,000 miles."

 

[GregM.]

Thanks "exbellicus" for the excellent tutorial
THAT makes sense... and I understand it a bit better now. I will make sure the valves get checked soon... and many of the other tips as well.

UPDATE - Thanks a ton for the awesome help so quick! I think that I have enough info now. I put in a new battery today, and it already seems better... however it rained most of the day... so I didn't get to really repeat past situations. But with everybody's help, I feel better about getting this completely sorted out. I will post back here later with whatever the final issue really was
I appreciate it... Greg

 

[Guest]

I remember you :-\\\

 

[GregM.]

Final Update –
The new battery solved it. Thanks for the education I always figured that if the battery was strong enough to start the bike in cool (around 40 degrees) weather… that it was in pretty good shape !

I did not know that when the bike is all warmed up, there is additional resistance in the electrical system (basically the coils ?) and that this requires even MORE juice from the battery to start the engine.

A few of you mentioned this possibility – and THANKS, you were right on !
I realize ALL the other advice is important too… and would like to make sure that it’s up to par as well.

THANKS for the quick and very helpful info.

 

[tkent02]

The new battery solved it.

Doubtful. The new battery hid the problem is more likely.
Your problems will return unless the electrical connections in the charging system are cleaned.

 

[Big T]

Greg

While I recommend you review the Stator Papers, some basic parts of it come to mind:

1. Uncover your battery, start your bike and use a VOM to see what your voltage at the battery terminals is at idle and at about 3500rpm. Report on that
2. Check the wires coming from the stator (left rear top of motor). follow them up to connectors to wiring harness. Pull apart and clean. If they look burnt, trim them back and replace the connectors, or just solder them together
3. Run a ground wire from the R/R (that finned thing) body directly to the negative terminal of the battery
4. Check your voltages at the battery again

 

[BassCliff]

Hi,

I agree. To be sure your new battery is going to continue to work properly, follow these links...

The Stator Papers

More On The Stator Papers


Thank you for your indulgence,

BassCliff

 

[SqDancerLynn1]

No amount of tuning can make the bike run properly if the valves are out of adjustment... #1 thing to do...

 

[GregM.]

Greg

While I recommend you review the Stator Papers, some basic parts of it come to mind:

1. Uncover your battery, start your bike and use a VOM to see what your voltage at the battery terminals is at idle and at about 3500rpm. Report on that
2. Check the wires coming from the stator (left rear top of motor). follow them up to connectors to wiring harness. Pull apart and clean. If they look burnt, trim them back and replace the connectors, or just solder them together
3. Run a ground wire from the R/R (that finned thing) body directly to the negative terminal of the battery
4. Check your voltages at the battery again

Hey Big T,

It's been a few years, glad to see you're still here (I've been off however)... Are you still getting up here for the Seattle M/C Show each Nov?
AND, thanks for your good advice. I'm selling my 850G to a friend of mine (who's also a neighbor) but I may still be here once in a while, and I hope he will get on here too. This site... and you guys... make owning one of these classic and great motorcylces, a much greater experience!!

And thanks Lynn and Cliff and Kent... I know this is valuable advice... and I hope that he and I will work on these things... since we live in the same area, it should be easy.