non-starting GS850GLD

[normcoffey]

Hello, I recently bought a non-running 1983 GS850GLD with only 2,700 miles. Previous owner says the carbs were rebuilt a year ago, installed but the bike was only running on 3 cylinders, removed again, the offending carb cleaned out, and then the carbs were put in a box until a year later when I bought the bike.

I bought a new battery, changed the oil, oil filter, and spark plugs. I reinstalled the carbs as I figured they were rebuilt already and tried to start the engine. Basically the engine will not start. I am getting spark and the engine is spinning fast enough so it's got to be the carbs I figure. I am going to strip down and clean out the carbs myself as I'm not sure what else to do.

Also, the petcock is a problem too. Anyone have an extra one I could have or purchase? The petcock diaphram is fine and it does not leak, the problem is that the prime position does not open the valve. The little brass tab inside will not push the pin in the diaphram properly to open the valve.

One last thing, with the key in run position the sidestand light on the speedo is on with the sidestand up or down. I've had to hold the cluch lever in when I've been attempting to start the engine. Normal?

Sorry for the long post, any help would be appreciated.

Norman

[mark]

Are you sure you're getting gas to your bike? You say gas isn't flowing on "prime". Is it flowing on "run"? Usually if the bike hasn't been running for a while, I have to use prime to get enough gas into the carbs to start it.

You can pull your vacuum line (the smaller one), turn you're petcock to "run" and suck on it or use a Mighty-Vac to see if fuel is flowing when you're getting vacuum to the carbs.

I would make sure you're petcock is working correctly before you go to the carbs.

[normcoffey]

I did just that and was able to fill the fuel bowls, but no I'm not sure that gas is getting through the carbs and/or getting into the engine. After some trying, I pulled the spark plugs and they were not wet with gas. I also tried spraying starter fluid into the carbs and it still would not start.

Norman

[mark]

How's your compression?

[normcoffey]

saga con't

Well I rebuilt the carbs and fixed the petcock tonite. So the carbs aren't the problem, I think. Spraying starter fluid into the carbs has no effect on starting either.

I checked for spark again at the #1 and #4 plugs and it seems to get a few sparks when the button is first pushed then intermittent or nothing at all. After the first few seconds, of the engine spinning, it seems to act eratically / jumpy; very strange.

I cleaned the coil contacts and measured the resistance on each coil at 4 ohms, so they seem OK.

Could be igniter or cdi? How does on check these? Any help please!

Norman

[normcoffey]

Jumpered with the car battery tonite. Improved spark, but still no start! Prior to that though, the starter button was doing nothing when pressed as well as when the key was on run, tail light and sidestand light were not on. After two hours of tracing wires; behind the head light, a diode in a plastic sleave was burnt looking. I removed the diode and connected the wire on either end together without it, and viola, everything works again. I guess I should replace the diode as I'm not sure what it does. Back to the still kinda weak spark, I guess I'm looking at new coils/wires?

Mark, compression should be fine as the engine only has 2,700 miles on it.

Norman

[Steve]

To answer the two parts of your question that have not yet been addressed:

1: sidestand light...light should be off when the stand is raised, but it might not go off until the engine is running.

2: clutch to start...normal, unless you go behind the headlight (again) and bypass the switch. Find the wires coming from the clutch switch and locate the connectors in the headlight housing. When you have found both connectors, separate them, connect the two on the bike to each other. You can connect the two from the switch to each other, too, but it does not matter. You have to be careful doing this though...now the bike will start while in gear on the sidestand. If you forget to check for the Neutral light, you might get a real surprise when you hit the starter.


.

[normcoffey]

A few recent developments:

1. I just read that the airbox must be on for the engine to run right. I never would have thought that would be, I've trying to start without it on.

2. I stripped and cleaned out the carbs but since the idle air mixture screws still had the plugs in them, I left them along. Well I drilled out one of them and removed the screw assembly; it was all gritty, almost looked like corrosion. I'll drill out and remove the other three, then clean screw and hole, re-assemble, install airbox and try to start it again.

BTW, the battery is new.

Thanks,
Norman

[flyingace]

Being a '79, I'm assuming a points/condensor ign system.

Your erratic spark sounds like either the condensors are bad or the points aren't opening enough. I would check my point gap to make sure it's adequate. If it's OK, then try new condensors.

[normcoffey]

Flyingace, actually is a 1983 GS850GL model.

[Steve]

For a quick test, the airbox does not have to be installed.

Hang a shop rag over the input throats of the carbs, and use tie-wraps or tape around the outer carbs to hold the rag there. It provides just enough restriction to simulate the airbox. While it will allow you to start the bike and rev it up to check it out, it will not be accurate enough to do the fine tuning of the mixture screws. Since you are just trying to start it now, go for the quick and easy until it at least runs. Once you get it running well enough, you can take the time to install the airbox (once), then do the fine tuning.


.