Getting closer - non-running 1982 GS850GL

[Guest]

Hi,

Trying to bring back to life a 1982 GS850GL.

On the running side here's what's been done;

clean carbs and replace orings
replace intake orings
new air filter (OEM airbox)
new plugs and caps
new battery

The bike is very hard to start - needs choke until it gets warm.

After warming it idle's high and bogs down when giving gas (throttle). Plugs #1 and #3 look ok. Plugs #2 & #4 look lean.

Suspect I need to check the condition of the coils.

What else should I be looking at?

Your knowledge is appreciated.

Thank you

[jsandidge]

Checking and adjusting valve clearances is a must. Hard starting is an indication they are too tight.

[Steve]

How did you "clean" the carbs?

Did not see a mention of carb sync.

Drew is right, valve adjustment is MANDATORY.

Some "choke" when cold is absolutely normal, but should be able to turn it off in less than a minute.

Proper starting technique is also important. If you are using the throttle at all while starting, STOP IT.

.

[mauricedonini]

Hi

Good points.

1. Did adjust the valves.
2. Did not sync the carbs. Will look into that.
3. Not using throttle when starting.
4. Carb clean. Did take the carbs apart, clear the orifices clean the bowls, etc following along the Ed Ness rebuild document. Did not do a carb soak.
5. Did spray WD40 on all the rubber parts connecting the airbox to the carbs to the engine. No noticeable leaks.
6. Did inspect the intake boots - no noticeable cracks.
7. Pilot screw turned out 2 1/2 turns on each carb.

Inside the carbs looks original, with no damage.

Can a TwinMax be used to sync the carbs? Sync 1 to 2, then 1 to 3 then 1 to 4.

Thanks for the advice.

[Steve]

1. Did adjust the valves.
Good
2. Did not sync the carbs. Will look into that.
Really needs to be done
3. Not using throttle when starting.
Good
4. Carb clean. Did take the carbs apart, clear the orifices clean the bowls, etc following along the Ed Ness rebuild document. Did not do a carb soak.
Congratulations on a good start, now you have a great opportunity to do it over and do it right.
5. Did spray WD40 on all the rubber parts connecting the airbox to the carbs to the engine. No noticeable leaks.
Have never seen decent results by spraying anything to look for leaks. Not sure that WD-40 would be the spray of choice.
6. Did inspect the intake boots - no noticeable cracks.
It's not only cracks you are looking for, it's hardness and shrinkage.
7. Pilot screw turned out 2 1/2 turns on each carb.
Might be close to where you will end up, but if one (or more) of them needs 2 3/4, it will run rough enough to make diagnosis difficult. I start with 3 turns out to provide a rich mixture, then slowly turn them in, listening for best mixture.

Inside the carbs looks original, with no damage.

Can a TwinMax be used to sync the carbs? Sync 1 to 2, then 1 to 3 then 1 to 4.
Forget the TwinMax. Some have claimed they can do it, but once you see how changing one adjustment affects all the others, you will be glad that you got a tool that can view all four at the same time.
The current favorite is the Morgan Carbtune. click link.

Thanks for the advice.
You are welcome.

.

[mauricedonini]

Hi Steve

how does hardness / shrinkage of the intake boots affect performance?

Thank you

Maurice

[chuck hahn]

They get so hard the clamps cant squeeze them tight to the carbs...thus an air leak. Shrinkage starts sepperation of the rubber off the flanges and makes cracks...thus air leakage.

[mauricedonini]

Hi Chuck

Thanks for the info. The are hard. Going to try the wintergreen oil/alcohol trick to see if that helps.

[mauricedonini]

Hi,

Here's an update.

After sitting for 12 hours, the bike started right up. For now, this eliminates the valve adjustment as an issue.

Tested the coils. Right side (plugs 1&4) - 22K. Left side (plugs 2&3) - 11.6K. Uh oh. Looks like the left coil is bad.

Also found gas leaking out near the airbox. Looks like the petcock needs to be rebuilt/replaced.

Also am hunting down a Carbtune.

Thanks for the help.

[chuck hahn]

Just cuz it started right off does NOT eliminate the valve adjustment by any stretch. Gas coming out the airbox is more likely to be a stuck float, wrong float hts than a petcock issue. However to check the petcock do the following.

Get 2 clear soda bottles that are clean and dry inside. Get two lengths of hose..1 for the vacuum line nipple and 1 for the fuel line nipple. put a line from each nipple into its own bottle and have the tank full....for the maximum fuel weight the tank will ever be at.

Let it set overnight and inspect both bottles. If the petcock is leaking past the on/off oring youll find gas in the bottle with the fuel line in it. If its leaking back past the vacuum diaphram youll find gas in the vacuum line bottle. Simple and easy test or a petcock.

[Steve]

Tested the coils. Right side (plugs 1&4) - 22K. Left side (plugs 2&3) - 11.6K. Uh oh. Looks like the left coil is bad.

Before you go condemning your coil, check the spark plug caps. Check all four. The coil itself should have about 20k ohms, each cap should have about 5k ohms, for a total of about 30k ohms. It's unusual to be low, but check them, anyway.

Also am hunting down a Carbtune.

It's not hard to hunt one down.

Go back to post #5, click on the link I gave you.

.

[mauricedonini]

Hi

Wanted to send an update on this thread.

Replaced the intake boots. This helped, but did not resolve the issue.

Broke down and did the carb soak. This was the key.

Bike is now running very good.

Appreciate all the help.

Thank you.