Chasing mysterious running issues - it's the simple things that drive you mad...

[Wingsconsin]

I have had a lot of trouble with my 1983 GS850GL this year.

It would not run WELL - It would not re-start - it would not run at high RPMs
Then the problem would stop - and it would run kinda okay for a few days...
It was so bad I didn't trust it. I was unable to ride it to a GS rally in June (sad for me)

SO - I decided to start over and get it done right.
I have
-- adjusted the valves-
--new air filter
--rebuilt the carbs (even though they seemed remarkable clean inside) with all new o-rings and a strip & dip with an ultrasonic cleaner
--all holes in jets have been cleared manually with a wire of correct size.
--new boots both intake and exhaust with new orings
--installed new plugs (checked the gap 3 times)

Here's the ONLY thing I have found that may have been causing the problem --



The last time (3rd) I removed the plugs and checked the gaps the number 3 spark plug wire came apart in my hand

So I clipped it back ; and reassembled it - nice and tight now .

Carbs go back on this weekend - right now they are fully cleaned and assembled on the bench (I ran outta time last night)

I hope this is the answer...

[JTGS850GL]

Think of it this way. You're now ahead of the game on doing your regular maintenance.

[Steve]

You going to meet us in Missouri?

.

[2BRacing]

If you have not already done it, I suggest that you cut back a piece of the other 3 spark plug leads where they screw into the caps as well, even though they appear OK.

That fresh "tight fit" on a new piece of plug wire does make a difference!

[Wingsconsin]

You going to meet us in Missouri?

.

It's not running -- yet -- But even so I don't think I can make it
My new target is the BC Rally in '17

If you have not already done it, I suggest that you cut back a piece of the other 3 spark plug leads where they screw into the caps as well, even though they appear OK.

That fresh "tight fit" on a new piece of plug wire does make a difference!

That's next on my "to do" list -

[barnbiketom]

for fun too you could check the resistance of the plug caps....
if the wires are loose in them, they may have created heat, and ruined the resistors...I am amazed by how many caps are out of range, and have taken to replacing them with NEW NGKs

[Wingsconsin]

It runs !! Happy happy joy joy

Finished the carb rebuild and reinstalled -
Check ALL spark wires for tightness (only the one was bad)
Started the bike and it RAN - Then went for a shake down ride (MUCH JOY )
It runs really well right now..
I think it may a bit rich but I will tune it over the next few weeks a bit better.
I have the mixture screws out 2-3/4 turns right now (started at 3 full turns out)
Synch is close but not perfect - I really struggled getting 1&2 to match 3&4

I think I need to do the idle drop method for better rich/lean settings .. that should help

BUT the bike pulls strong all the way up to red-line !

I need to ride it and de-kink it now ...

(If only the carb fairy would visit and fine tune my mixtures )

[850GT_Rider]

congrats!!

[Steve]

(If only the carb fairy would visit and fine tune my mixtures )

The carb fairy's ride is currently puking oil. Diagnosis is in process to enable a ride to Missouri.

.

[dorkburger]

A couple years ago after discovering varying plug colors, I ended up checking the coils and wires. I tested them per the manual, and one coil secondary side tested as being bad as measured from plug cap to plug cap. I went further and checked the caps and wires individually and found corrosion on all connections, and one bad cap resistor.

[Wingsconsin]

Now only confusion and some sadness...


I am about to give up on this thing...

Yesterday it ran pretty well -- so today (after I posted my joyfullness) I decided to ride the bike to work as the weather is great.

Started right up -- idled on choke for about 2-3 minutes and then away I went.
It ran so poor I don't know what to think... I changed NOTHING since yesterday afternoons ride.
Today -- it was running like on 3 cylinders - killing on me at stop lights - and had little power.

WHAT THE HECK !?!?!?!?

Anyone want a pretty good bike that needs a little understanding ....

[Wingsconsin]

The carb fairy's ride is currently puking oil. Diagnosis is in process to enable a ride to Missouri.

.

My goal is to get this bike running well enough to make next years Brown County Rally on it.... seems like an impossibility somedays...

[dorkburger]

Idled on choke for 3 minutes seems awfully long. Air leaks?

[Wingsconsin]

Idled on choke for 3 minutes seems awfully long. Air leaks?

Maybe not that long -- And it was idling at about 2000 RPM (barely on the enricher circuit)
It was as long as it takes to make into the garage, slip on my jacket and close the garage door...Maybe 2 minutes tops..
As for air leaks -- I redid the airbox Sunday before reinstalling the carbs, NEW airbox boots, ..I can't imagine how or where ...

[Sandy]

Well, at least you know what it's not. LOL. That's a start. Some ideas. Could be heat soak on some of the electronics as in ignition box, pickups or coils. For diagnostics purposes try running with the ignition cover off, swap coils and use a can of compressed air on the ignition box to cool it when the problem shows it's ugly head. The obvious, not likely but easy to check. Check for a chafed wire somewhere, bad connectors or poor fuel supply. Good luck.