'80 GS550L start troubles

[elwaxoro]

1980 GS550L.

Long post alert! I'm typing and I can't stop!

Up front you should know this is my first bike ever. Assume I don't know anything about anything. It ran on Tuesday when I picked it up. It ran Tuesday evening when I took it downtown. Every time starting on the first attempt. I stalled it at an uphill stop and couldn't get it going again with the electric start. I was successful with a roll start, however. After dinner, would not start. Took about 6 or 7 attempts to get a roll start (hooray for a pack of friends to pull me back up the hill each time!). Yesterday morning it also would not start (garaged overnight).

Last night I spent about 30 minutes with it, but ran short on time. Hopefully tonight I'll be able to spend a few hours on it.

Has a fresh, full tank of gas! It was nearly empty when I picked it up, so the first stop was the gas station.

Starter: runs strong. First attempt seemed to catch for a second, but nothing after that has even come close. Seems to turn over easily. I tried with choke on full and choke off w/ throttle. Thought I could smell gas when starting, but maybe I was catching a whiff of something else in the garage.

All fuel supply stuff looks a little sketchy. Fuel lines have an amber color. Fuel valve is a little scary looking too (see photos from sig). A clog seems likely somewhere.

Fuel valve: I noticed this was set to Prime? (vertical) which means I'd been driving it around like that all day Tuesday. Switched it over to horizontal (run?). Didn't magically cause the bike to run .

Plugs: These were totally blackened. The one I remembered to feel was not wet. There was spark on all 4. I cleaned them a bit and put them back.

That's as far as I've gotten. Tonight I will try to verify fuel flow to the carbs, and check the intake. It needs new plugs for sure, but is that something I should worry about at this point? I also have some starter fluid, is it ok to try with that (how does this work with a bike: just spray in behind air filter)?

Where should I start tonight?

Thanks for taking a look! I can't wait to get this back out on the road!

[BassCliff]

A little TLC

Hi Mr. elwaxoro,

There is a list of things that need to be addressed when newly acquiring a GS bike with unknown history. With the symptoms you describe I would suggest starting with the basics. Check the charging system and the fuel/air intake system. Details are in your mega-welcome post in the GS Owners section.

Clean all electrical connections, start with a known good fully-charged battery and go through the Stator Papers. There is a carb rebuild series available (for CV and VM). Intake boots and O-rings are usually required as well as anything else necessary to seal the intake system (airbox, etc). Adjust the valves before you balance the carbs. Try new plugs and plug caps, new air filter, new oil change and filter, flush and replace the brake fluid, etc. You've got a diamond in the rough. A little TLC will make it shine. Keep us informed.

Thank you for your indulgence,

BassCliff

[Nessism]

Hate to say it but there are a lot of unknowns when you purchase a 28 year old motorcycle. As BassCliff said, the basics are a good place to start.

Things like getting the carbs fully sorted with fresh o-rings (cycleorings.com) and the valves adjusted are a MUST. That open exhaust is not helping either since the mixture is going to be lean. Check spark using new plugs and verify the charging system is charging. Lastly, check that petcock to see if it’s flowing properly. If you’re not sure how to check, let us know.

Good luck.

[elwaxoro]

Update: Tonight I hopped on it, went for the starter w/ throttle full open: VROOM! \\/ Let it idle for 10 minutes or so, shut it down, and it fired right up with no throttle just a few minutes ago. So whatever is causing me grief may be intermittent. Something sticking open/closed somewhere...

At any rate, just wanted to share since it was pretty exciting :-D

Also: bonus newbie question! How do I get the bike onto the center stand by myself? I tried a few things, but I suspect there is a technique to it.

[SqDancerLynn1]

General Cold start procedure. Turn fuel valve to prime for few seconds, turn back to On position. Full Choke & NO throttle. hit the start button

[elwaxoro]

General Cold start proceedure. Turn fuel valve to prime for few seconds, turn back to On position. Full Choke & NO throdle. hit the start button

How does this work when the valve is "automatic?" I can switch to prime, but I have to use a thin-blade screwdriver. I also think my choke my be sticking or something.. it only comes out an 1/8" tops.

[BassCliff]

Hi Mr. elwaxoro,

Oh no, one of those petcocks. It might be best if you replace it with a new one. It's not really "automatic" but it is vacuum operated.

As for getting it on the center stand, it's more about pushing down with your foot than lifting with your arms. Make sure you have both legs of the stand touching, then push down hard with your foot as you lift gently with your arms. Granted, you have to do both, but it's more about pushing down than lifting up.


Thank you for your indulgence,

BassCliff

[elwaxoro]

Update!

Bike is starting better now that the choke cable isn't hooked around anything. I've got some cable lube for it too, but I can't get the gas tank off...

I'm not sure how this attaches normally at the back, but mine feels like there was a welded nut that broke off- it's pretty thin and I can't seem to squeeze anything back there to hold it still. Also, the bolt is too long, so the tank isn't even very secure :shock:. Looks like it'll be dremel time for me tonight, unless someone knows a clever trick.