Now it wont even start!!

[Cullen]

OK here we go. I have a 1981 GS850G with just over 5,000 miles that I recently purchased. It ran perfect when I got it. However the other day on a short ride it suddenly died. I pushed it home and managed to get it started a few times, but for only a moment. Replaced the spark plugs and now it wont start at all!!! And I'm positive there the correct plugs. What now?!

[Dave8338]

Does the bike turn over with the starter? Have you checked fuel flow from the petcock? Where does the voltage read at the battery posts with the bike off / running? Are you getting spark?

[Billy Ricks]

With the age of the bike and the low mileage you can almost bet you need to clean the carbs. Look on the left menu of the site's homepage for the Carb Clean-up Series. If you follow it you should be able to straighten out the problem. You should probably check valve clearances too if you think you can handle the job. You'll get plenty of help here if you tackle the job yourself. If you do the valve adjustment yourself make sure you put a rag over the cam chain tunnel to keep from losing anything in the crankcase.

[BassCliff]

Hi Mr. Cullen,

And welcome to the GSR Forums.

If it cranks and gets spark (which it sound like it's doing) then your starter and other electrics are good. If it's not sparking then perhaps a perusal of the Stator Papers is in order. Make sure you have good grounds and clean electrical connections all over. Run a dedicated ground wire from your regulator/rectifier to your battery's ground connector. It's possible that your stator died.

The symptoms make me think fuel. On these old bikes the petcock often goes bad. Most folks here don't bother with a rebuild kit and just get a new one. To test, put the petcock on the Prime position (PRI) and see if it will keep running. But don't leave it in that position or you'll leak gas into the oil and everywhere else. Messy. Also check to make sure the tank is clear of rust particles and other debris. There's a screen at the bottom of the tank/top of the petcock that can sometimes get clogged.

Is there an inline external fuel filter on the gas tank's output? If so, take it out of the loop.

Forgive me, I'm just being thorough, after you changed the spark plugs, did you put the plug wires back on the proper plugs?

How does your air filter look? The 850's like tightly sealed airboxes. There should be no air leaks anywhere in the fuel/air pathways (carb boots, O-rings, etc). Rebuild carb info here.

Thank you for your indulgence,

BassCliff

[Billy Ricks]

A couple other things to check are the fuel tank vent up under the cap and if your bike has a vacuum type petcock you can pull the vacuum line off at the carb and suck on it to see if it holds vacuum and allows fuel to flow while the vacuum is applied. I'm still pretty sure you need to clean the carbs though. It only takes a couple of months with fuel drying up in the bowls to screw them up.

[BassCliff]

I am such a parrot!

I just wanted to say thanks to all of the good folks here who are teaching me to be my own mechanic. Just about everything I've learned about GS motorcycles I've learned here. I sometimes sound like I know what I'm talking about. :-D

Mr. Cullen, by hanging around here you will also become a good motorcycle mechanic and a better motorcycle rider.

Have you checked the valve clearances yet? But with only 5000 miles, I can't see that they'd be so tight as to not let the motor start.

Thank you for your indulgence,

BassCliff

[Cullen]

Wow you guys are amazing!! My first bike was a 1981 Honda CB750F and their forums were pretty worthless. This is such a relief. I'll be sure and keep you posted

[spyug]

Bikes are all pretty basic:

Gas
Spark

First off: how is the battery? full charge and in good shape? How are the grounds? Are you getting a spark?

Gas: A good petcock flowing juice? No juice getting to carbs= no go.

Sorry to be criptic but its one of two things really.

Eliminate things. Do you have spark? Do you have gas to carbs?

Narrow it down.

You can do it.

Let us know what you find.

Cheers,
Spyug

[MelodicMetalGod]

Cullen,

Welcome to the show! This place (which means these folks, because they ARE what make the place) is great!

The first thing you'll want to do is post as much info as you can in terms of what symptoms your bike is showing and under what conditions. The more complete and relevant info you can post relating to the issue, the better advice you'll receive.

Best of luck!