Hi guys,

I've had my GS500F sitting for two years since it's last ride.

I've put in a new battery, changed oil and put in new spark plugs.
The fuel had stabilizer added to it back when it was fresh.
That stabilized fuel might be the culprit here but would like some advice.

I was finally able to get the bike to turn over. The idle is way off, but I've tinkered with that before.

The exhaust sounds a bit funny, like it's popping. As I said above, that might be the bad fuel?
I took a video, was hoping someone with more experience could give me an idea.

Is it fuel? Is it maybe the carbs need cleaned?
Does it just need rode a bit?

https://1drv.ms/v/s!AlZhdUy41wpMgZJIDUYfLugTBLlm0A

Try running it briefly with one plug connected, then the other... to make sure both cylinders are working ok...
Drain the fuel, and put in fresh and ride it some.

Thank you Sporty!

With the right spark plug disconnected, it wont turn over.


Looks like I can try swapping the plugs first.
Maybe the connections themselves next.
Might be Carb related. Going off of this thread: http://gstwins.com/gsboard/index.php?topic=70686.0
and maybe this: http://gstwins.com/gsboard/index.php/topic,68478.0.html

Ill have to try these the next time I have some time to work on it.

One thing I read on that second post was about a ground going to the bike chassis. Since I just replaced the battery, it was fresh in my mind. It mentioned a second cable coming off of the negative of the battery and to the frame of the bike, as a return kind of?

Anyone have a  photo of that? I dont think I have that. I think its just one cable going to POS on the battery, and one going to NEG on the battery.

Check spark on the dead (left) cylinder. Connect a spark pug to the lead, ground the plug to the cylinder head and crank it over.

If it has spark,  move onto compression and fuel.

Check compression if you have or can borrow a tester.

If compression is good enough move onto fuel. You'll prob find the fuel bowls dirty, crusty and carb  jets clogged.

If this was a known good running bike before storage and it has good spark, just move on to the carbs and don't worry about a compression test if you don't have access to a tester.

I took the last piece of advice, since it had previously run fine, and checked the carbs.
In the left carb, I found green gunk. Looks like stale gas, or maybe the green is the corrosion on the brass jets. I tried cleaning it off best I could but I don't think I did a good job.
The right carb looked fine, bright clean and shiny.
I cleared the bowl on the left, blew out the jets with carb cleaner (didnt check the upper) and put the carbs back on the back and everything back in its place. I had high hopes that this would fix it, but it did not.

I again tried starting with spark plug disconnected on either side, only when connected on the right did it start, same as before.

I then put a spare spark plug in the hole, on the left, and grounded it to the block, and tried starting and did see spark.

So since there is spark, I think that points me back to the Carbs. I ordered a rebuild kit and will replace the brass and anything else I can in that left carb.

Do I need to worry about the upper part of the carb? Looks like the needle and diaphragm live up there?

So I removed the carbs and cleaned them, replaced *some* of the parts with a Carb kit I ordered.

I put them back in and after a good bit of cranking the GS fired up. Wildly unstable on the RPMS.
Turned off.
Tried with just right plug connected only (previously working), and fired up just fine.
Tried with just left plug connected only (previously notworking), and fired up just fine.
That solves that issue.

However now that it is running, it is pretty rough. Any little throttle I give it causes the RPM to drop and then it dies entirely.
The few times I can give a throttle and it doesnt die, its almost a delayed reaction for the RPMs to briefly go up and then come back down.

My best guess is that something I did in the Carbs is 'sticking'. From other posts and research maybe the diaphragm needle is sticking?