New problem with the bike

[1978gs550E]

so last night I'm out riding. I have mentioned before that I think there is a problem with the carbs on my bike because when I start it, it has to be on half choke at 4K rpm for a long time before it will run properly. Well when I started it up last night, I only had to stay on half choke for about 5 minutes and the rpms dropped to 2K after about 2-3 minues (never happened before). After that, I turned the choke off after another couple minutes and it was staying steady at 2K.

I decided to take it out with a buddy of mine since it was running so well. We rode around for about 20-30 minutes and I noticed it seemed to be handling well. I was getting quite a bit of response out of the throttle which was also new. Towards the end of the run I then started to notice that the bike seemed to be starved of power coming off of stops. I'm at a light just about to get home and the thing dies on me. I pull off to the side of the rode and try everything to get it to started but it won't. The lights were really dim so I thought maybe the battery was going or something.

I left the bike and came back with a trailer. I wanted to try and start it to see what would happen. It started right up, idled fine after about 5-10 minutes but as soon as I put it in gear to try and ride it home, dead again. WTF?

Some background info is it's a 78 GS550E that's been beat on. It use to run fine before I got it. I've had battery problems with it before. Also, I think the petcock might be broken because the PO told me to turn it on PRI when I run it so it gets enough gas (I'm thinking that could be the problem but I want to make sure). I also think that whatever the part is on the bike that charges the battery when I'm riding might be broke.

Any help? Sorry for the long post but I thought it was all relevant.

[buster]

Definatly start by either rebuilding or replacing the petcock. You should not be running on PRI.

Also its the Stator that would be your charging issues you can check the Stator papers to find out more on how to check that out.

Your "starved for power" might have just been your lack of spark, but someone with more knowledge can chime it about that.

[Nessism]

Sounds like you have a 30 year old bike that needs some maintenance. Basic routine with something that old is to rebuild the carbs and replace o-rings, replace o-rings on intake boots, adjust the valves, and based on what you say about the petcock, replace that as well. Oh, and don’t forget to clean the air filter, clean/replace the points, replace the spark plugs, and check the charging system. Do all this stuff and you will have a reasonably reliable bike. If you wait to do basic maintenance, the bike will likely break down on regular intervals.

[1978gs550E]

Alright thanks a lot. I'm going to look into the stator page