It started losing power rapidly, then died

[slsimmer]

So I bought a '80 GS850L this year and I really like it. It's treated me well until today. So here's the rundown. After it sat for a week and a half, I tried to start it, and it wouldn't start. Cranked it for a while with the choke all the way out and it fired up. It ran rough and some of the cylnders were hit and miss for a while, but after it warmed up it came into it's own. Took it for a little ride and it gave me no trouble. Today I go to ride it to work. It starts right away, but it runs about like it did when I started it the last time. After a minute or two it straightened out. so I get on my way, and after about three miles of freeway, it starts to lose power, at first it loses power, picks back up, loses again, and back and forth a few more times. Then it starts to really lose power, giving it more throttle just makes it bog even worse. So I get to the shoulder, and as soon as I let go of the throttle the engine dies. No amount of cranking brings it back to life. So I push it for about a half mile, and try again. With the choke all the way out it runs for a second, but it misses quite a bit. After this, it won't start for a while again, then after another half mile, it does the same thing. It goes on in this fashion until I stop pushing it.
I think it is fuel, possibly the vacuum valve on the tank.
Does anyone have any reccomendations? One guy I work with says that he thinks the engine is blown, I really don't want that to be the case. Any pointers would be great. Thanks

[DanTheMan]

check your vacuum tube to #2 carb....

Check your vacuum line from the 2 position automatic petcock to #2 carb. It probably came loose. Mine has done that, if not all the way off, it's partially off, cracked, or you need a new petcock.

[Charlie G]

slsimmer,

Just about the same simptoms occured to me on my 450 on various rides and it turned out to be a petcock being bad. A new one was about $70.00 and easy for this carpenter to replace. The petcock is vacume opperated and gas won't flow if there is no vacum. Check the line from the petcock to one of the carbs for cracks or failure. In my case a aluminum plate within the petcock had cracked into five pieces and I guess was causing the diaphram to mallfunction. Blown engine???? I don't think so.

cg

[twiggy2cents]

if it is not the petcock, holding the throttle wide open while cranking will clear a flooded engine due to lack of vacuum to pull fuel into it

[Dave8338]

Check the fuel cap. Sounds very similar to a plugged vent.

[rustybronco]

my vote? petcock issues... when it starts doing it again, flip 'er on prime, or take a screw driver and loosen the fuel bowl drain screw(s) to check for fuel in the bowl(s).
it also could be ignition system giving you troubles, so take a spare spark plug with you, stick it in a plug wire and check for spark.

One guy I work with says that he thinks the engine is blown, I really don't want that to be the case. Any pointers would be great. Thanks

pointers? yes... don't listen to him, it's not blown. "I GUARANTEE IT".

[BassCliff]

Greetings and Salutations!!

Hi Mr. slsimmer,

What's the history of the bike? There are a combination of conditions that must be met for proper operation. In addition to the other thoughts already given, from what you've reported I think a carb cleaning, valve clearance adjustment, and carb sync may be in order. There's more info in my "mega-welcome". Enjoy!

Now, how about a magical, mystical, mythical, consciousness-expanding, spiritually uplifting welcome? OK!

Here is your official "mega-welcome". Please take notice of the "Top 10 Common Issues", the Carb Rebuild Series, and the Stator Papers. Now let me roll out the welcome mat for you...

Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[slsimmer]

Back to life

Okay, so I got it towed home. In the process of it being loaded onto the truck, he dropped it and broke the brake handle and points cap. Needless to say, the towing company is buying me some Suzuki genuine parts. I started taking it apart, and low and behold, the vacuum line had split at the petcock! I guess I learned my lesson because when I bought it, I looked at the fuel line and though it was a bit shoddy (copper wire twisted tight around a hose as a replacement for a hose clamp) but I rode it a couple times and really enjoyed it and subsequently forgot about it. If I had replaced the fuel line right away, I would have replaced the vacuum line also and never had this problem. Oh well. So, I took it apart and replaced the fuel line, filter, (with proper hose clamps), and the vacuum line. Being as I had to take the air box off to access the fuel line, I found out that all of the rubber boots that connect the carbs to the box had pulled free of the box, therefore not sealing correctly. So, I put it all back together correctly, and it runs better than it did before! Now as soon as my brake handle gets here I can ride again. Lousy towing company. I had really hoped that he scratched the tank too so I could get the other scratch in the paint fixed for free.

[slsimmer]

and a picture

I haven't got the hang of putting a picture in a post, so this link gets you there.

http://sethnsteph.myphotoalbum.com/view_photo.php?set_albumName=album08&id=hpim0565

[russr33]

Check the fuel cap. Sounds very similar to a plugged vent.

I agree, although it definitely sounds like you had other issues as well. On the freeway, and suddenly lost throttle response then die? Two of my bikes that had sat up before I bought them had same issue and both were fuel cap plugged vents. Pull your cap apart and give it a good cleaning just to be sure.

[Big T]

I haven't got the hang of putting a picture in a post, so this link gets you there.
http://sethnsteph.myphotoalbum.com/v...08&id=hpim0565

Go down to the lower right "Embed the photo" and cut and paste from there

[pntrdave]

couldn't he have switched the petcock to prime and ran it on home??? My bike had the same symptoms that's when I realized I was out of gas. I went to switch it over to reserve and to my shock I realized that I had switched it to reserve a few days before. Luckily I was just down the street from a station.

[Dogma]

couldn't he have switched the petcock to prime and ran it on home??? My bike had the same symptoms that's when I realized I was out of gas. I went to switch it over to reserve and to my shock I realized that I had switched it to reserve a few days before. Luckily I was just down the street from a station.

That petcock won't even prime with out a vacuum on it from turning over a few times.