Newbie question -- throttle stuck open?

[JShapiro]

If you watch the choke rail on top of the carbs when you actuate the lever, you should see it slide the chokes in and out of the carbs. It says ON and OFF on the top but there is some variability to it. You should be able to push the rail with your finger to get a feel for how much spring is there.

How long to leave the choke on is entirely dependent on temperature, humidity, etc... I generally turn mine down or off when the revs start to climb, but I'm a bad GS owner and haven't done my valve adjust yet so that could be part of it.

I just checked and although it's designed to be either on or off, you're right, there does seem to be some adjustability -- good to know.

So just to be clear, you're saying I should leave the choke on until the engine revs up like it did this afternoon, then turn it down or off?

[tthayer]

Right. The choke is just to get the bike warmed up. If it won't run without the choke then you have other issues (air leaks). Have you replaced your air filter yet?

[JShapiro]

Right. The choke is just to get the bike warmed up. If it won't run without the choke then you have other issues (air leaks). Have you replaced your air filter yet?

I haven't changed it -- I don't know when it was last replaced.

It runs fine w/out the choke, but is very prone to conking out at stop signs so I've been keeping the choke on in an effort to keep it from dying.

[Steve]

. I've been leaving the choke on for a good while after starting the bike up since it has a really hard time not dying when I come to a stop. Could this have something to do with it?

So just to be clear, you're saying I should leave the choke on until the engine revs up like it did this afternoon, then turn it down or off?

Sounds like it's past time for a GOOD carb cleaning and re-o-ringing.

When the carbs are properly adjusted (along with the valves), you should not need the "choke" for more than 30-60 seconds, then you can pull away. By the time you get into second gear, you should be able to turn it completely OFF.

.

[pete]

Mate I'm gonna pop in and say welcome to the forums, but not a lot I can add to the already excellent advice on the posts here

It does sounds suspiciously like either a hanging idle problem (unsealed air intake somewhere), excess choke, idle set to low (conking out), and/or an old throttle cable that needs lube.

[JShapiro]

Just got back from a mechanic who is reputed to be a whiz w/old carbureted motorcycles. He confirmed what some forum members had guessed, the carbs are not properly cleaned, and made some adjustments that really helped (slow speed fuel screws on both carbs, and idle speed). It doesn't cut out at stop signs anymore and the revving issue has not returned.

He also sold me some fuel additive called startron that he said could help. His advice was to ride it for a few hundred miles w/the additive and see how it's doing before taking the next step.

[tkent02]

I bought the bike from a mechanic and he said that very recently (i.e. this year) he'd cleaned and sync'ed the carbs and checked valve clearance and found it to be good. In fact, he did a lot of work to it and told me all maintenance was up to date..

Just got back from a mechanic who is reputed to be a whiz w/old carbureted motorcycles.

You really need to get away from this "mechanic" idea. The ONLY person who will put in the time and effort it takes to keep your old motorcycle safe is you.
Learn to do it yourself, or get a new bike.

[Agemax]

You really need to get away from this "mechanic" idea. The ONLY person who will put in the time and effort it takes to keep your old motorcycle safe is you.
Learn to do it yourself, or get a new bike.

more helpfull advice

[Nessism]

You really need to get away from this "mechanic" idea. The ONLY person who will put in the time and effort it takes to keep your old motorcycle safe is you.
Learn to do it yourself, or get a new bike.

I agree with Tom. 30 year old bikes need maintenance all the time, and if you go run off to a mechanic for everything, at $75+/hour, you are going to go broke. Most guys I know that don't do their own maintenance neglect the crap out of their bikes and only fix stuff that breaks. People like this should just get a more modern bike that doesn't need as much work.

[Agemax]

I agree with Tom. 30 year old bikes need maintenance all the time, and if you go run off to a mechanic for everything, at $75+/hour, you are going to go broke. Most guys I know that don't do their own maintenance neglect the crap out of their bikes and only fix stuff that breaks. People like this should just get a more modern bike that doesn't need as much work.

maybe so but some people dont know a spanner from a hammer, sure they can tinker but they may end up doing more harm than good,
if they bought a new bike and it packed up, or had a problem, which they do, he would stlii have to take it to a mechanic to look at it

[cowboyup3371]

True but at least that new bike would probably be covered under a warranty so the cost wouldn't be as high. I also agree with Tom mostly because a mechanic tried to screw me out of money on my bike. My truck is a different story only because I can't but with the bike, yea, I'll find a way to do the work myself. If I screw it up at least I have no one else to blame.

[Agemax]

True but at least that new bike would probably be covered under a warranty so the cost wouldn't be as high. I also agree with Tom mostly because a mechanic tried to screw me out of money on my bike. My truck is a different story only because I can't but with the bike, yea, I'll find a way to do the work myself. If I screw it up at least I have no one else to blame.

fair comment but maybe he should try and find a decent, fair priced mechanic that he can trust, or a good mate

[hampshirehog]

The guy who told you to try starton ( I presume it's akin to our Redex) sounds ok. He could have ripped you off or he could have done a proper strip and clean of your carbs which would not have been cheap (it takes time, knowledge and care to get it right).

If you try running it with a fuel additive and it starts to run fine you might be home and dry. If it still doesn't run properly you can always strip the carbs anyway and all you've lost is a few quid on the additive.