Hello all. New to the forum. I did a quick search and didn’t see this addressed previously.

I have purchased a nearly immaculate ‘83 gs300. Runs and drives and looks perfect...except when it is cold. Starts instantly and idles perfectly. But takes 20 mins of warming up before it has full power. Turning the throttle when cold and it goes fine for a second or two and then it bogs down and barely runs until I let off the throttle. Then it goes back to idling perfectly. If I persevere and keep warming it up, this eventually clears up and away I go.

It is so sudden and sharp that I think it could be electrical, but how could that be? Seems to be temperature related. About to change spark plugs. But would love to hear some educated opinions before I spend $.

Cheers

 

Are you using the choke to warm it?

 

 

When it's cold, it dos need it. Once it's going slowly open the choke till it's running on it's own without it. You need to be letting it warm up anyway before you take off. On a warm normal day, let it idle about a minute. On a colder day let it idle more. Use that time to look over things. It's best to spot a low tire at home and not on the road.

 

It goes on it’s own perfectly without the choke. And warming it up is fine. I just know that I shouldn’t have to warm it up and go through cycles of shutting it off and starting it up for 1/2hr before the throttle works the rpms to be able to hit road speeds. My other bikes, and every other normally functioning bike I’ve ever seen, rev fine once it is warmed up for a minute or two.

Warming it up for a minute or two while other items are inspected is always great advice, just not the actual solution to this engine problem. 👍

 

You may need to look at cleaning the carb/carbs. If the exhaust has been modified it will need to be rejetted. If there's more than one carb they need to be balanced with a manometer. This and the above is all of the "places to start"

 

Thanks. I was figuring as much. Was hoping someone who had experienced this before would have a magic pill for this. 😂 Cheers.