New rider, hot bike + high idle

Hey, I'm a completely new rider, so I'm not sure if either of these things are COMPLETELY normal.

I have an 83 XJ750 maxim, it has about 24k on it, but it seems to have gone through some hard times.

When it first starts, it idles at about 500. After probably 10-15 minutes of riding it idles at 3000.

Not only that, but it's HOT to the touch. Like singing my ankles hot, and I thought I saw a bit of smoke.

Is this normal? What could cause this? Thanks in advance to anyone who could help. I can trade light residential and commercial electrical help.

 

There are many things that could be the cause. But from my experience (which is limited) try this.

Your Choke or fuel enrichment cable is stuck. Follow it and make sure that it's working properly.

Your idle screw, in the middle of your carburetor facing the front of you bike might need adjusting. to do this , make sure the bike is running hot and then adjust the screw little by little to bring down your idle. It should idle around 1250 rpms. Listen to what it likes, aircooled engines are all different.

Your carbs might need adjustment. Benchmarked and synced. Huge pain, need some patience, the right tools or a really nice friend to show you how. Get the manual and see what's involved. Carbs are a bitch, especially when you have four of them.

As for the smoke, check your engine and eyeball the problem. Make sure your engine is clean to see where the problem might be coming from. Make sure you have not overfilled the oil. Check your oil when its cold.

Good luck,

81 XJ650

 

tell us more info about the bike, youve done the most important part so far by coming here, the guys on here can and will help you out, me personally wouldnt let the bike idle at those rpms for too long,,its not good to cook the engine like that, normal rpms are 1100-1200.first things first, check your oil, always change oil when you buy a new bike, and i would change plugs as well, check choke and throttle cables make sure their not binded and have free movement, with those low kmhs sounds like a simple fix, patience and knowledge will get that bike runnin perfect, lol,,weve all been there, stick with it dude advice is free and check these forums often, im limited on wrenchin but im learning alot, when shes warm try backing out (counterclockwise) the main idle screw..big knob middle of carbs should be airbox side,

 

Sounds like you need to pull the carbs and give them a clean, plenty of info around on this site.

Chacals "overload hour and Church of clean" Big fitz has plenty of photo how to's which are great.

Also be prepared to pull top cover and check valves, once done the first time you will wonder what all the fuss was about!

Also safety info, date codes on tyres, and brake lines, delamination on rear shoes.

welcome and good luck

 

When you change the oil, SMELL IT. It would actually be a good idea to smell it right now. Open the filler cap and have a whiff. If it smells of gasoline, you have carb float problems and need to stop trying to ride the bike until they're fixed.

You've bought a 30-year old motorcycle. There will need to be a LOT of work done if you want to ride it safely; it's not an old car. A lot of things will need to be attended to first. This will be a DIY proposal; most shops won't touch old bikes and those that will often don't know what they're doing. The amount of work that will need to be done would run up a labor bill about 5X what the bike is worth anyway.

Read this, this is absolutely critical: http://xjbikes.com/Forums/viewtopic/t=15874.html

Then read this carefully: http://xjbikes.com/Forums/viewtopic/t=24010.html

And this: http://xjbikes.com/Forums/viewtopic/t=14581.html

And then get yourself a service manual and let's get busy.

 

My 85 xj700 idled nice when cold, but when hot it would alway rev up at stop signs or any time I grabbed the clutch.
Valve shims needed replacing! (some were pretty tight)
idles much better now