"Choke" issues

I know the choke on these bikes arent really chokes, but I am having trouble with my engine when it is not choked. If I start the bike with the system open, it runs and idles fine for a bit then idles at anywhere between 2 and 4k. As I move the 'choke' lever in, the RPM's come down, but too far and the bike dies. If I leave the lever where the bike idles well (about half way), then the RPM's are very slow to come down after rev. Any ideas what may be causing this?

 

It could be as simple as the idle screw needs adjusting, you will find it between the 2 centre carbs near the bottom, its about 1cm across

 

how long have you had the bike? When were the carbs cleaned last? do what acergremlin said...

 

Ive been wanting to play with that screw for a while now, but cant find it. Do I need to remove any parts to get to it?

Ive only had the bike for a few weeks. I was told that the carbs were cleaned in Jan of this year, but looking through the service reciepts that I got with the bike, I can only find one for a carb rebuild. I would follow the steps that people have posted here and clean them myself, but I am really afraid of what will happen once I try to take them off. This is my first bike and as such I have never worked on one. I dont have tools really either. I guess Im a bad bike owner.

 

Could also be an air leak. Make sure all the rubber boots (from the engine to the carbs and from the carbs to the air box) are in place and snug.

 

I will try this. Thanks.

 

nothing to remove to get to the idle screw, just use a torch to have a look you cant miss it.

Have a look at this its the knob between the middle two float chambers

http://xjbikes.com/coppermine/displayim ... s=300.html

 

This is what my bike was like this spring. I had to keep the choke on about 1/4 or a little more and then mess with the idle screw. The best I could get was a good idle but the high rev coming back down slow. Tore the carbs off and cleaned. No more problem. I do however have the choke set so that it is on just a tiny little bit to compensate for a lean idle i have. My pilot screws are plugged off and I have not removed them to adjust idle the proper way. When I removed the carbs, I sprayed the carb boots with amoral and then pushed them back into the air box. I then could remove the carbs by pulling them out towards the battery side. Then clean good by following the other posts and put back in same way. Put some more amoral on the inside of the boots with your finger. This will help in sliding them back onto the carbs. Not a bad job, just time consuming. I think it took me 6 hours start to finish my first time.
Good luck

 

Most likely thing is that the little teeny weeny holes in the pilot jets are blocked. They are deep down in the tubes and very hard to get out of the mikunis. The best way i have found is to pull a wire from a wire brush and wiggle it through the hole. Once you have done this the bike will idle like its new.