[Fastymz]

My bike was good an hot when I got home yesterday. It was 98 degrees outside and I just ran it hard. So I had just enough time to sync carbs. They were off but not that far, and I also adjusted them at 3000 rpms too. I took it for a short test run. It seem to help with the rpms rising but they still hang for a monument after throttle is released and it idles about 400-800 rpm after ran above 3000 rpm when hot. I did get the idle down to 600 and it ran not great but stayed running. I set the idle at 1000 now. I'll see what happens once I get it out for a longer ride.

 

[Fastymz]

Update, I removed all 4 slides they all looked good couldn't find any damager to rubber, needles or slides. inside of carbs where slides go looked very clean. I still have the issue when its hot the idle increases from 1100 to 1800 when hot outside and bike is warmed up. RPMs hold at 2500 or more when throttle is released some times for seconds and other times for a lot longer. Now when the outside temp is below 65 and the bike is cold this never happens. Also re synced carbs helped a lot but I still have this issue? Also when the rpms are racing adding choke make then go higher. its the worse when I go to restart after riding and getting it nice and warm and the outside is above 65. Its hard to restart takes a lot of cranks and idle races very high once it starts some times around 3500rpm and other times about 2000 plus. Other wise the bike seems to running good. What else should I do or try.
When the idle is racing the idle screw is seated and it has no affect on lower rpm. The only thing that helps is to drag the motor has your slowing to a stop and then at last moment pull the clutch in. But even then the rpms will climb back up.

 

[vmsguy]

I wonder if the secondary "hot air" circuit could be screwed up.

I'm reluctant to suggest this, but what about removing the secondary air parts of the carb.

I just finished doing this on my bike, but only have 50-60 miles on it so far, so I don't want to speak too loudly. But so far my '84 seems to be running well.

What I did was; I removed the hot air box from the bottom of the carb assy. Then I cut a 1/8" piece of aluminum to cover the hole (there are two screws to hold it in place). Next, I found a machinist willing to do a little lathe work, and he machined the end (that go under the manifold) to match the end of the tube, except they were solid. He charged me $10.00 each, and had them done the next day.

I was cleaning the carbs anyway. so I figured 'why not?' I replaced some of the vacuum hose, making sure I put clamps everywere. Also replace air cut-off valve.

Like I said.. it seems better, but I don't have a lot of miles on it yet.

As I understand it, European bikes don't have these parts on them at all.

Good luck.