xj600 no hot idle

Hi folks, new to the forum and need a little advice. Have a 94 XJ600S that I'm working on. It starts up just fine and seems to run down the road well, but after it warms up it will slowly lose rpms and eventually die at idle. On cold start it will sit there and idle all day if I let it, just will not idle when hot. I have replaced all 4 intake boots because they were cracked and would not idle at all even when cold, have replaced vacumm lines to petcock and fuel pump. Compression on all 4 holes is excellent. Have not sync'd carbs yet due to wrong size adapters for my gauges, will get that done tho. I am new to this bike but definately not new to bikes in general. Kinda scratching my head on this one. Any advise greatly appreciated. Thanks.

 

What kind of choke procedures do you use when starting? Full, half, no choke?

Ideal conditions: You should need a good bit of choke (at LEAST half) when starting it, and the choke completely closed after 10 or so minutes.

If you can start a bike cold with no choke, it will do exactly as you described -- run well for a little bit, and then not hold idle. You're running rich.

When's the last time your carbs were cleaned and inspected?

 

Hard to tell if they ever have, just got the bike and I have not been into them yet, but I have a feeling I will be shortly. Bike will start with either full or 1/2 choke when cold. Have not tried with no choke. I forgot to mention that when she is hot, have to open throttle to get her to start again.

 

When the engine has warmed up the idle should be adjusted to 1050 rpm. What happens when you try to adjust idle?

 

I can take it to around 2k rpm and it will run a little longer then start showing the same symptoms, dropping down some but it stays running longer.

 

Okay, update time. Went through the carbs today, found some crap in the bowls, etc. When I pulled them down, I counted 3 to 3 1/2 turns out on the mixture needles. I reinstalled them the same. Not sure what the recommended setting is for this one. Once I got fuel back into the bowls, she started up just fine and took her for a spin to get her good and warm. Ran much better, no hesitation and rpms came up a lot quicker now. Got back to the shop and sure enough, same thing. slowly dropping idle rpm until dies. Any further thoughts? Needle and seats all looked good with no ring on needle tip.