Fluctuating Idle Issue

[Pro_Marinero]

Tried this 2012 VK Pro out finally. It was in excellent shape with very low miles but had sat for 6 or 7 years under a cover before I bought it last March. The carbs needed cleaning and it had a stuck piston ring. I soaked all cylinders in Marvel Mystery Oil and compression jumped to 180 across the board. I pulled the carbs and gave them a good cleaning, but I didn’t pull the diaphragms and needles. I removed the bowls, enrichener needles and all jets. I replaced the float needles with new. All pilot jets were plugged but I was able to clean them with air and carb cleaner (I didn’t ream them out). I also rebuilt both fuel pumps.

The sled runs great except for idling. It immediately fires up on the choke and will fluctuate between 2500-3000 until the temp light goes off if I leave the choke on full. Once the light goes off it idles around 3000 with full choke. I can take the choke off all the way and it will idle down. Once I ride and warm it up, the idle will go up to almost 3000 when I stop. I can adjust idle down to 1400, but when I stop again the idle will be up again. It seems like a vacuum leak, but I can’t find one anywhere. I’m going to pull the carbs again, clean them more thoroughly, and also sync them when I put them back on. However, is there some kind of cold feature on these carbs I’m unaware of? Like a thermowax air valve or the like? I’m guessing the fluctuating idle is a function of the ECU changing timing but it sounds like I might still have something plugged somewhere. I also might just get new pilots as these 45’s are so tiny it’s hard to tell if they’re totally clean. Thanks.

 

[74Nitro]

You're about to do what I was going to suggest anyway.
Sync carbs and new pilots.
Wouldn't hurt to do a leakdown test or compression test on the cylinders also.
There is a timing change for cold starts, but it reverts to the run map when the temp light goes off.