OK. I like your project bike, even though I'm horrified by the paint scheme you are proposing ( lol ). Bear with me here for a bit as I'm unfamiliar with the post 86 Ventures. Your original 83 brake anti-dive system was activated by hydraulic pressure . Each anti-dive valve was hooked up to the front caliper next to it. I suspect that the newer model you have is similar. One side would be electrically hooked to the handlebar brake stop light switch and the other to the foot brake stop light switch. One commenter suggested that with progressive springs, that entire system is unnecessary. I agree but short of taking your front end apart I do not know how you would check. Two other things you should know, if you haven't figured it out yet,: The front end of the 86 and up bikes used a larger diameter fork tube than the earlier bikes and it is more ridged and stronger than the earlier design. ( So you should keep it ) In addition, you do not have the original brakes on your front end but the much better calipers from one of the later Yamaha "Ninja" type bikes. Something like a YZ1000 . Some person with more knowledge will step in shortly to identify the exact model or you can wander through the hundreds of posts here to find it. Your calipers look nothing like the calipers on my 86 parts bike. If you cannot get your air suspension system running, I have a spare one. Many people here have spare parts they might donate for the cost of postage. PM me if you want it. There is one more dreary and sad thing I must inform you of. In the FACTORY MANUAL, for 83 to 85 Ventures , the intake and exhaust valve clearances are REVERSED. This means that the exhaust valves are too tight and the intakes are too loose. If you intend to keep the bike you must check this. If you doubt me, check out the used motors on e-bay. It is frequently noted the compression is low and this is why.