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Yfz450 Fcr Hot Start Cable Mod - Suzuki Z400 Forum : Z400 Forums
Hey there guys,
My buddy N8 came up with this idea as we were getting ready to upgrade carbs. He snagged a 06 and I snagged an 08 FCR from YFZ450's and we were tearing them down, cleaning, inspecting, doing the tps mod, accel pump mod, and test fitting the boot. He said he really was wanting to have the hot start option, and at least on the FCR's we have, 06-08 FCR from the YFZ, the hot start is the vertical port above the choke with a black plastic screw cap. (Looking down at the carb on the bike between the frame rails it is capped off. I suppose it wasn't put on with a cable from the factory but there as an option)
The hot start plunger is in there as well as the spring that is under the cap holding it in the fully seated position. I thought the hot start port was the vertical port just above the choke port of a FCR that is blocked off with an aluminum freeze plug style plug, and I know other FCR's are set up this way, or with the choke in the upper one and a hot start pull knob in the lower, but we looked up a exploded diagram and parts list of the YFZ450 carb and sure enough the hot start cable hook up is the one we were looking at. To hook it up you would need a cable and perch we figured.
Then he noticed that the factory Z choke cable had the same black plastic threaded end as the FCR hot start port cap and had a spring and plunger just like the FCR hot start set up and we wondered... humm.. would this work. I took my hot start block off screw cap out, removed the spring and plunger, next I took the plunger and spring off of the end of the factory Z choke cable, set them aside and put the FCR hot start plunger and spring on the factory Z choke cable end. I screwed it in and it worked like a factory option. I took it back out and measured the distance from the mouth of the port to the bottom of the port, and measured the distance from the seating face of the choke cable cap to the end of the hot start plunger to be certain that when the "choke", now hot start lever was off, the plunger would be fully seated and it was perfect. I listened to the plunger with a mechanics stethoscope and heard it go from completely seated in the off to completely open in the on position using the "choke" now hot start lever. To triple check I took out the FCR choke plunger and there is a small port that connects from the hot start port to the choke port inside and I operated the hot start back and forth and could feel / hear air moving back and forth through there. The stock Z cable has a 90* end on it so it should tuck right in place with no problem once the plastics and seat are back on. This will be the last step I haven't done yet to confirm the whole thing is a success, but I really don't think there will be any problem there. My Z and his KFX are both 05's.
I haven't seen this covered in any other posts, and I do see guys fitting up different cables from different bikes to try and put together a hot start cable. So if you haven't removed and thrown away your factory Z choke cable then dig it back out because this looks like it's going to work.