cshelly cobra
Member
hi guys, as you can tell im working on a kt100 for hot lapping. what passages in the walbro should I enlarge to get more fuel to a high compression semi ported piped kt100, thanks, chuck
thank you sundog.You could open up the low jet a tiny bit and smooth the casting seam in the venturi. Run your fulcrum arm a little high and set your pop off to 9.
thanks jon, great info. I will keep this info with my other kt stuff. chuckYou really don't need to do anything with the fuel passageways if running gas. The carbs capable of getting plenty rich , even with a radical SA from what I've seen. Now if you want to unleash all the potential of your port work, the carb needs more airflow. If you can, bore the venturi to around 1.00 and the throttle bore to handle a 1.100 shutter. There's a lot more to it than that but it will take a stocker from 65 cfm to 90. Hot lap ? Heck yeah.
thanks so much jon. that sounds much easier. I am looking forward to tinkering with my kt. what a great site! chuckThat may be more than what you want to get into but since it's non tec , it's easy to pick up airflow even with no bore work. Take the throttle shaft out and carefully cut the topside off , the button head screw will set right on the shutter. Reducing the profile of the butterfly and throttle shaft assembly is a major factor when you try to hod rod these butterfly carbs.
thanks jon, those pictures of the carbs look like works of art. the second picture that carb looks much bigger to me. thanks chuckHere's what can be done with a WB3A. 1.100 shutter out of a WB20, anything bigger will break out. A Tilly 380 shutter at 1.125 will work with a little patching . You'll want to leave the venturi about .100 smaller than the throttle bore to have a strong venturi effect while positioning the V right at the high side dump for max signal. The very best flow was achieved with the old filter cup, with a full radius at the edge vs a velocity stack. Build a high flow shaft assembly and all that will get you 90 cfm with a stocker moving 65.
These 2 stroker engines will be for sale once I check them this weekend or next week. Unfortunately as many of you know we lost Chuck (nobozos) and his wife in a car accident and his family asked me to help selling his racing stuff. Plenty of Yamaha stuff. I'll keep everyone updated. It is tough for me to do this but I want to hrlp as much as I can.Yo Chuck this might be easier and cheaper later Chuck.
10-4 rainmanThese 2 stroker engines will be for sale once I check them this weekend or next week. Unfortunately as many of you know we lost Chuck (nobozos) and his wife in a car accident and his family asked me to help selling his racing stuff. Plenty of Yamaha stuff. I'll keep everyone updated. It is tough for me to do this but I want to hrlp as much as I can.