anyone have jetting recommendation for the new 175cc super shifter engine. i’m haveing a lot of trouble getting it to even idle and it has no midrange controllability at all…it’s either flatout or nothing.
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Welcome Jim. You’re talking about the SKUSA 175 with the Tillotson carb right?
I have heard reports of the midrange being very abrupt. Some folks have elected to move the cable to a lower point on the throttle pedal, and/or add stronger springs.
Jordon Musser mentioned a similar experience in this video.
I don’t have a lot of 175 experience that I can relay yet, but whenever something comes up with a pump diaphragm carb, my question is… do you know what your pop off is set at?
Another thing to mention, you might know this, but for the benefit of others reading this…
The idle control on the Tilloston supplied with SSE is air control screw. So it works the opposite way of the other two (High and low) screws.
Turning the idle screw in/clockwise will richen the idle mixture
Turning the idle screw counter clockwise/left will richen the idle mixture.
thanks for the info but i have the dellorto…i can’t find any info on the newer tollitson yet…i probably would switch
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ok… found my problem with the 175cc jetting…NOTHING…not with jetting anyway…it turned out to be with the paddle shifter electronics. the paddle shifter kills the spark for a split second as i shift. i had the electronics mounted against the frame undere the radiator with 1/4 hard rubber padding to kill vibrations… was not enough. i jumpered out the ignition cutout relay and the engine ran great…no spitting no sputtering and pulled great thru the mid-range…but when i let the shifter relay do it’s thing…it raised all kind of he__. the engine would mis-fire…sputter…skip, go flat. would die between 5-8k rpm…and yet then sometime it would not… i took it to two pro’s i know and they were as perplexed as I, we tried every jet in the book…but it was not the carb. so i cut the two ty-wraps i had holding the shifter electronics bx loose and let it hang in mid air… the engine ran perfect. strap it back to the frame (even padded) and it would just screw the engine up big time. so now it’s mounted using two 8 inch long pieces of fuel line under the radiator and it’s strapped in the middle of these(big rubber bands)… track test two days and it’s now a real great kart…it does what i want …a whole new experience…I chased this problem for six months, but until Mike Gent at Shark Shifter put a timing light on the engine and we saw it act up…we had no clue. thanks to Mike and his guys and Don Holmbe at CMC Motors for all the help… NOW i have to learn how to drive this beast…but the smile is huge…
the resonance in the 5-8k range was enough to make the relay contacts chatter and bounce, so always be aware of vibrations…
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6 months? Must feel good finally putting that issue to rest. I would have given up on it.