79cc Predator Build Progress

GoldenMotor.com
Jan 21, 2015
610
25
18
Portland, Oregon
Got the new sprocket today, it now has a top speed of about 45ish (still can't tell cause the radar sign in my neighborhood just says "SLOW DOWN" if you go above 40 lol) and it also has enough torque that when I went from nothing to full throttle while rolling along at about 3mph it did a wheelie. It can also take a steep hill at 25mph no problem, take off from a standing start, and accelerate uphill. Overall, I'm very happy with it. I was wondering, would anyone like to see me make an extremely detailed tutorial on how to make one exactly like mine? I'm thinking about making an instructable...
 

Tony01

Well-Known Member
Nov 28, 2012
1,730
1,722
113
sf bay area
Got the new sprocket today, it now has a top speed of about 45ish (still can't tell cause the radar sign in my neighborhood just says "SLOW DOWN" if you go above 40 lol) and it also has enough torque that when I went from nothing to full throttle while rolling along at about 3mph it did a wheelie. It can also take a steep hill at 25mph no problem, take off from a standing start, and accelerate uphill. Overall, I'm very happy with it. I was wondering, would anyone like to see me make an extremely detailed tutorial on how to make one exactly like mine? I'm thinking about making an instructable...
Sounds about right. Assuming your wheels are 700c, your gear ratio equivalent of a 26" wheel is 12.4, which is approximately the same as my first gear at 12.2. Yup the low speed uphill performance is similar. Accelerate from a stop uphill... Nice right? :) So to go 45mph your engine turns at 7350rpm? That's pretty good for a stock predator. On the briggs 3.5hp the engine floats the valves at 6200 before it ever gets close to exploding the flywheel.. But 7k could damage parts on your engine without upgrades. Just an FYI! Possibly think about installing stronger valve springs as floating the valves on an OHV may bend them I've heard, and the flywheel is running at double what the engine speed was when you bought it.