doodlebug mini bike original engine
A jackshaft kit from ProMod is the only sensable thing I know of, it's around $100 and will help with takeoff and hills but top speed will be limited still. A 6.5 swap is best if you are an experienced rider and wont be letting young unexperienced riders on the thing. My kids killed a couple of stock DB engines, they are pretty poor quality and messing with them is not advised!
You gotta keep inexperienced riders away from your stuff FMC! Now my blue DB has put some folks on thier kiester, but damage has been minimal! And only one wrecked it right away, the dude I built it for got on it, cracked the throttle and it wheelied out from under him immediately! He backed out of the deal and I've had it ever since! I have no regrets, it introduced me to clones! I had it's non painted twin, I had bought them both and wanted to do as I had for years. Just stick a B&S on it and ride! I did put a 5hp B&S on the other one and loved it, but I paid $125 for both clapped out minibikes and while the 5hp was off for a carb rebuild I sold the roller for $150! And I regret it!
nightstocker, use the search button. There are plenty of threads on here on how to tweak a few things on the 2.8 to get a little more speed out of it. The torque will never be there unless you upgrade or add a jack shaft, but there are a few things out there.
Did you back out the throttle stop screw? Put at least 20 to 30 lbs of pressure in the tires. That alone should get you running around 27-28 mph.
Did you back out the throttle stop screw? Put at least 20 to 30 lbs of pressure in the tires. That alone should get you running around 27-28 mph.