So I just bought two Harbor Freight Predator 212cc engines, one for a mini bike and another for a go kart. I am planning on performing several mods, such as governor removal, air filter and header upgrade, etc. I just wanted to know, after removing the governor, since the engine isn't optimized for higher rpms, what should I upgrade to improve life span? I heard that it is good to change the valve springs and billet flywheels but I would like more information on that.
culvercityclassic
Well-Known Member
You can add the billet connecting rod to your list. You can find everything local at:
https://www.smallenginecams.com/
https://www.smallenginecams.com/
Tony01
Well-Known Member
The stock springs will limit your max rpm to a safe one for the stock parts. My motor is still good after over 5000mi with no mods really, removed governor ported and high flow intake and exhaust. Valve springs are a little tired now and it won't rev past about 4800. You don't need a billet rod and flywheel until you upgrade the valve springs. You can even run the cheater springs they use in the sealed karting classes without needed billet parts. Most my bike problems come from frame cracks and chains eating sprockets.
Gbrebes
Well-Known Member
If you remove the govenor, the billet rod and flywheel are necessary because the stock components may fail at higher rpms. The stiffer valve springs allow you to attain rpms above 5,000, since the stock springs would begin to "float" the valves at around 5,000.
If you get these extra parts, I would also recommend a mikuni carb from 22mm up to a 26mm. With all of these mods, including 18lb. springs, you should be able to attain 7,000 rpms with plenty of low end power. Be careful on the mini bike though, wheelies upon take off would be most likely.
Good luck,
Gilbert
If you get these extra parts, I would also recommend a mikuni carb from 22mm up to a 26mm. With all of these mods, including 18lb. springs, you should be able to attain 7,000 rpms with plenty of low end power. Be careful on the mini bike though, wheelies upon take off would be most likely.
Good luck,
Gilbert
ultralight01
New Member
^
That's considered an extra mod and will be about $200 extra.
Just having no governor and the stock parts will last a very long time and you'll havesome crazy speed.
That's considered an extra mod and will be about $200 extra.
Just having no governor and the stock parts will last a very long time and you'll havesome crazy speed.
TheNecromancer13
Active Member
As long as you don't go full throttle down a long, steep hill, you should be able to leave it stock other than governor removal and you shouldn't blow anything up.
Scott.D.Lang
Member
The best parts and info I have found is at ARC they build engines for racing Karts.
http://www.arcracing.com/
http://www.arcracing.com/