Motorized Bicycle Engine Kit Forum  

Sponsors



Go Back   Motorized Bicycle Engine Kit Forum > Bicycle Motor > 4 Stroke Bicycle Engines & Kits

4 Stroke Bicycle Engines & Kits 4 stroke engine kits are great if you want reliability or do not want to mix your oil and gas. Learn from each other how to get the most out of your 4 stroke bicycle engine

Reply
 
Thread Tools Display Modes
  #1  
Old 04-18-2017, 03:44 PM
nickR nickR is offline
Motorized Bicycle Newbie
 
Join Date: Apr 2017
Location: Los Angeles
Posts: 1
Default Predator 212 Mod Help

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.
Reply With Quote
  #2  
Old 04-18-2017, 06:18 PM
culvercityclassic's Avatar
culvercityclassic culvercityclassic is offline
Motorized Bicycle Elite Member
 
Join Date: Sep 2009
Location: Culver City, Ca
Posts: 2,989
Default Re: Predator 212 Mod Help

You can add the billet connecting rod to your list. You can find everything local at:

https://www.smallenginecams.com/
__________________
CulverCityClassic
wolfcreativecustoms.com
Reply With Quote
  #3  
Old 04-18-2017, 09:39 PM
Tony01's Avatar
Tony01 Tony01 is offline
Motorized Bicycle Elite Member
 
Join Date: Nov 2012
Location: San Jose, CA
Posts: 781
Default Re: Predator 212 Mod Help

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.
__________________
I don't always listen to Alice in Chains..... but when I do, SO DO THE NEIGHBORS
MxTrq clutch tuning | 212cc 2spd | CVT tuning
Reply With Quote
  #4  
Old 04-18-2017, 09:45 PM
Gbrebes's Avatar
Gbrebes Gbrebes is offline
Motorized Bicycle Elite Member
 
Join Date: Jul 2010
Location: Los angeles
Posts: 548
Default Re: Predator 212 Mod Help

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
Reply With Quote
  #5  
Old 04-20-2017, 10:11 AM
ultralight01's Avatar
ultralight01 ultralight01 is offline
Motorized Bicycle Elite Member
 
Join Date: Oct 2016
Location: Hood River, Oregon
Posts: 336
Default Re: Predator 212 Mod Help

^
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.
Reply With Quote
  #6  
Old 04-20-2017, 11:44 AM
TheNecromancer13 TheNecromancer13 is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2015
Location: Portland, Oregon
Posts: 561
Default Re: Predator 212 Mod Help

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.
__________________
125cc lifan build 79cc predator series
There's no replacement for displacement. Bigger is better, and too much is never enough.
Reply With Quote
  #7  
Old 04-21-2017, 12:00 AM
Scott.D.Lang's Avatar
Scott.D.Lang Scott.D.Lang is offline
Motorized Bicycle Elite Member
 
Join Date: Jan 2013
Location: Chicago
Posts: 406
Default Re: Predator 212 Mod Help

The best parts and info I have found is at ARC they build engines for racing Karts.
http://www.arcracing.com/
Reply With Quote
  #8  
Old 04-21-2017, 12:10 AM
Tony01's Avatar
Tony01 Tony01 is offline
Motorized Bicycle Elite Member
 
Join Date: Nov 2012
Location: San Jose, CA
Posts: 781
Default Re: Predator 212 Mod Help

A high revving 200 with a primary with 14t minimum in oil and it will last, and be fast as ****. Gotta think about the transmission too.
__________________
I don't always listen to Alice in Chains..... but when I do, SO DO THE NEIGHBORS
MxTrq clutch tuning | 212cc 2spd | CVT tuning

Last edited by Tony01; 04-21-2017 at 12:24 PM.
Reply With Quote
Reply

Tags
212 mod, predator

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 02:56 AM.


Sponsors

Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
MotorBicycling.com