HF 79cc

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massdrive

New Member
Oct 3, 2013
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Las Vegas
Harbor Freight has there 212cc and 79cc predator engines on sale this weekend for $99.99 and I have a 25% off coupon. I know many here have used the 212cc predator, but what about the 79cc? The 212 just looks gynormus, where as the 79 isn't much larger than a china girl. I don't want to build a racer I just want to put a 4 stroke in one of my bikes. The 79 is rated at 3 hp. What kind reliable power can be created? Does anyone have advise or opinions?
 

Dan

Staff
May 25, 2008
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Moosylvania
Really like the 79's. They are torque monsters and very reliable. Never bent or broke spokes on cheap wheels until I started using HFs.

One thing about em is the starting mechanism will fail pretty quickly if ya start em by just wailing on the pull cord.

Basic stuff but you gently pull the cord until resistance is felt. Allow the cord to retract. (not snap back) then a long deliberate and forceful pull. Repeat if necessary.

I try to swish the oil a time or 2 and move the piston before starting just to be kind to the engine but is probably not needed.
 
Last edited:

racie35

Active Member
Nov 17, 2012
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usa
Other than needing a clutch..I don't get why people think they're more expensive. Considering how good they run and trying to match their torque would be quite a chore for a ht.
 

GearNut

Active Member
Aug 19, 2009
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San Diego, Kaliforgnia
Let me add to Dan's tutorial that when you go to do the second "start" pull, you pull the starter gently until you feel the starter pawls engage (you will feel the resistance when they do) and without letting the starter rope go slack do your long deliberate and forceful pull. This will gently pre-load the starter mechanism instead of slamming it into position.
 

massdrive

New Member
Oct 3, 2013
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Las Vegas
Thanks guy's I appreciate the advise on how to start an engine that I'm thinking about buying. How about some advise on how to mount it, and drive train options, carburetor options, up grades and such?
 

GearNut

Active Member
Aug 19, 2009
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San Diego, Kaliforgnia
Mounting it is typically a DIY endavor.
You can get a plain flat plate from AGK or you can make your own mounting plate.
The AGK plate is designed to use the mounts brackets from a Typical HuaSheng 142F style mount. You can also weld it to the frame or make your own mounting brackets/ clamps for it.

AGK also sells a jack shaft assembly to fit the HF79.
EZ Motorbike sells the Qmatic drilled to fit the HF79. Just tell them what you want it for before ordering or by default you will get one drilled for the HuaSheng 142F.

AGK sells all sorts of hop up parts for the HF79, too many to list here.
If you are skilled enough to understand what the techniques and risks are, you can also do some things yourself such as decking the head to increase compression and fitting a motorcycle or scooter carburetor.

Many folks here have successfully installed a lawnmower/ edger engine in a bicycle frame with no kit parts what so ever. Check out these forums for ideas and info:
http://motorbicycling.com/forumdisplay.php?f=6
http://motorbicycling.com/forumdisplay.php?f=36
Yes, there are plenty of threads to weed through...
 

massdrive

New Member
Oct 3, 2013
454
3
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Las Vegas
Thank you for the useful information. I went ahead and bought the HF 79cc, just couldn't stop myself. So now I'm thinking about a new build!!!!
dance1
 

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