HF question

racie35

racie35

Active Member
do all the harbor freight predator engines require the pulleys etc to be mounted on the right side of the bike?
That is.. with the cylinder leaning forward.
 
if the cylinder is angled forward, the drive shaft is on the right side of the engine
I believe any that are oriented that way are friction drive only,,,,the shaft would be turning the wrong direction otherwise ;)
 
I guess my question should be do any of them rotate a different direction allowing that cylinder orientation.....like a whizzer engine
 
racie35 said:
I guess my question should be do any of them rotate a different direction allowing that cylinder orientation.....like a whizzer engine
Click to expand...

I havnt seen a 79cc but the 212 can be mounted vertically so the cylinder is facing up alot of guys are doing that way.
 
you might be able to get a two stroke briggs or tehcumse to run the opposite direction, i never tried it so i dont know if you can,
 
moonerdizzle said:
you might be able to get a two stroke briggs or tehcumse to run the opposite direction, i never tried it so i dont know if you can,
Click to expand...

All you need to do to get a 2 stroke to run backwards is advance the ignition "too far". However to avoid damaging the engine this must still be tuned to the point where the spark occurs at the correct degree of flywheel rotation.
Otherwise a pre-ignition condition could result and trash the piston and connecting rod, or the ignition could occur too late in the power cycle and you will be wasting power and fuel.
 
im not gonna be messing with the 2 strokes....just was figuring the cylinder forward on the 4s would let it cool easier and have the drive on the left...seems they all turn the wrong way though?
 
Yup.
One would need to install a cam shaft that is ground to accommodate the reversal of rotation, set the ignition timing precisely to accommodate reverse rotation and install a pull start that pulls the other direction.

Splash oiling might be an issue for OHC engines too as the splash would not go where it was engineered to go.
 
It could be done, but would require a counter shaft setup...

Center pulley is the counter shaft (jack shaft) to change the rotation so it will work.
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Not my bike and it really is a friction drive setup.
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I think I have it figured out.....HF 212...shaft out the left side....cyl facing back should be direct....easy to clutch up etc
 
racie35 said:
do most of you feel a 212 is overkill for these builds? 99cc would be better?
Click to expand...

Just slightly.

99cc would be a better. If you want more power from the 99cc, you can get some limited performance parts from AGK.

Good Luck,

Chris
AKA: BigBlue
 
I'll look into that....price difference isn't enough to make one choose either....I may set this bike p electric till I gather up the needed stuff, then throw it at it
 
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