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i need to know how to make a 2 stroke run backward? Answered

i am converting a pocket rocket from electric to run on a weed wacker engine but, the engine rotates the wrong way. any advice on how to get it to run the other way. i am most confused on how to change the timing to fire at the right time going backward. thanks

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rickharris (author)2010-04-07

Crankshaft may have been intended  - Actually it is a function of the port timing.

Some 2 strokes will run as well backwards as forwards if you change the starting mechanism  - electric motor, Cord pull etc to mke the engine turn backwards.

Some - especially those optimised for power or fuel consumption will only run one way see above.

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skaar (author)rickharris2011-03-24

yah, cause, unlike 4 strokes, there's likely no valves, just holes in the cylinder wall. the magic of making a 2 stroke like that run backwards, is taking the up/down piston actuated valving into up/down piston actuated valving.

with those cheap 2stroke bike motors, you just install them backward, change the timing of the ignition magnet/points, and they run backward perfectly. personally, i'd get something like the TIM-4 made up for it.

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kelseymh (author)2010-04-06

Gears.  Forward is defined by the way the pistons are connected to the camshaft.  You need an appropriate transmission to get reverse.

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Acepilot42 (author)kelseymh2010-04-07

dude 2 strokes dont have camshafts

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Re-design (author)Acepilot422010-04-07

dude, he miss-spoke.  He meant to say (type) crankshaft.

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lemonie (author)2010-04-07

I'd arrange the transmission so that you get the right result. Messing with the timing may be tricky, the compact casings can obstruct you moving things.

L

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seandogue (author)2010-04-07

At the risk of being obvious, could you turn the motor around 180 degrees and drive the load from the other side? (or is the shaft vertically oriented?)

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