How do you get a 2 stroke to run backwards?

[UnknownStuntm...]

Well, for another one of my mental projects I want to know how to run a 2 stroke engine backwards. Has to be reliable, not fluked. Will be a petrol disc cutter, pull start. Looks like it's got a hall sensor or summat on the fan, I would guess I'll have to move that, and find a way to turn the pull start round. Anything else?

[binge]

If its running an oil pump, Then you will need to revert to premix, because in reverse the pump will become a sucker.


Apart from that, And possibly some advancing/retarding of the ignition timing, I am un-aware of anything else.


Of course, Wait it out and Kickstart will be around to bless you with some spectacular information about a 2 stroke engine from 1952 which was run backwards from the factory for some unknown reason.




Ben

[P.addy]

bump it backwards?

[The Artist]

bump it backwards, if it don't start, retard/advance the timing, can't remember which but make it spark later in the cycle so when run backwards, it will spark a bit earlier than it is currently.

My derbi senda 50 would bump backwards easily and didn't need adjusting, we rode it round the yard backwards, confused the neighbours.

[hmmmnz]

you need to retard the timing (essentially advance the timing when its running back wards) find tdc and find out where its pick up is in relation to that, then go the same distance post tdc,

wrap the cable from the pullstart the oppisite direction,
you'll probally have to reverse the 1 way lock on starter gear,
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[UnknownStuntm...]

The engine isn't a motorcycle engine unfortunately, it's a disc cutter. Like wot those big blokes cut kerbs up with. So it has to be pull started backwards. I think the timing issue is a fairly straightforward one, I'll try it later on and come back if I get any issues - cheers chaps.

[Blue_SV650S]

[B10Hazard]

[steven_191]

not sure about 2 strokes, but on more powerful 4 stroke engine the gudeon pin in the piston is offset to keep the piston more level during the up strokes.

if that run backwards it would be pushing the piston up at a very wrong angle.

but like i say, not sure if they are like that on the 2stroke.

[ms51ves3]

Truslack rode his Aprilia RS50 backwards at a meet once, unfortunately, I wasn't there.

[Kickstart]

Hi

Timing will need changing. Doubt a basic engine has any advance / retard so that makes it a bit easier. Starter depends on how it is set up. Con rod might be slightly offset on the piston, but suspect it will be useable (just might wear a bit quicker and be a touch down on power).

If it is enclosed with a fan to cool it then this might not draw air through properly when running backwards.

All the best

Keith
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