make a 26cc rc engine run in reverse?? for motorised bike and a goped??

Okay, goped engines spin in the same direction as Happy Time/China Girl engines.

Yeah they do. But the drive gear is on the other side. And ya just can't 'turn it around'. And a 4 stroke gearbox won't fit on it without modifying it. You could always jackshaft it to the other side. Or possibly use a freewheel on the pedal crank (SBP) and drive it from the pedal side.
Big Red.
 
the goped sport runs the opposite way to the chinese bike engines (spins left) the cy 460, does that spin to the left? if yes ill get one of them for the bike and for the goped. but the cy26cc engines i have run to the right but then bike and goped will go back wards haha. and no clutch, just direct spindle drive, and no pullstart is used either. as for retiming a 26cc cy to go in reverse do u know where i can gets reverse magneto? so it fires properly? thanks, or any details on a left spinning engines? cheers
 
Yeah they do. But the drive gear is on the other side. And ya just can't 'turn it around'. And a 4 stroke gearbox won't fit on it without modifying it. You could always jackshaft it to the other side. Or possibly use a freewheel on the pedal crank (SBP) and drive it from the pedal side.
Big Red.

Please don't not mistake the engine crankshaft with the 5:1 transmission drive gear on a goped engine.
The 5:1 goped transmission bolts onto the goped engine. It is NOT part of the goped engine.
If the drive gear is on the other side, just 'turn it around'.
Just turn the engine around or swap the 3:1 tranny with a 5:1 tranny.
You can bolt on a 3:1 tranny and face the clutch to the left.
A 3:1 tranny does not reverse engine output rotation, like the 5:1 tranny does.
Run a 10t on the 3:1 tranny, a 50t wheel sprocket and you get 15:1.
Or you can run the 3:1 tranny, jackshaft it to a 24t sprocket.
On the right side jack a 10t gear to a 44t chainring.
With a 24t inside chainring and 12t 8th gear, final drive is 15.12:1,
with a 1st gear (34t) of 42.84:1.

Orrrrr you can just 'turn it around'. Face the clutch to the right. (I did this.)
Install a 5:1 tranny w/an 11t sprocket.
Chain that to a 72t chainring.
With a 24t inside chainring, final drive is 16.36:1.
First gear w/34t is 46.36:1.

You're right, I don't know how a 2-stroke engine would fit a 4-stroke gearbox.
However a 4-stroke engine w/a 76mm clutch will fit a 3:1 or 5:1 gearbox.
 
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the goped sport runs the opposite way to the chinese bike engines (spins left) the cy 460, does that spin to the left? if yes ill get one of them for the bike and for the goped. but the cy26cc engines i have run to the right but then bike and goped will go back wards haha. and no clutch, just direct spindle drive, and no pullstart is used either. as for retiming a 26cc cy to go in reverse do u know where i can gets reverse magneto? so it fires properly? thanks, or any details on a left spinning engines? cheers


Correct me if I'm wrong.
If I stare at the engine clutch, what does "spin left" mean, clockwise or counterclockwise?
CY460 engines spin CCW. as does Tanaka, Mitsubishi, Robin/Subaru and pocket bike engines.
I know this for a fact, as I have run all of these engines.
I will presume that most goped and weedwhacker engines spin CCW.
You must remember that the 5:1 pocketbike/goped trannies REVERSE the drive gear's rotation.

I cannot say this any simpler.
 
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theres no transmission on the engine, its a goped sport geo (thats the same engine/setup i need for bike) its just a spindle on the crankshaft-held on by a bolt. that runs on the wheel :)
 
theres no transmission on the engine, its a goped sport geo (thats the same engine/setup i need for bike) its just a spindle on the crankshaft-held on by a bolt. that runs on the wheel :)


If you cannot relocate the engine, remove the spindle and put a belt or sprocket drive.

Then the tire will turn correctly.
 
thanks, but the only was is to get it to run in reverse, i don't wanna do any modifications. i know u can run them in reverse with only changing timing, how do i do hat tho? just a different magneto? any mag recommendations thanks
 
how many times can we say this? do you not read anything these people are posting?

THERE ARE NO MAGNETOS AVAILABLE FOR COUNTER ROTATING AN ENGINE THAT IS INTENDED TO ONLY ROTATE ONE WAY AND HAS BEEN MASS PRODUCED AS SUCH.

anything normally fitted with a small engine is designed with the point in mind that all engines of similar design, regardless of manufacturer, all rotate in one direction. be it a generator, a brushcutter, a pump, or a motorised pushy.

you proved you arent a designer by ignoring the basics.

run it on nitro, and give it a glow plug. then it doesnt matter, cus it doesnt have spark ignition.

yes, two strokes will run both ways (as long as they are piston or reed ported). so will standard diesel fourstrokes if you can live with exhaust being driven back through the aircleaner... both these motors can do it just by "bouncing back" against compression. a petrol 4stroke will do it with cam changes. get over it, its well documented in boats and early cars.

kickback is well known in aircraft with no starters. watch the old movies carefully. they smack the prop backwards against compression so it kicks and starts running the right way. works on RC 4strokes, doesnt on RC twostrokes(which can seldom run backwards as they are normally ported through the crankshaft, a variation of drum induction. cox049 etc are the exceptions) so the same can apply when stalled. they kickback against compression and will start running backwards under the right conditions.

a cox 049 can splutter at 25000 rpm and suddenly its running in reverse without you realising til its throttled down!

the majority of manufacturers stick to a standard pattern, and dont deviate.


other than flipping the motor which involves a redesign, and awknowledging you made a fundamental booboo, you could try circuit forensics.

depot your magneto. work out its internals. then reassemble, in reverse.


cdi.jpg

pretty basic.

all you gotta do is bear in mind if its a N or S pole first, which way the coils are wound so will it produce a negative or positive charge current triggered by a opposite trigger current. and then make sure the magnets line up to cause firing at the correct time still, which they wont because the magnetos are usually assymetrical, so always have the advance built in by design.

i have an old kawasaki brushcutter here that uses a symmetrical magneto. that can be flipped and still wont run both ways as the flywheel needs to be flipped somehow...


you want the last suggestion?


re locate the keyway on the crankshaft/flywheel.

the easiest and most logical option. work out where it is in relation to TDC and add or subtract twice the existing advance to get the new location.

that should work but you may experience polarity issues with the charge currents... some systems will, some wont.

you still havent explained how youll start it in reverse... cus a pullstart wont work anymore.
 
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