revers start?

[FireHead]

You know when u go down a hill, your engine is off put it in 2nd and let go of the clutch the engine jumps to life, I was wondering; can u do that in revers??? basicly run ure shee down a hill goin backwards, and then let go of the clutch would the engine jump into life, but fireing the otherway around? Though I wont suggest trying it do any of u guyz know of any facts bout this?

 

P.S sry for not posting up here in a while, it gets upto 50*C over here in the summer (march-mid nov)

It works in theory, but your kickstart system is basically setup to only turn one way, so you;d have to modify it. From my experience, the whole reverse deal is not practical on a Banshee, but if you like fiddling with stuff and have the resources to do it, then go for it. On the other hand, I have had a couple engines go into reverse when I was starting them by motoring my dyno, this usually happens when I have the timing messed up or my dyno GC messed up. I wound up with a broken clutch cover in all of those instances. :geek:

[sa3ood_banshee]

lol so it seems shee doesnt like walking backwards :wink: :wink: :wink:

 

 

 

sa3ood

[Bigairee]

There was a member on here several years ago that said when he started his banshee and tried to take off it would go in reverse. Met him at a ride and sure enough it was still doing it. The flywheel key had sheared and let the timing change enough to run in reverse. Any time he put it in gear and tried to move it would go in reverse.

[banshee_boy09]

Doesnt the gas gas 300 two stroke atv have reverse....I have a dirtwheels magazine laying around, it was pix of it at a sand sport show or something like that..they said you pull the clutch in and hold a red buttom down for like 1-2 seconds and the moter stalls, and then fires backwards or something like that.

[Bigairee]

Doesnt the gas gas 300 two stroke atv have reverse....I have a dirtwheels magazine laying around, it was pix of it at a sand sport show or something like that..they said you pull the clutch in and hold a red buttom down for like 1-2 seconds and the moter stalls, and then fires backwards or something like that.

 

Any sled guys here. I think some of them work on the same principle.

[felcon edition banshee]

banshee won't run backwards unless you change the ignition timing or get the engine revving really high before turning the ignition on.

 

2 strokes, as well as all other engines, have ignition timing. for the banshee, this means around 17 degrees before top dead centre at idle, for a stock motor. that mean the plug is firing before the piston goes to the top of the cylinder. if you run the motor backwards, it would have timing of 17 degrees after top dead center, which means the plug fires but nothing happens because the piston is already going down a significant ammount.

 

this is unique in the engine world because 4 stroke gas alcohol and diesel engines all start their timing curve with a relatively low ammount of advance at idle, and it gradually increases the timing as the rpm's rise. 2 strokes are unique in that they work exactly the opposite, starting the timing curve with a high degree of advance which lessens as the rpm's rise toward redline.

 

because a 2 stroke ignition timing curve is unique in that it starts advanced and gradually retards from that point as the rpm's rize, the banshee has ignition timing of around 2 degrees btdc at high rpm's. this is close enough to top dead centre that if the motor was run backwards to a high rpm and the ignition turned on, it could theoretically run backwards, but only at high rpm's and it would be down on power because its running severely retarded timing. if you let off the throttle and the rpm's dropped the motor would quit running, possibly violently without first flicking the kill switch.

 

theoretically, the crankshaft, rods, pistons, top end, carburettors, exhaust pipes, etc can all work backwards like this without any consequences because a 2 stroke has no cam or vales, it actually can run backwards. if you hand crank the engine foreward or backwards, the carbs and reeds still pull air through them in the same direction. makes no difference which way you spin the motor. there have been plenty of 2 strokes built with adjustable timing to run forwards or backwards. model airplanes come to mind specifically here. you can run a model airplane 2 stroke backwards or forwards simply by which direction you spin the prop to start it.

 

IF you change the ignition timing on a banshee to account for this you could run it backwards. if you don't, then you wont be able to run it backwards. although you might get an occasional pop or backfire that might destroy things.

 

i dont know what the transmission would do if you tried to shift while the engine was running in reverse though. maybe nothing. maybe it would grenade.

 

 

thanx i know alot more about all that after u posted this book^^^ lol u gt alot fo time on ure hands but nicely put and explaned