Hi All,

 

I've had 5 sherco's (mainly 2005's and 2006's)  over the last few years, and nearly everyone kicked back.  I've tried retarding the timing, but it doesn't really improve.

 

The only thing that fixed one bike was a new Stator.  Only problem is, the bike I have now has had a stator recently but even retarding the ignition, it still kicksback.

 

Is it just a quirk of Shercos or am I missing something.  I would appear from reading posts on here that its really hit and miss, some bikes kickback, some bikes dont..

 

Any other pointers, let me know...

 

Cheers,

 

Wayne.

Edited April 30, 201511 yr by waynerobshaw

I have replaced the stator on my 2005 290 but I wasn't aware of it kicking back either before or after the change out. The reason I changed the  bad stator was because the timing failed to advance correctly as the revs increased, oddly though; I couldn't alter the timing, regardless of where I set the back-plate?

My 2011 290 backfires every once in a while. Can never tell why or when it happens. Good fun when you're in a queue for a section - gives fellow competitors a shock. Usually starts fine and runs ditto so I just put up with it!!

Usually kickback on starting is caused by not pressing the  kickstart firmly enough. Some people having had a kickback (that can hurt) tend to be a bit timid in future and that makes the problem worse.

 

Strictly speaking a backfire cannot happen on a reed valve two stoke, the fire cannot get back past the reed valve.

 

What people often call a backfire is a mistimed combustion in the combustion chamber or an unburnt fuel combustion in the exhaust. You need to know which it is before trying to fix it.

All I know is with the 250 Ninja I used to own, I could turn the run/stop switch off, twist the throttle  and turn the run/stop switch on would make it produce a really nice BANG!  

 

Sometimes I could time it just right so as I was exiting from under an overpass my buddy would be under the overpass when it would BANG!  quite the echo it would have also.

 

fun times

Edited May 1, 201511 yr by zippy

Kickback and backfire are not isolated to Shercos. Ignition timing is set in advance of TDC and a light prod may kick the piston back down!

 

If ignition is advanced to an optimized position for power, which many factory settings are, you are then closer to opening the exhaust port while the fuel is still exploding and sending the flame into the exhaust which may well still contain unburnt fuel vapors from the last shutdown(when you stopped the flame with the motor turning). This can create quite a bang! (backfire in exhaust, not intake!)

 

A slight retard from factory timing of about 3mm on the stator plate will indeed reduce likelihood of kickback with minimal change in performance for the average bloke. This also reduces stalling tendencies at low revs. I find it a preferred setting.

 

Do not lightly kick the bike with the bars turned to the right! It will drive your friggin knee right into the bars and hurt like hell!!!

 

Ham2 don't know just how to measure this stuff, and Zipper just does it for fun!

I'm referred to the engine kicking the starter back and not back firing...I must admit I'm more gentle on kicking the Sherco over my Gassers, the kickstart seem so small and brittle...I'll give it my full weight from now on ;-)

 

Not wanting to start a war but I've never had a GasGas kick back ever...over 20 different bikes and years!

Edited May 1, 201511 yr by waynerobshaw

Funny you should compare kicking a sherco & gas gas, in my experience the sherco has the far stronger mechanism internally but yes I have snapped 1 sherco lever & bent another in 10 years, the gas gas kickstart with the large knuckle is a stronger design

The older Sherco Kickstarts were much better, I bent mine on my 300 and replaced it with an 02 unit.

 

You have to give the Sherco a good kick, But engage the gear 1st by holding pressure then kicking through.

 

It easy to kick them too gently through fear of the gear slipping ang jaring your knee.

 

I had my old bike make some loud bangs every so often but it never kicked back through the lever.

all of my ty monos back fired. some did to the point of imploding the reeds.

-- Biff