Fiddling with my rings and carb
I'm collecting info for the big bore install in the near future ( thanks to a gent who lent me a big bore liberty)
I thought it would be a good idea to check the ring end gap rather than just relying on the factory getting it right.
Is there a rule of thumb setting for the end gap of two stroke rings?
I have found one rule of 0.10mm-0.12mm of end gap to every Inch of bore.
Considering its a mill gap measurement for an imperial bore measurement I thought it sounded like a 6 fingered solution to a 5 fingered problem...or is that a 5 fingered solution to a 6 fingered problem?
Is it normal to do a small chamfer on the ports with some emery paper rather than risk leaving them sharp?
Thanks for any input
i dont think i have filed a ring end yet
but its good practise to check - convert the imperial rule and measure it. my feeler gauges are both imperial and metric anyway.
good practise is to chamfer port edges, either with a file if you can get at it, a rotary tool (dremel) if you are confident you can hold on to it - or emery cloth if you want to be there all day - radius edges dont effect performance much and your rings will last much longer
Your liberty barrel is probably alloy not iron? why are you messing around with it?
Thanks Matt
Its a cast barrel probably a DR not a top end unit at all but produces its power lower in the rev range, its known to last and uses the original head. (I'm staying with the limited CDI for now)
On the westie run Ritchie and I swapped scoots, his Liberty and my Jog (50cc), for the run into Scoot E motion as you know he has his liberty sorted with its 70cc kit, so the fettling seed was set.
What do you think of this idea for running it in?
http://www.mototuneusa.com/break_in_secrets.htm
It just seems so wrong but I can see some merit in the method.
It seems its being used on worked two strokes with good results. I used the method Yamaha had in the manual so it will be interesting to see what it looks like, taking into consideration the carbon from non racing grade fuel.
i have broken in an engine on the race track
you have to be confident though that your piston to barrel clearance is correct. that your carb set up is right, that your ignition is right, and that your piston to head clearance is right. if you are not confident, then i would check everything twice before you start thrashing it....most importantly your bore clearance and jetting.
It can be done, thrashing them to run them in, race tracks are good because you dont have constant throttle settings...but if you are guessing, you are wasting your time and money