![2 stroke tuning forum 2 stroke tuning forum](https://p.vitalmx.com/photos/forums/2019/09/15/373148/s600_E4DFDA0E_E429_4A14_BCC3_43735D6E0B03.jpg)
Who may have tweaked old 2 smokes on a shoe string budget. Wish I still had that old copy of Cycle World with the expnsion chamber formula, we could design you a low RPM tuned pipe.
#2 stroke tuning forum crack#
Not like my Sherco that a crack of the throttle produces instant power and torque. I putt around through the creek and roots, then have to plan ahead to apply power early and hard to climb banks, hills and clear trees. I have the same issue with my Cub, not much power or displacement. Your advantage is light weight and small stature of bike, but to overcome the obsticles, you will find yourself wringing the throttle to get through.
![2 stroke tuning forum 2 stroke tuning forum](https://www.turbopacs.com/wp-content/uploads/2015/08/headimage420-399.gif)
Add to that you are geared way low, so when you need to pull your self up a bank, you will be winding this little motor out more than you think. Having riden trials, you don't have HP or CC's to get you out of situations, and you will find you will be reving more than a bigger bike will. You want it small enough to keep response quick when you crack the throttle, but big enough not to starve the motor when you build RPM. I suspect the Bantam is a pretty low ratio to start with and you can go a fair amount, but you will need to correct the timing to match.Īs far as the carb, you may have to experiment some. IF you have a heavy flywheel, you should be able to raise compression a fair amount without the motor coughing at low RPM. All this gives you more torque which you are sadly in little supply of. But widening will increase charge and scavenge. You don't want to mess with raising them unles you know how it will effect timing. Is there room to widen them slightly? Like 1/16" to 1/8" either direction and blending into the passage? This will cause a venturi effect when the charges go in and out to help scavenge. remember to round the edges of the valley on the crown to prevent hot spots.īefore you do this you can also look at how wide the intake and exhaust ports are. You can safely take the piston down to 1/16" from the ring groove. On the intake side it also creates added turbulence and an obstruction to incoming fuel air charge. That step is impeding intake and exhaust flow which robs performance. You can then take a file and make a ramp in the piston the width of the port to match the opening. If so mark the width of the port on the piston crown and how much overlap on the piston. Look up the exhaust port and see if the piston crown is covering the lower edge of the port. Run the piston down to BDC and look at the relationship of the piston to the ports. First you need to have the head and head pipe off and cylinder bolted in place. Someone has to have gone through this before and written it down somewhere.Īlan, being an old two stroker from days gone by, there are a number of tweaks we used to do to improve flow with the old dremel. Either I change the size of the ports, or change the length of the rod, well I could grind some off the edge of the piston. Is there an equation that will predict the answer.ĭuration again (seems to me) to be a major redo. Reed valve setups are available for Bantams, but man you are talking big bucks.Ĭompression I can fix - but what do I fix it to? I can mill 10, 15 thou off the head but what gives me the best improvement. He's a MIK fan but I'm not sure I want to go through trying to get one of those tuned correctly. I have several smaller Amals but they are all spigot mount. I am currently running a very small monoblock. Jennings (by reverse logic) does say a smaller carb might help. Flywheel with magnets, points and 1 wire to the plug.ĭoes a heavy flywheel actually increase power or just make it have better momentum at lower rpm? They are basically 2 stroke lawn mower engines. Only the late Bantams had light flywheels, all of the rest (my 59 included)had a very large flywheel.