hey all done alot of engine work before on previous bikes such as scooters and geared am6 engines just started on a dt125r engine by raising the ports by a few mm whats your opinions and no it wont be a bodge job lol done plenty before :)
__________________
dtr 125 engine in derbi senda full arrow exhaust pipe 30mm mikuni carb full power cdi power valve fully open
If youve just put another base gasket under the cylinder then the ports will have been raised but the compression will be lower. If this has been done on a part worn barrel the rings will wear quicker as they now have to go over a step in the cylinder made by the rings prior to the mod at the bottom of the stroke.
If you've raised the ports by machining them then fair play to you as theres no going back!
There's no point in looking to raise the exhaust port as thats what the power valve does.
The only stuff I have done on the one I am building at the moment is to make sure the transfer ports match the crankcase, all ports blended and casting marks removed, the tops of the transfer ports are the same height from the top of the cylinder, the cylinder head squish clearance is set right and the reed stops are set to the right dimension. Also checking cylinder to piston clearance and ring end gap.
Anyway, you say youve already done it so let us know what it runs like!!
ye only done the exhaust port so far then i started doing the power valve too a little bit all am doing is raising the ports not the cylinder its self i will let u know how it goes and i will post a few tests
__________________
dtr 125 engine in derbi senda full arrow exhaust pipe 30mm mikuni carb full power cdi power valve fully open
