Hey guys,
I installed a new block with no port mods, but I used the piston that has the cut skirt (clears intake all the way at TDC), and I didn't use a base gasket or head gasket. I didn't intentionally shave down the head, but I did take a bit off by sanding it smooth. I also sanded the block where they join, and I'm using an expansion chamber exhaust. I haven't been riding these bikes long, and I started out using the CNS carbs so I don't have a real good feel of what a stock engine/carb performs like, but I've noticed a couple things....
First... The engine idle speeds up as I roll down hill with the clutch disengaged. My logic was that the clutch wasn't fully disengaging and this was causing the increased idle. So I messed around with the clutch going back and forth with the acorn nut and I just can't get it set to where it both, engages and starts well, and cruises downhill without increased idling. The increase in idle is minor, but I have never noticed it on my 2 builds before this. Now I am wondering if the clutch isn't the reason but maybe it has something to do with the timing, or the expansion chamber keeping more fuel in the cylinder longer or something? I also noticed that after I slow down from high speed... the idle remains higher and then slowly drops down to baseline again. Maybe it's not the idle I am noticing, but the engine still turning and burning up fuel? I have no idea.
Even with no base gasket or head gasket, and having sanded the head/block... the longer than normal NGK spark plug is not hitting the piston.
My questions are:
1) the idling increase?
2) What do you guess I did to my timing/engine?
3) Is it detrimental? (Ie. should I replace the piston with a non-skirted one? or make any other changes? Will it shorten the life of the motor?)
4) What do you do when you are hauling *** downhill with the clutch disengaged and you get to the bottom of the hill where you want to give it gas again? When I engage the clutch going that fast it seems really hard on the engine and actually slows it down I think.
Thanks!