francisjohn
Active Member
What do you mean unchanged bottom end? The following needed to be doneUpdate: tried to take the bike on a solid ride and my mounting screws ejected themselves. And the vibrations from the engine caused my exhaust to come lose. Thankfully I noticed and the engine was fine. Are motorized bike supposed to vibrate in the higher rpms? I felt it all the way to the handlebars. Need a shorter exhaust and a way to suppress vibrations.
Overall though I think I’ve successfully created an ms460 build with a completely unchanged bottom end.
1) Bolt holes re-located by filling them with aluminum
2) Transfers filled up with JB weld
3) Deck the case to the neccasary amount needed. On a 38.0mm stroke, I decked it 2.5mm to obtain a 1mm squish.
Here are the photos of the MS440 I did. It's a freaking ripper.
Regarding vibrations, you will need to balance your crank. My crank was balanced to 56% and is smooth from 4500RPMs to 7,000RPMS. Some cranks stock are better balanced than others. By using a heavier top end (everything but the cylinder) you are increasing the reciprocating mass which decreases balance factor and makes it vibrate like crazy