I noticed that the transfer ports didn't match up when this motor was new, (I took it apart to check the crank for trueness and to measure the ring gap), before I ever installed it on my bike. I then put the motor back together and installed on the bike to see how the power was, then anything I did, I could see what kind of power increase I got. I used my Dremel tool, some diamond grinding bits, a carbide bit and a 1/4'' sanding drum.
Base gasket on cylinder...lines up well.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F017_zpsc70e8cfe.jpg&hash=16e876d82a6aebf4d0c6faada3ec38a5)
Base gasket on cases...ouch! Not a good match.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F005_zps02efa9ee.jpg&hash=10b16121ed931ae172c9277ad0a1e30f)
Used a awl to mark around the base gasket.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F016_zps80991c5a.jpg&hash=2518b93d4cd8c45899db0b5e464223ab)
Cases after grinding away up to my scratch lines.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F025_zpse8c849c4.jpg&hash=6fefa12a39807b006182c02412caa809)
Cases trial fitted back together...Oh, sooo much better!
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F024_zpsa0b739c5.jpg&hash=8bca1adb9b9afa12991a5f9ae58507ab)
This motor runs much smoother now, has a very noticeable power increase, accelerates way better and was a lot of fun to do.
Base gasket on cylinder...lines up well.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F017_zpsc70e8cfe.jpg&hash=16e876d82a6aebf4d0c6faada3ec38a5)
Base gasket on cases...ouch! Not a good match.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F005_zps02efa9ee.jpg&hash=10b16121ed931ae172c9277ad0a1e30f)
Used a awl to mark around the base gasket.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F016_zps80991c5a.jpg&hash=2518b93d4cd8c45899db0b5e464223ab)
Cases after grinding away up to my scratch lines.
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F025_zpse8c849c4.jpg&hash=6fefa12a39807b006182c02412caa809)
Cases trial fitted back together...Oh, sooo much better!
![](/proxy.php?image=http%3A%2F%2Fi480.photobucket.com%2Falbums%2Frr165%2FQuanah1980%2F024_zpsa0b739c5.jpg&hash=8bca1adb9b9afa12991a5f9ae58507ab)
This motor runs much smoother now, has a very noticeable power increase, accelerates way better and was a lot of fun to do.