06 August 2012

New Jug

Since I had an oil leak on my scooter I came up with a few options:
  • Ignore it and deal with the dripping and mess.
  • Replace the cylinder base gasket. Requires pulling the engine. Cost about $10.
  • Replace the entire cylinder and piston with an overbore. Also gets the gaskets and requires pulling the engine. Cost about $100.
I decided it would be fun to do a big block kit since I dont like the messy oil and I have to pull the engine either way and it's not very spendy. Now I can pull or replace the engine from my scooter in under an hour. It took me maybe 2 hours to replace the jug. It was mostly fun. I made timelapse videos of much of the process.
Since I had the engine out and I was cleaning everything, my rear brake had gotten oil on it and was not effective anymore. I had new pads for it so I really cleaned up the caliper and painted it red. Looks great and took me forever to bleed the air out. I ended up getting brake fluid everywhere.
The original piston/jug had a bunch of carbon buildup. I think this is normal though. I thought it was interesting that the original crosshatching was visible on the old cylinder wall even after 9,000 miles. Not sure if that's normal?
The other interesting thing I discovered was the cylinder outer diameters. The old one had a diameter of 60.5mm. The new one has an OD of 62mm. When I placed the new jug on the engine without a piston or alignment pins it had lots of wiggle room in the case. I forgot to measure the case inner diameter, and really wish I had. Now I wonder if I could have put in a 63mm jug with its 65mm OD and not needed to bore the case.

Unfortunately I still have the same oil leak. Now I think it must be the head. I don't want to replace it but I'm pretty unhappy about the leak.