Part V

Mechanical Meditations

It’s been a while since I’ve posted; the MB5 project was put on the back burner while I flew to my hometown on Cape Cod, Massachusetts, to marry my girlfriend of 9 years. Now I’m back in LA, and with the sun just rising in the sky, the wife still sound asleep, and a fresh cup of coffee at the ready, I’m eager to pick up where I left off.

Wife had flown East early and left me home alone for a time, and during that week I lingered at the kitchen table late into the night tinkering with the engine and any other components I had parts for. I got quite a bit done. The forks have been overhauled and installed, the swingarm, shocks, and center stand bolted up, I rebuilt the master cylinder, and reassembled the engine with a new balance shaft bearing and 70cc big bore kit. Whooyeah!

I phoned Rick Perkins at Perk LLC to inquire about engine gaskets and a new top-end. Rick and his brother peddle parts for a variety of mopeds, but MB5s are their specialty, and Rick had some great advice for my build. He had the gaskets in stock (none of the 5 dealerships I called did, they’ve been discontinued), but he was sold out of the various big bore kits and a special order from Europe would take weeks.

Being the impatient type – and eager to get the engine assembled before I took off for 2 weeks – I hit the internet for an alternative. is another major parts supplier that I somehow overlooked during my initial online searches, and they had several kits in stock. I went with the 2-ring 70cc Malossi kit from Italy; the double-ring setup should provide better low-rpm performance and extended service life compared to the other racing-based single-ring kits. The parts shipped from San Francisco so it only took a day to get here. The kit came with a several base and head gaskets of varying thickness, and since there were no instructions (that I could read, anyway) I had to mock up the top end several times to figure out which gasket combination yielded the best port timing and squish band depth. With that sorted out I put a decent shine on the combustion chamber and exhaust port and torqued everything down. The engine is complete!

Next up? Sealing the tank so the rust doesn't return, reinstalling the engine, and mounting tires on my sweet 18-inch Comstar mags. Once that's done I figure the parts will start flying out of the boxes and finding their place on the chassis. And I figure that now that the wife is back the project will brobably have to be moved outdoors again, but she hasn't said anything yet!

Resources: 70cc kit

Perk LLC -Case gaskets and technical advice. Supplier of hard-to-find moped parts. (317) 371-8530

Rusteco-Rust removal treatment for the MB5's gas tank. (800) 787-8326

Haynes Manuals
-Invaluable technical information and diagrams.
(800) 242-4637

Huntington Beach Honda
-Various OE parts such as gaskets, grommets, and seals.
(714) 842-5533

MB5 Project engine
MB5 Project engineMotorcyclist
MB5 project frame
Working with the frame.Motorcyclist
Ari Henning
Ari working to fit together the pieces.Motorcyclist