Saturday, July 25, 2009
Moto 4 Resuscitation
Well, I had my doubts, but alas the "little motor" is a trooper. After some extensive cleaning of the ports and head, and the installation of a new intake valve, it's running again. (If you lived in my neighborhood you would know by the test runs up and down the street.)
Working on a small machine can be frustrating. Sometimes it's like building a model. It requires plenty of light and some extra tools for handling the miniature parts. The head bolts require a whopping 8lbs of torque. All in all it went together pretty quick. As usual, having an OEM repair manual is a big help. With the valves and cam chain carefully adjusted, it purrs like a fat kitten.
Next some new brakes may be in order.
Working on a small machine can be frustrating. Sometimes it's like building a model. It requires plenty of light and some extra tools for handling the miniature parts. The head bolts require a whopping 8lbs of torque. All in all it went together pretty quick. As usual, having an OEM repair manual is a big help. With the valves and cam chain carefully adjusted, it purrs like a fat kitten.
Next some new brakes may be in order.
Friday, July 17, 2009
Moto 4 Revival Set Back
After a particularly stressful day, I decided I would take OBB for a ride on what he calls the "little motor." So I rolled the Moto 4 out of the garage and prepared to start it, which usually means giving it a little push in the driveway (the battery needs to be replaced.)
After a few feet, I stopped in shock. The motor, when it started to turn over, sounded like one of those mechanical monkeys clapping his cymbals together. Clack-clack-clack-clack. My heart sank. I knew it was catastrophic. Not willing to face the demons, I rolled it back in the garage and closed the door. OBB's questions followed me back into the house.
A few days later, I decided to have a closer look. The noise seamed to occur on every stroke, and the compression was non-existent... could only be one thing... so I unbolted the head to see which valve it was.
After a few feet, I stopped in shock. The motor, when it started to turn over, sounded like one of those mechanical monkeys clapping his cymbals together. Clack-clack-clack-clack. My heart sank. I knew it was catastrophic. Not willing to face the demons, I rolled it back in the garage and closed the door. OBB's questions followed me back into the house.
A few days later, I decided to have a closer look. The noise seamed to occur on every stroke, and the compression was non-existent... could only be one thing... so I unbolted the head to see which valve it was.
Intake? Exhaust? Any guesses? If you guessed intake, you're right. Unfortunately, the varnish that the previous owner allowed to play havoc in the carburetor seems to have had its way with the intake valve as well. The noise was the rocker arm tapping on an open valve.
I can't tell if it's bent, or just sticking from all the varnishy gunk. I suspect it's both. The piston and jug look fine, so I'll see if I can get the valves working again. We'll see. I'd hate to have to take Ole Yeller out to the shed.
