Underblog Rides Again

Disappointment is Best Served Cold

Alas, the perfectly running 275 was too good to be true for long. A week ago Friday, Mrs. Blog and I took her to the Thai place around the corner, where she dripped fuel and refused to start. And refused to start. I pushed and pushed. We walked home to get the car. Armed with the BMW toolkit, I could check for spark and clean the plug and so forth. Really, one can do just about anything with one of those. I ended up pushing the Letta home a mile or so. The incident got Mrs. Blog and I really talking about the utility of a pickup truck.

I popped off the bodywork and got the battery on the charger, while I checked the float, which given the fuel drip seemed the most likely culprit. Scooters are brilliantly engineered to hide all the workings underneath bodywork, but they can place things in bloody unituitive places. At any rate, cleaning the carb out did not do the trick.

Over the next week, I checked the timing, which on Maicolettas is a rather arcane ritual, full of marks on the fanwheel cowl and multiple sets of points. The gaps were large, but not so large that the bike would not run. Evidently, close is good enough on these machines. And so I turned to the carburettor. (Spark properly timed, fuel properly mixed, and compression sufficient to make an explosion of the other two are the three elements of an internal combustion engine). After getting no love from rebuilding the carb (how nice to have compressed air around -- finally!), I swapped in Sil's carb body, the jets being easy enough to visually inspect.

Along the way, I had the presence of mind to check the fuel tap. It was totally blocked in all positions. I put the Lambretta tap (a new one) on, it too was blocked. What the? I dismantled the Lambretta tap and put its rubber seal in the right place and put it back together. Finally, the carb would get some fuel. This may have been the problem all along. However, the best I can manage is an initial "pop" and then nothing.

At the advice of the Maicoletta Board, I swap out the "black box" with the black box on Sil. For the uninitiated, many motorcycles have black boxes that control ignition and timing. I notice that the connections are kind of cruddy and that several of the wires appear to be losing their insulation. But lo and behold with the "new" black box the Letta fires up! I shut it down, put the bodywork on and it starts again! It is back. I decide to ride over the bridge to Minneapolis to show it off to S., who had so much trouble with the new old Lambretta Ld she bought on eBay.

I never made it. Approaching the bridge from the Mississippi River Road, the Letta lost power and died. It was a pleasant enough push home, as far as pushes home go (and I have had a few). A burnt-electrical smell emerged from underneath the bodywork. The battery was dead. Both the battery and the black box were hot to the touch. With the body work removed, it became apparent that the smell was coming from the black box.

There are now two possibilities:

1. Sil's black box is faulty: An inability to recharge may be why the machine was parked after only a few miles, before I even took possession of her.
2. SG has a short which kills black boxes: This is a scary proposition indeed, since it means that I risk smoking another black box by putting SG's original box back in her.

On the bright side, I was finally able to remove the last piece of Sil's disintegrated clutch basket by using two C-clamps and sawed-up length of square channel. To think it only took me several years to figure it out! Still, it is nice to have a shop where one can make the necessary tools. This means that if I can figure out how it all goes back together, Sil may be running again by the end of summer. . .

Posted by webs0080 at July 6, 2004 6:26 AM