Making a scooter run.
I have always had problems getting my old antique scooters to start and run. Most of them are about 50 years old and they have weak ignition and primative carburetors. My 1947 Cushman has a six volt system with a magneto ignition and the compression ratio is only 6 to 1. But if everything is right, a scooter that old will run just fine.
Not being a mechanic, I am lucky to have one or two running at any given time, but I am learning a few tricks. I had an epidemic of stuck float valves in carburetors. It only takes a grain-of-sand size glop of goop to stick that little valve and then it either floods and drips gas causing it to run rich and foul the plug, or no gas gets in there at all.
So where was the goop coming from? Well, the gas tank, of course. Cushman put a fine screen in the top of the settling bowl to strain out goop, but micro glops pass through, consolidate and gum up the float valve. Old gas left in the tank for a few months makes its own goop.
The solution is inline filters. I use a small plastic filter made for lawn mower engines and as soon as I put one on a scooter, it starts and runs. I won't say the problem is completely solved, but this has been a giant step.
One thing I will have to remember is to remove the inline filter from a scooter that I enter in a show. Non-original parts cost points.
I even put one of those dandy little filters on my 1966 Benelli, which is a lightweight, two-cycle street bike and it goes better than it ever did. I sure wish I could figure out that silly 4-speed foot shift. It's on the left side and I'm right footed.
Howard
Not being a mechanic, I am lucky to have one or two running at any given time, but I am learning a few tricks. I had an epidemic of stuck float valves in carburetors. It only takes a grain-of-sand size glop of goop to stick that little valve and then it either floods and drips gas causing it to run rich and foul the plug, or no gas gets in there at all.
So where was the goop coming from? Well, the gas tank, of course. Cushman put a fine screen in the top of the settling bowl to strain out goop, but micro glops pass through, consolidate and gum up the float valve. Old gas left in the tank for a few months makes its own goop.
The solution is inline filters. I use a small plastic filter made for lawn mower engines and as soon as I put one on a scooter, it starts and runs. I won't say the problem is completely solved, but this has been a giant step.
One thing I will have to remember is to remove the inline filter from a scooter that I enter in a show. Non-original parts cost points.
I even put one of those dandy little filters on my 1966 Benelli, which is a lightweight, two-cycle street bike and it goes better than it ever did. I sure wish I could figure out that silly 4-speed foot shift. It's on the left side and I'm right footed.
Howard
posted by Howard at
7:54 PM
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