I have a 2003 Abuzzi. I bought it new in July 03. It has 3000 kilometers on it. For the past 3 months the engine’s performance has been slowly degrading. It first started with longer warm-up time. Then poor performance after starting even after it was warmed up (incidentally warm up is no big deal, I live in Hawaii). Now it’s at the point where the performance is bad all the time.
Today I called the dealer I bought it from and told him about sputtering, hesitation, low power and over all poor performance. Believe it or not he said the problem was most likely the transmission drive system. Yea no shit, the frigan drive system. Said the constant speed V-belt drive system has a spring in it and after Heavy City driving the spring weakens and causes poor performance due to premature clutch engagement. He had about 6 different springs of this type hanging on the wall. He said they were for different models and some had different tensions (for performance).
I'm no moped expert but I have been playing around with 2 and 4 stroke engines all my life and for the life of me I just cant buy the drive train being the cause of my ped's problem. Oh well I bought a spark plug from him any way. Slowly puttered across the street into a parking lot and popped it in. The plug made very little improvement in performance. I drove it straight home and thought about first steps in solving the problem.
The way it ran on the last leg home, gas starvation came to my mind. Drove it up on my concrete carport and started removing the plastic panels around the motor. Gas line that’s it let me pull this rubber tubing just below the gas filter off. Good flow, that’s not it. How about following it through this air manifold and on to the carburetor. Yanked it out, no; good flow there to. How about the bowl, maybe the float it stuck in a high position and is causing gas starvation. Nope, bowl was full and the float mechanism felt smooth. OK Ill spray some gum-out into the crab fuel in-let port and any other hole I can find. Well I did something so I might as well stick the carb back into the rubber cylinder intake and fire it up without putting the air intake box back on.
I started it up and opened it up with the back wheel off the ground. It revved up stronger than usual but totally died out and stalled. This is weird; it never staled out before. It now has a new symptom; it revs fast and strong but stales out every time. I noticed an Electro mechanical solenoid type valve built into the carburetor. I disconnected the wire and removed the device. It was a solenoid type needle valve that stuck way down into the beginning of the carburetor near the bowl. I started the engine up without it and gave it a rev test. The engine still died out but when I put my finger over the opening in the carburetor from the removed valve it revved high without staling. But if I keep it covered with the engine revving down to idle, it would stall.
I tested the solenoid valve and got 29 ohms. Put a voltmeter on the connector that plugged into the valve and started the engine. The volt meatier slowly peaked to 5 volts at full rev. The valve did not respond to 12 volts. I called the dealer up and he said the valve is an automatic choke. And responds to heat. I asked him if the ohm resistance value decreases when heat is applied. He said he’s not exactly sure how it works. I heated it up with a propane torch and then tested the ohms. No change. I removed the needle and put the valve mechanism back on the carburetor. Tested the moped around block and it seemed to run smother and more consistently.
Unfortunately after I put the air intake box back in, the engine’s performance problem returned. If someone can bear though this post and suggest something before I turn black with grease, I would greatly appreciate it.