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Zappa · 06-06-2020, 01:18 PM

I think I may have a similar problem with my 02" Zuma and I'm suspecting the reeds.
Here's a little history; I bought it 2 years ago from the original owner, with only had 4000 miles on it. He's an older guy who only used it to buzz around the campgrounds, so he never took it on the streets. Later he bought a golf cart and stopped using the scooter. I bought it from him and right away I replaced the battery and the dry rotted OEM tires.
It ran good, but it topped out at 37 mph. I needed more power and speed to keep up with traffic because the roads around here are mostly posted 35-50 mph. Usually people are driving faster than that and I don't want to get run over.
Last year I got an NCY 47mm kit (70cc ?) which came with a pipe, jet set and clutch/variator. It took a lot of trial & error to get the jetting right to where it made good power without bogging down in the mid-range. I check the plug often and it's a nice tan color.
I usually only make short trips around town, 3-4 miles, then stop at the market or wherever for a few minutes, it ran fine and hot restarts were not a problem.
Anyway, I took it for a longer ride a few days ago, it ran good, I got it up to 50 (I read the speed on a GPS) and was cruising around 45 or so, when it suddenly shut off. I coasted to the side of the road and tried to restart it. It cranked normally, but didn't fire. I then pulled the plug, looked good, nice tan color, then checked for spark, which looked OK. I stuck my spare plug in anyway, that also looked to have good spark. I had plenty of gas, and there was gas in the carb, I could smell it, and after trying to crank for awhile, the plug would appear to be a little wet with gas.
Luckily I was only two miles from home, so I walked back, hooked up my trailer and went to retrieve the Zuma.
I just parked it until the next day when I had time and daylight to mess with it. I stuck my finger in the plug hole and cranked it, compression felt good. Checked for spark again, that looked good too. Put a new plug in, cranked, by no start. I put my hand over the exhaust pipe outlet, and I felt flow as I cranked it. Next I pulled the air filter (aftermarket, not stock air box) put my hand over the carb inlet and cranked again. I felt vacuum sucking, but I also felt it spitting gas back onto the palm of my hand. This is why I suspect the reed valves.
Does it sound like I'm on the right track here ???
I just ordered a new reed block, so when I get it, I'll pop that in and see if that's the cure.
Assuming I'm right and it's the reeds, is it normal for the engine to just outright quit when a reed fails ?
There was no loss of power, sputtering or strange noises before it quit running, it was instantaneous, like I had turned off the key.
One more thing, when it quit, it felt like it was pretty hot and I did get a little burning smell. I've heard the term "soft seize" a few times, but never got a clear explanation of what that is, can someone please elaborate ?

06-06-2020, 01:18 PM	#4
Zappa Join Date: Apr 2019 Location: Live Free or Die Posts: 8	I think I may have a similar problem with my 02" Zuma and I'm suspecting the reeds. Here's a little history; I bought it 2 years ago from the original owner, with only had 4000 miles on it. He's an older guy who only used it to buzz around the campgrounds, so he never took it on the streets. Later he bought a golf cart and stopped using the scooter. I bought it from him and right away I replaced the battery and the dry rotted OEM tires. It ran good, but it topped out at 37 mph. I needed more power and speed to keep up with traffic because the roads around here are mostly posted 35-50 mph. Usually people are driving faster than that and I don't want to get run over. Last year I got an NCY 47mm kit (70cc ?) which came with a pipe, jet set and clutch/variator. It took a lot of trial & error to get the jetting right to where it made good power without bogging down in the mid-range. I check the plug often and it's a nice tan color. I usually only make short trips around town, 3-4 miles, then stop at the market or wherever for a few minutes, it ran fine and hot restarts were not a problem. Anyway, I took it for a longer ride a few days ago, it ran good, I got it up to 50 (I read the speed on a GPS) and was cruising around 45 or so, when it suddenly shut off. I coasted to the side of the road and tried to restart it. It cranked normally, but didn't fire. I then pulled the plug, looked good, nice tan color, then checked for spark, which looked OK. I stuck my spare plug in anyway, that also looked to have good spark. I had plenty of gas, and there was gas in the carb, I could smell it, and after trying to crank for awhile, the plug would appear to be a little wet with gas. Luckily I was only two miles from home, so I walked back, hooked up my trailer and went to retrieve the Zuma. I just parked it until the next day when I had time and daylight to mess with it. I stuck my finger in the plug hole and cranked it, compression felt good. Checked for spark again, that looked good too. Put a new plug in, cranked, by no start. I put my hand over the exhaust pipe outlet, and I felt flow as I cranked it. Next I pulled the air filter (aftermarket, not stock air box) put my hand over the carb inlet and cranked again. I felt vacuum sucking, but I also felt it spitting gas back onto the palm of my hand. This is why I suspect the reed valves. Does it sound like I'm on the right track here ??? I just ordered a new reed block, so when I get it, I'll pop that in and see if that's the cure. Assuming I'm right and it's the reeds, is it normal for the engine to just outright quit when a reed fails ? There was no loss of power, sputtering or strange noises before it quit running, it was instantaneous, like I had turned off the key. One more thing, when it quit, it felt like it was pretty hot and I did get a little burning smell. I've heard the term "soft seize" a few times, but never got a clear explanation of what that is, can someone please elaborate ?
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