Cimatti City Bike gas problem

I have a Cimatti City Bike, which has a Morini engine (I don't know they year; how can I find out?). My folks got it at a garage sale a long time ago, and used it a little bit. Then it sat in the basement for about ten years. Finally, I decided that I wanted to fix it up. So I cleaned out the carburator and the gas tank, which had been covered in oil gunk from the gas, and got it working. I used it on and off for about a year, then went off to my first year at college. I got back this summer, and started using it again. Or I tried, anyway.

I took it on a trip of about 5 miles, and then parked it for the night. The next day, it won't start. I've been trying to get it working again for a while now. After an hour or so of non-use, it will start up easy and run for about 20 seconds, then die. After that it won't start again, except for one day when I was pedaling it up and down the road trying to get it to start, and it would start every once in a while, run well for a few seconds and then die. Sometimes it would feel like it wasn't getting enough gas. Sometimes it would feel like was getting too much gas.

I've cleaned out the carburator a couple of times. I've mixed all new gas, and drained all of the old gas out of the system. I've checked for a spark. I've checked the gas flow from the tank. I've looked at the float, and there's nothing obviously wrong with it.

From what I know of the moped, it seems like the float is the thing that would cause a problem like this, but I don't know enough to be sure that its the problem.

Any tips that people could give me would be welcome.

Re: Cimatti City Bike gas problem

Chris Robertson /

Hi Tim:

1) Does your moped run properly with the gas cap off? Sometimes little breather holes in the gas cap can get blocked with crud and prevent the gas from draining out of the tank properly.

2) When you cleaned the carburetor did you blow compressed air through all the passages? Clean off the needle valve really well too.


Re: Cimatti City Bike gas problem

I haven't tried running the moped with the gas cap off, but I have checked the flow through the gas line where it attaches to the carburator, and it seems to be running fine.

I did use compressed air on the carb when I cleaned it. I think the only way my carb could get any cleaner would be to buy a new one.

clean and set the points?.. spark plug?

Use the "search" feature above to find my guide called "How To Fix Your Moped"... it has all the steps to follow to get your ped to run.

When you get to the "search" feature, type in the word... oxygen ... that will take you straight to it.

Re: clean and set the points?.. spark plug?


Re: Cimatti City Bike gas problem

Are you sure your moped has a Morini engine? I have never heard of a Cimatti without a Motori Minarelli. Believe me, I have one. Anyways, mine had some problems and I got a new spark plug and a new air filter and I cleaned out the carb. Now I runs like a champ. Good Luck. ~Kyle

Re: Cimatti City Bike gas problem

I to have a Cimatti city bike!! And I bought mine at a sale to. Sounds like not enough gas but to check just look at the fuel line. I had that problem and was air/vapour locked. soooooooo simple. Take off the line and flow the gas, to let spill a bit. then pit back on. May be that! Any idea how fast yours go? I can not get mine past 30 mph. I am working on getting an upgrade kit from 50cc-65-70cc. Steve's Moped in NewJersy has it coming soon! It will be about 190 bucks. But will give it at least 10-15 mph more!! Sound good? I can't wait. Put a fuel filter in your line as well. Can get one at a lawnmower shop/bike shop. easy to install. I am getting the signal light kit for mine from Steve's also. Expecting any day now! If you want to contact him you can do so at 1.201.384.7777

My name is Duane and can reach me at

Re: Cimatti City Bike gas problem

Problem solved, sort of. The mixture was too rich. This leads me to another question, though. Until now, I have been using some packing sponge inside the air box as an air filter. This is in addition to the metal screen thing that goes between the air box and the carburator. But these days, the moped will only run with that sponge taken out. Furthermore, I ordered a new air box, and it didn't have any filter in it (and there was no option of ordering such a filter). Now I'm wondering if this filter is actually supposed to be there at all, or if my dad just stuck it in when he was fixing the thing up. The moped is running great without the filter, but I'm worried about too much dust getting into the engine and messing things up.

So, if there is supposed to be a filter there, why isn't that sponge working (it breathes air ok)? If the carb is mixing too much gas in, and this is being corrected by having no air filter, then how can I decrease the amount of gas in the mixture?

To answer Duane: On level ground, my bike will go 30, no problem. It also says "Max speed 30mph" on the tire.

Re: Cimatti City Bike gas problem

whoa, hey. wish I had read this reply earlier. I wouldn't have had to wait until the air filter fell off to figure out that it was the problem. Also, you're right about the engine. Sometime between going down and looking at the engine, and reading Motori, and going up here and typing it in, it changed into Morini.

Re: Cimatti City Bike gas problem

Hi,Tim! You can fashion an air filter into your air box,but it has to be really thin material `cause most peds get restricted too much with regular foam.You have to use a foam that will resist gas without deteriorating.The material on room air conditioners is perfect,but i'm not sure how resistant it is to gas.I would only worry about a pre filter if I had some dirt or gravel roads or constuction zones to travel,though.If you do this you need a backing grid to clip the material into(1/4" X 1/4" wire mesh is perfect).There are filters you might adapt,but the main thing is not to turn them where water and debris are thrown toward the intake holes,and watch out for causing too much restriction,cause it robs your power and mileage and clogs your plug and muffler.I saw where one guy put a `K&N'racing filter on his ped,but I have no idea how to do it other than to `MacGiver' it.BYE!

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