250cc gas motor bikes

2 Comments »

1. Scooter Assembly

   If you are located in CA, and you are picking up from our retail store, you can choose to have your scooter fully assembled and inspected by our trained mechanics. If you order the scooter through our website, you’ll have some work to do. It will arrive in a steel cage inside a cardboard box.

   First remove the cardboard box. This is the easy part! Then you’ll need to take apart the steel cage by removing all the nuts and bolts holding it together. At some point in the process you may need a second person to help you by holding the scooter upright while you remove the last few bolts and possibly the bailing wire used to secure the scooter to the base of the cage. Most of the scooters we carry already have both wheels attached, you can roll it out of the case and set it on the center stand.

   Now you can look for “assembly instructions”, which with the average Chinese scooter will be one sheet of paper which says something like “attach the rear view mirrors, install the battery, etc.”. You may have to use some ingenuity to figure out how to do all this, but it shouldn’t be beyond the capabilities of any amateur home mechanic. It may help if you have a decent socket set, screwdriver set and set of metric wrenches since the supplied “tool kit” usually leaves much to be desired.

   Batteries are typically shipped “dry” with the acid in a separate container. You have to add the acid to the battery and leave it for 30 minutes of so before using it. After this it shouldn’t need to be charged to start the scooter.

   Once you have all the parts attached (and that will include at least mirrors, seat, rear carrier, battery and floor mats), and you’ve waited about 30 minutes after adding acid to the battery, you’ll be ready to start the scooter.

   If you just put fuel in the tank, you may have to crank it quite a few times before it starts since the fuel has to get to the carburetor and fill the float chamber before gas gets to the engine. You can prime the carburetor by disconnecting the fuel hose from the vacuum valve and connecting it directly to a small funnel and adding a little gas, then reconnecting the fuel line to the valve and adding fuel to the tank. However if you don’t know what you’re doing, just try to follow whatever instruction came with the scooter. Use premium gas. Most scooters seem to be setup to run on 91 octane fuel.

   The final point of assembly is to check everything. Check the tire pressures, check that every bolt and nut you can see is tight, especially the ones holding the exhaust and muffler – and the wheels! Look around for lose wires or rubber hoses that don’t seem to be attached to anything.

   Comment by Anonymous — 05/12/2010 @ 3:15 pm

2. If you are getting a spark and you are getting gas to the carburetor and the engine is turning over on the starter OK, it’s possible that the electrically operated automatic choke has failed. It’s supposed to operate when the engine is cold, but if it’s stuck or burned out, the mixture will be weak and the scooter probably won’t start. The automatic choke is usually a black cylindrical object attached to the carburetor with a couple of wires coming out of it as shown on the left. It’s the only electrical powered component attached to the carburetor, so it’s usually not hard to spot. If you have a voltmeter you can measure the resistance across the leads of the choke. It should be somewhere in the region of around 10 or 20 ohms. If it’s an open circuit, it’s burned out and will need to be replaced. If it seems to be OK it may be stuck, or the wiring to it may have a problem. Check to see that it’s getting voltage.

   It’s also possible that there is a problem with the carburetor and if so you may need to remove it and clean it out. If the scooter has been sitting for a few months with gas in the carburetor, the gas may have evaporated and left a sticky “gum” behind that will prevent the carburetor from working properly and which must be removed.

   If the automatic choke is OK, the starter cranks the engine, there’s gas and there’s a spark then there may be an engine problem. You need to check the cylinder compression. You need a compression tester to do this. It screws in instead of the spark plug and measures cylinder pressure. When you crank the engine you should see a reading of around 150 psi or more. If it’s 100 psi or less there’s likely and engine problem (bad valve, bad piston, failed piston rings) which will need the engine taken apart to find.

   Comment by my way — 05/12/2010 @ 3:15 pm

RSS feed for comments on this post. TrackBack URL

Leave a comment