250cc chinese moped

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1. Scooter Brake-In

   Different manufacturers recommend different break in procedures. For example most of our scooters manufacturers recommend the following:

   0-150km maximum speed 30km/hr
   151-300km maximum speed 40km/hr
   301-800km maximum speed 50km/hr
   801-1500km maximum speed 60km/hr
   Of course the speedometer is calibrated in mph and the odometer reads in miles, so some translation is needed. In round numbers these instructions correspond to:

   0-100 miles maximum speed 20 mph
   101-200 miles maximum speed 25 mph
   201-500 miles maximum speed 30 mph
   501-1000 miles maximum speed 40 mph
   What we recommend is to use the “ride it like you’ll ride it (but gently)” technique. That involves riding pretty gently for the first 25 miles (speed under 30 mph, revs under 4000 rpm), then changing the original Chinese engine and transmission oil. The original oil might be OK or it might be “cheap and nasty”. You have no real way of telling, so change it, then you’ll be sure. You may replace the original oils with Castrol GTX 10-30W in the engine and Castrol Hypoid 80/90 gear oil in the transmission. For the next 175 miles (25-200) you still should take it quite easy with no rapid acceleration, keeping the speed down below 40mph or 5000 rpm, then go ahead change the engine oil again. Since there is no real oil filter (the “filter” is just a mesh screen), changing the oil during the break-in period makes sense since it removes small metal particulates that the filter just won’t catch.

   During the break in period try to vary the engine speed as much as possible. This isn’t particularly easy with a CVT scooter since they tend to try to keep the revs pretty constant and change speed by changing the gear ratio. It is good to speed up and slow down and not ride at a constant throttle setting for long periods. Also avoid rapid starts and let the engine warm up for about a minute before moving off when you first start the scooter from cold to allow the oil to circulate. This is good advice even after the initial break-in period too.

   It’s probably not a good idea to use synthetic oil during the break in period. Good old dino (dinosaur!) oil is probably what you should use. Synthetic oil may be too slippery and not allow the parts (mainly the piston rings) to “bed in” properly. We suggest to stick with the manufacturer’s recommendation (typically 10-30W) until after the break in period of 500-1000 miles. Then you can switch to a synthetic blend if you want to. Amsoil make a synthetic oil which they claim is specially designed for scooters.

   Our break-in technique is to gradually increase speed over the next 300 miles (201-500) and at 500 miles do another oil change. After break-in, the engine oil should be changed at least every 1000 miles as part of normal routine maintenance.

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

2. Scooter Carburetor Adjustment

   If there’s any one component that’s more likely to go out of adjustment on your scooter, it’s the carburetor. If it does go out of adjustment lots of things can happen. It can make the scooter hard to start, it can make the scooter slow to accelerate, it can cause the scooter to idle badly and stall or it can make the scooter idle fast so that it’s trying to go all the time and needs the brake to hold it stationary. None of these things are good.

   What the carburetor does is regulate the amount of fuel and air which are supplied to the engine. To go faster you need more fuel and more air and they must be in the right proportion. The fuel also has to be atomized as much as possible (i.e. be supplied in tiny droplets). The carburetor controls all these functions and generally does it quite well. Without removing and disassembling the carburetor, there are only two adjustments you can make, but these should take care of most minor problems. The first is the adjustment of the idle speed.

   Above is a picture of a typical GY6 engine carburetor and the view is that from the right side of most engine configurations on 150cc Chinese scooters. There’s a small spring loaded screw which adjusts the idle speed. It’s right next to the throttle control which is connected to the twist grip on the right handlebar. On most 150cc scooters, idle speed should be around 1500rpm when the engine is fully warmed up. Don’t make adjustments when the engine is cold. Take a 5 or 10 minute ride first. When the engine is cold the automatic choke is in operation and that can change the idle speed. If you have a tachometer, setting the speed is easy. If you don’t, you want to set the speed to a low idle. Fast enough so that the engine doesn’t stumble or stall, but slow enough that the clutch doesn’t engage and try to move the scooter forward. On most scooters from 50cc to 250cc, this will be somewhere in the 1500-2000rpm region.

   The other adjustment you can make is to the low speed fuel/air (“mixture”) ratio. This is done on most scooters using a screw adjustment on the other side of the carburetor as shown below.

   This screw changes the air to fuel ratio at low speeds. It shouldn’t need much adjustment, but the way to do it is to turn the screw very slightly (1/8th turn) and see if the idle speed goes up or down. If it goes down, turn the screw back 1/8th turn to where it started, then 1/8 turn in the other direction and see if the idle speed goes up or down. If it goes down, turn it back to where you started since you didn’t need any adjustment! If the idle speed goes up, continue turning the screw in 1/8th turn steps until the idle speed is at a maximum. If it starts to go down, turn it back to get the maximum idle speed.

   You may need to go back to the idle speed screw to lower the idle speed if it’s now too fast. So the basic procedure is to set the fuel/air mixture to give you the fastest idle, then use the idle speed adjustment to set the speed to the lowest rpm that gives you smooth running.

   If the scooter idles well and runs fine at low speed, but has problems at high speed, the problem may lie inside the carburetor with the main jet. The fuel/air ratio at higher speeds is set by the jets inside the carburetor and to get at them the carburetor has to be removed and disassembled. This can be a tricky job as the parts are small and delicate. The good news is that these carburetors are quite cheap. You can get a new one for $60-$80, so if you can’t make your scooter run smoothly and you don’t like the idea of taking the carburetor apart, you can always replace it!

   Scooter Registration?

   If you’ve bough a fully assembled and tested scooter from a local dealer than they should take care of all the required registration. All you have to do is pay the dealer and your fully registered and inspected scooter should be delivered to you.

   However if you’ve bought a scooter through our website you’ll have some work to do. In most of the states you’ll need a manufacturer’s statement of origin (MSO), which the dealer should provide. This is a certificate from the scooter manufacturer which has the make, model and VIN (Vehicle Identification Number) on it and is proof that the scooter meets all applicable DOT and EPA standards for registration in the USA, and in particular for the state you are trying to register it in. You also need proof of insurance, the dealer invoice and a valid driver’s license. Then you simply drive to your local DMV office, wait in line for 20 minutes, get the forms, fill them out, wait in line for another 30 minutes and if all your documents are in order you get a title and your motorcycle plates (moped plates if your scooter is under 50cc).

   Then you have to take your scooter to an inspection station along with a yellow card which the DMV office provided, proof of insurance and a valid drivers license (with motorcycle endorsement if the scooter is over 50cc) and the inspection station will give you an inspection sticker good for 4 years. They may also check that your helmet meets local requirements (DOT certification etc).

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

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   Comment by Hung Bogda — 10/05/2011 @ 12:22 pm

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