250cc motor bike

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1. 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!

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

2. Each MSO Title certificate will be accompanied by a Bill of Sale and Invoice for registration purposes. If your state requires your MSO to be notarized, please indicate on your MSO request form. There is a $25.00 fee for each notary. We offer overnight service for an additional $55.00. Please note: overnight service only guarantees we mail your documents via overnight service. We do not guarantee your MSO will be prepared and processed overnight. There is $20.00 fee for each replacement MSO.

   Once you receive these documents, you need to take them with your scooter or motorcycle to your local DMV (Department of Motor Vehicle). They will inspect the bike and compare the VIN (Vehicle Identification Number) on the paperwork to the one on the scooter. They will inspect the vehicle as well.

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

3. Scooter Oil Change

   What we are going to describe is how to change the engine and transmission oil in a 150cc Chinese scooter with a 4 stroke engine. The procedure should be pretty similar on 50cc and 250cc models with 4 stroke engines. 2 stroke engines mix gas and oil and so have no engine oil to be changed.

   We’d recommend changing the engine oil at least every 1000 miles, and the transmission oil at least every 2000 miles. Regular oil changes are the easiest and cheapest way to maximize the life of your engine. Scooters take so little oil that it should cost less than $5 to do and once you know how to do it, it should take you more than 10-15 minutes. It’s time and money well spent.

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

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   Comment by Joi Schuchard — 01/31/2012 @ 5:54 pm

6. Climbing is differentiated from hiking by the ‘up and over’ mind set that climbers often

   Comment by learn — 02/05/2012 @ 6:34 am

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