Trouble Shooter Guide for NO-CRANK Chinese Engines
Chinese ATV Trouble Shooting
How to Test Starter System - No Crank
When troubleshooting a Chinese ATV, Dirt Bike, Go Kart for no cranking by the electric starter, there are a couple of easy steps to take. This troubleshooter article is about how we test the Chinese ATV starter systems when arriving in our shop.
Before we get started - our number 1 technical support assistance phone call for newly delivered Chinese ATVs is a no crank, no start, no lights come on situation. New Chinese ATVs, Dirt Bikes and Go Karts have a safety switch that is usually tied into the braking system. Such as a brake light switch operated by pulling in the handlebar mounted brake lever or depressing the foot brake pedal. The rear brake light comes on while the key is on and that tells you that the safety switch is working. Its also referred to as a starter lockout switch. Your new ATV will crank once you operate the brake lever or pedal. I had a 50cc moped scooter that would not start with the side kickstand down because of a safety switch .
Customers will contact us describing a clicking or buzzing noise coming from the starter relay or starter solenoid while trying to start the ATV. We use an inexpensive volt meter to test voltage at the battery. MUST HAVE 12 VOLTS or more on a fully charged battery. More starters or relays are replaced when the problem actually was a low voltage or defective battery. Easy fix - charge the battery or replace the battery.
There is 3 major electrical components in the starting system of the Chinese ATVs.
First is a good HOT 12 Volt Battery. Just because the battery is new or ?? doesnt mean battery is at a full 12 volts. Must test or use a good known battery from another ATV. Side note here - It is a risky to jump start an ATV using a car or truck system - much higher amperages and if you do have an easy problem - could become major problem once the high amperage auto system starts frying wires and melting other delicate electronic devices on your kids ATV machine.
Number two is the starter relay or solenoid switch. Easily identified by the heavy red wire coming from the ATV battery to the starter relay solenoid switch. There is two larger terminals or posts on this switch. The second post has a heavy wire attached and runs down to your electric starter motor. This solenoid is activated by depressing the handlebar starter button switch.
Final third component is the electric starter motor itself. Side note - when replacing the starter motor on a Chinese engine under 125cc, remove the left dry (no oil) engine cover or stator magneto cover. You will see a sprocket on the end of the starter motor that hooks to a starter chain. To properly install a new starter you must remove this left stator cover to access the starter chain and make sure starter chain is properly engaged on the new starter. Many mechanics new at this will remove the armature portion of the starter not knowing there is a sprocket on the end of the starter motor. We receive many pictures by email of half starters or armature portion requesting that we match one up for them. A complete starter comes with a sprocket on the end that attaches to the starter chain in the left side cover. This is only for the 50cc, 70cc, 90cc, 100cc, 110cc and 125cc Chinese engines. There are other 150cc 250cc starters that are just a splined shaft on the end - that style does not require cover removal.
Our shop will check battery voltage first or install a new tested battery. We will then locate the starter relay solenoid switch and get access to the two larger posts or terminals with the heavier wires attached. We will use an open ended wrench and touch the two legs of the wrench to both larger terminals simultaneously. We are by passing the handlebar starter switch and making 12 volts of electrical current run from the GOOD battery direct to the electric starter motor. IF we have good engine cranking by jumping these larger posts together - this means we have a defective starter relay solenoid switch or handlebar push button starter switch is defective or we have a starter lockout safety switch problem.
IF we still do not get starter motor cranking, we check the heavy wires including the battery ground cable for good connections or corrosion. IF no problems there then we will remove the starter for testing and or replacement with a new starter. Starter motors can be bench tested by holding the metal case of the starter to negative post on a car battery - and using a heavy wire from the starters wire attachment point and touching that heavy wire to the positve terminal on the car battery - a good starter will spin in your hand. Listen for abnormal noise or dragging, erratic spinning of the starter motor.
OK, so my ATV I can hear the starter spinning and no engine crank - remove the left cover and spin the starter motor again - watch for broken starter chain - or you may have a defective one way starter clutch that is mounted behind the magneto flywheel. A different subject for another Chinese ATV Trouble Shooter article.
Note: We are referring to the starters in this article that are used on 125cc and under Chinese Engines - See our Chinese Engine section for full blown pictures of the Chinese engines we refer to. Also this engine could be a bottom mount starter engine or a top mount starter engine - starter replacement is basically the same. Again, check our Chinese Engine section for pictures of top and bottom mount styles of Chinese Engines.