Wild child 911

Hi Piercelt. With spark plug removed from head and inserted into the plug lead, earth against motor and crank motor. Check for spark at spark plug gap. This will tell you if it is spark or fuel.

HI. There is also a bleeding screw at the water pump. You definitely have air in the system if the level drops in radiator as this should not happen. Try bleeding at the 3 points as in previous replies.

I have found problem and would like to share. Fuel injector became sticky. Replaced injector and problem solved.

Check exhaust for blockages firstly, then ensure carburetor intake manifold is not cracked or loose. To much air will also do this.

I agree that system must be bled for air. Start at motor at the thermostat, there is a bleeding screw. Motor must be running. Then move to radiator. Remove cap and at the back of radiator on towards the top on passenger side, there is a bleeding bolt. Remove bolt and have someone assist you filling radiator until water starts running out. Replace bolt and top up radiator. Install radiator cap. Remove plug on sensor and insert bridge piece wire. Fan should then run. If fan does not run, replace sensor. You can also test heat gauge at the thermostat by installing bridge piece. There are two sensors, do the one after the thermostat.

I have the same problem with my 450 sector. What i find works is to give a quick blip on throttle and as revs drop engage the gear. Don't rev to high as gears could be damaged. Do the same if you need to remove from gear to neutral position.

I have a 2018 model Hisun 450 EFI UTV. I have done over 6000 trouble free kilometers. About 4 weeks ago i felt that utv was not performing like it should. Done a compression test and found to be low. Replaced rings as they were worn. I drive in a very dusty environment. The problem of low power is still there. I have checked cam timing, valve clearances, compression up to 9.5 bar, done leak down test and valves are seating, stripped and cleaned fuel pump, removed and cleaned throttle body, checked for leaks on throttle body manifold, replaced spark plug, tested stator coil, tested hv coil, checked all electrical connections, checked injector. UTV starts easily and idles for 5 seconds and cuts out. When utv starts, it will rev up the first time and then start to miss as if it goes into a limp mode. If i lift my foot of the accelerator utv will idle for 2 seconds and then die. It starts immediately again. Would the air flow/ air pressure sensor or exhaust gas(lambda) sensor cause this. I cannot test them as dont know the correct values. Any suggestions will be highly appreciated.