loncin 250cc air cooled 4 stroke wont start

[matt8888]

g'day I've got a loncin 250cc air cooled 4 stroke, my nephew (3) thought it would be a good idea to fill it up with water by sticking the hose down the exaust. ive drained the engine cleaned the carbi and air box changed oil and spark plug basically covered the basics and still cant get it going its throwing a spark. does anyone have any idea what I should try next?

 

[rotn50]

Have you tried turning it over with the plug out to see if there is excess water in the combustion chamber, normally you would get the water enter the head assy also and that keeps letting some water in as you try to start it. if so even if the plug is wet with water it will be hard to start and the plug needs pulling out and drying each time before starting again, Start ya bastard or aero start is also a good thing to have on hand to try starting it.

 

[Blender]

try the aerostart, and if it fires, but dies not long after, take the air box off, and place your hand over the mouth of the carb. (where the airbox used to go) and kick it over lightly. it'll draw any small blockages and make starting a little easier.

Also, pull your carb and give it a good clean with compressed air and carby cleaner.

 

[matt8888]

yeah that's exactly what its doing fires on aerostart but dies fairly quickly afterwards ill give it another go during the week and let ya know how it goes.

cheers guys

 

[Blender]

^^thats exactly what my 125 did. i know its a completely different engine and all, but the principal is pretty much the same. i found by leaning the mixture screw out a bit, it was fine. have you checked your plug's electrode colour? it should be a coffee color. if your plu'g colour is white, it means ur too lean, not enough fuel going into the combustion chamber.
if your plug's electrode is black/sooty that means too much fuel going into the combustion chamber.

its always best to run a tad rich, it ensures your engine stays cooler-ish, as opposed to a lean mixture, which would cause ur engine to run hot.

Too lean your mixture screw, it is the opposite of a tap. so to get a richer mixture (add more fuel) you turn your mixture screw in. to lean it off, screw it out (to lessen the amount of fuel). Good luck

 

[my67xr]

i would be pulling the carby off, and giving it a thorough clean out,
remove Main and Pilot jets, Needle jet, mixture screw/spring/washer seal, the float and needle and seat.
clean inside all the ports on the air filter side, and blow through them with compressed air, checking that you can feel it coming out under the carby base through the ports.
at the bottom of the thread where the Pilot jet screws into, there is a tiny hole that goes through into the carbys' main bore.
that needs to be open, to supply fuel for idle > 1/4 throttle
if you cant blip rev it without hesitationm then your Pilot/idle mixture circuit has a blockage/restriction somewhere