Hi, bike was running two weeks ago......now no go. Engine turns over, chcked plugs, found one not sparking.Replaced all 4 plugs, good sark on all 4. Fuel is getting through but just wont fire. Anyone got any ideas, thanks, Steve

when you say fuel is getting in how much? are the plugs wet? go buy a can of easy start spray the intake and crank her over if she fires then its a fuel problem if she dont then its spark, had a similar problem with my mito625 the problem was there was corrosion under the coil mount and i wasnt getting a good enough earth might be worth checking.

kaighn80 wrote:when you say fuel is getting in how much? are the plugs wet? go buy a can of easy start spray the intake and crank her over if she fires then its a fuel problem if she dont then its spark, had a similar problem with my mito625 the problem was there was corrosion under the coil mount and i wasnt getting a good enough earth might be worth checking.

go careful with easy start. I've seen con rods come through the side of engines when it goes wrong. you say it was fine before. And you have only one plug not sparking. Well the plugs operate with wasted spark so two plugs fire at one time so its not electrical unless it was plugs. You have fuel so its not fuel starvation. Check you havent got sticky carbs and they are shutting down. May sound stupid but check you havent got something nesting in your airbox. seen that a few times. Check your battery is charged properly. And also if your plugs are wet you need to remove any excess fuel from the cylinders. I usually use a pen blow torch just to burn off any excess. keep us posted

Im with stripes on the easy start. If it dont run how will easy start fix the problem? You need a spark, fuel and compression at the correct time for the bike to run so these are the things to check.

i was suggesting its use as a diagnostic tool if there is a spark then the bike will fire if the timing is out it will back fire or fire through the exhaust, if it doesnt fire at all then there is no spark. ive seen rods exiting engines before but never after use of easy startusually its because the owner/tuner has asked too much of the components, must have had the thing pinned wide open or had problems with torque settings but as you pointed out im no expert.

easy start if in too high concentration ignites during compression and bend or exits a rod then. So be warned guys it nasty if it goes wrong

my gk71f cuts out at rest & is difficult to restart,i checked the plugs & their ok.it starts once it has cooled down,to check if it is a fuel prob i used petrol in a misting bottle squirted into the airbox (just a little sqirt)it starts so now i need to find out why it is starved of fuel when hot.hope this helps.
mike