Suggestions needed 50cc bike problems

Right I've got another bike to work in today, it won't start, I've had the carb off fully cleaned out, there's a nice spark coming from the plug, but it just won't start I've tried putting a tiny bit of petrol into the head through spark plug hole still no luck, the guy said to me it was running before then he cut it out and came back like 10mins later trying to start it again but I wouldn't go? Any suggestions?

 

Is the plug getting wet with all the cranking?
Is fuel getting to the carb bowl?
Is there a cut out switch either on the bars or the stand?
Whats the compression like?

Got to go through the motions.

 

Yeah the plug is always wet when I pull it out, the compression isn't bad and nah there's no cut of switches, there's definitely fuel getting to the bowl it been cleaned fully, what do you think?

 

Take the plug out and hold it with the electrode just about sticking into the plug hole. Crank it over on the kickstart and see if you get a flash/flame out the plug hole.
If yes, then fuel delivery ok, compression probably shot even though it 'seems' ok.
If no, or very small flash, then could be faulty fuel vacuum valve.
Could also be that the plug has an earth fault after it is installed into the head. You'll never see this one in a million years. Had that problem on an NRG earlier this year. Chasing it for 3 days before I tried it. Stick a new plug in just to rule it out.

 

Okay cheers Steve ill give it a go tomoz, ill let you know

 

What scoot is this one?

 

Nrg power Dt with 70cc kit 2006

 

Most likely it will be knackered crank seals.

 

Mixture,
sticking choke,
grit in the jet?

 

Alright, how would I be able to know if its the seals? Would I be able to see anything?

Carbs sparkling clean

 

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how old is the bike, is the carb original to the bike
If it is the seals, you wont see anything physical, but you will see a drop in performance, if it is the carb try a new gasket kit, or a new carb, it may look clean but that doesn't mean it will work properly, just like my clean washing machine, that doesn't work either

 

Haha okay I'm working on it now ill let you know

 

sometimes you can take the variator off and see if the left seal is gone