80/66 cc engine not starting

[Petter]

Hi, i an just bought the 66 cc engine kit and can’t get it to run. I feel like I have checked everything. There is spark, carburettor gives off a mist which I think is the air/gas mixture when plug is removed, and there should be no air leakes. When I ride it I can simply hear the piston move, but I have to pedal it to keep I going and it’s simply producing no power. When I go down a steep hill I am able to go fast and car hear it fire once I a while as a show in the video below, but still can’t fire it up. Please help.

 

[YetiWoodz]

Have you engaged the choke? There is a lever on your carb. Depending on the carb you have, you either put it up or down. The choke restricts the flow of air so there is more gas in the fuel mixture. You need more gas in the mix when you're cold starting because gas doesn't evaporate well when cold. Once the choke lever is engaged, pedal and let go of clutch. Don't pull on the throttle yet. Once its firing more, give it a little throttle, if its firing more because of pulling on the throttle, then disengage the choke. Either by pushing the lever down or on a different carb, you pull all the way back on throttle and it disengages.

 

[wolframore]

What’s your spark plug gap set at? I had one recently where it looked like the spark plug was dropped and had no gap. Adjust to 0.024” if It’s off.

 

[mark20]

hows compression? sounds like a low comp issue.

 

[Petter]

I have trues several times starting it with And without the choke, it fires every once in a while but is not close to start. I’ve spoken with another guy as well and he said some compression leakage is normal as the piston rings are brand new. I have demounted and replaced the cylinder head and made sure it’s placed correctly. I have tightened the bolts with some force, so it should be no leakage from the cylinder. I have also bought a new spark plug as the local dealership said it was better quality than the stock one. It produces spark, but I don’t know if it is enough. Let me know if you want me to record anything. I have left of some videos where I go through the bike if you want to check it out.

Here is me actually getting the engine going. I was very shocked, but unfortunately couldn’t keep it going.


Here I go through the bike for the first time and address the situation. Simply just a visual video of the bike and components as it’s easier to spot the problem that way.


here I go through the carburettor and reinstall the cylinder head.


Here I sort out the tank and muffler problem, and explain a clutch issue. The clutch issue doesn't bother me as long as it doesn’t effect the engine running.

 

[Petter]

I have made a video about it now, thanks for the tips.

 

[mark20]

how much spark does it have? you could have a defective CDI

hows compression? does it go past your thumb if you turn the engine over, any resistance?

is your jet clean?

 

[Petter]

How do i check compression? I can blow through the jet so its not clogged.
Here is a video of the stock spark plug:
Here is a video of the bought spark plug:

 

[Chainlube]

That's a good spark. That gasket on the float bowl worries me, try making a new one out of a cereal box for the time being.

 

[Petter]

I tried with the previous carb as the gasket was crap as well. The cardboard simply just drowned and had no effect. The previous carb was leaking so I bought this one. However this one is not even dripping, I want to avoid adjusting it as much as possible for now as I don’t want to rip the gasket any more. Do you think I should wait and see if it will leak, or try to clog the gasket? Either way I don’t think the carb is the problem, as I have tried two different ones, and adjusted the several times.