Engine Trouble Engine won't start

[Dao30luu]

80cc bike engine in break in period . After a ride , I see bubbles coming in the fuel filter line , then I won't be able to start the engine since then . Can anyone help , thanks !

 

[Dao30luu]

 

[Frogslayer]

You try the tickler button? It's your carb hot to the touch?

 

[Mcdonns]

80cc bike engine in break in period . After a ride , I see bubbles coming in the fuel filter line , then I won't be able to start the engine since then . Can anyone help , thanks !View attachment 90147

Can’t tell from that angle how close the filter/line is to the head. If you’re fully open on the fuel valve, no restriction at the Tank strainer, and the choke is off, that almost looks like you’re vapor-locking.

There’s also some visible oil at the base of the plug, so there’s a question whether you may be blowing combustion gas past the crush washer, which would make it even hotter right there.

 

[Dao30luu]

Can’t tell from that angle how close the filter/line is to the head. If you’re fully open on the fuel valve, no restriction at the Tank strainer, and the choke is off, that almost looks like you’re vapor-locking.

There’s also some visible oil at the base of the plug, so there’s a question whether you may be blowing combustion gas past the crush washer, which would make it even hotter right there.

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[Mcdonns]

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That really does look like a boil-off, but it’s odd to see it happening so quickly and down the entire length of tubing. It definitely could be a LOT of heat there, somewhere, but...

One other thing could be how you’re sequencing your shutdown, after a ride. Another way I could see this happening would be closing the fuel petcock with the engine running, then letting it run ‘til the bowl runs dry. This would cause fuel still in the line to still try to drain out, if the bowl is empty, the float is down, and the fuel valve is closed. It would only do it for a short bit (‘til the line emptied, or the float raised back up on a full bowl), but would leave you with air in the line on the next start-up, as well as a flushed mix out of the case. This could complicate/delay restarting, especially without choking again (hot OR cold), ‘til enough fuel has again filled the line and bowl to be picked up by the pitot, and the mix in the case is recharged. Again, what’s your typical shutdown sequence, after a ride?

 

[Dao30luu]

Right away

 

[Dao30luu]

Another thing , the fuel is leaking too . Should I change the fuel filter and fuel line ?

 

[Dao30luu]

You try the tickler button? It's your carb hot to the touch?

Yes . I didn't touch the carb .

 

[Lunatuck]

I was going to ask where all that gas was going. Wonder if your float is stuck and you have a leak. Take the carb off, and look it over really good. It also looks like you could be getting an air leak around the intake.