49CC 2Stroke Engine help

[jayceehurricane]

hey guys,

yesterday i was driving my 2 stroke moped when all of a sudden i had power loss and pulled over, i realized my petrol tube that connects to my carb had splitten and fallen off so there was alot of petrol that had spilled out until my bike bogged out. i managed to swap tubes to a new one but now my bike feels really off, slow acceleration, takes time for engine to catch up with the RPM, higher revs, loss in horse power, any advice on whats happened or anything i can do to get her back to normal? 

thanks!

[jayceehurricane]

also noticing more smoke coming out of the exhaust, its a keeway hurricane 49cc

[pili]

Depending on how long it ran that way, the lack of oil is really tough on cylinder walls, pistons and rings, not to mention the crank and connecting rod bearings. Sounds like a rebuild is in order, good a time as any for a BBK!
You could pull the cylinder and see what's up on the top end, anyway.

[jayceehurricane]

Aug 28, 2024 14:05:36 GMT -5 pili said:

Depending on how long it ran that way, the lack of oil is really tough on cylinder walls, pistons and rings, not to mention the crank and connecting rod bearings. Sounds like a rebuild is in order, good a time as any for a BBK!
You could pull the cylinder and see what's up on the top end, anyway.

thanks for the info, from the gas tube falling off and to when i pulled over was the petrol running out from the carb and i felt the bike bog so i pulled over, the engines been kept well, ive been googling and ive read the vacuum in the cylinder might be off due to the air being sucked in, any thoughts on that? 

[aeroxbud]

Once fuel is filling the carb again. The vacuum on the cylinder should be normal within a couple of strokes.
Did you replace the line with a line of the same internal diameter?
If the fuel line is old enough to crack I would check over the vacuum line for cracking also. You should see a strong flow of fuel out of the fuel line. If you suck on the vacuum line.
I would
I also remove the plug and kick it over a few times. Just to be sure there is not excess oil inside the cylinder.

[jayceehurricane]

Aug 28, 2024 14:46:18 GMT -5 aeroxbud said:

Once fuel is filling the carb again. The vacuum on the cylinder should be normal within a couple of strokes.
Did you replace the line with a line of the same internal diameter?
If the fuel line is old enough to crack I would check over the vacuum line for cracking also. You should see a strong flow of fuel out of the fuel line. If you suck on the vacuum line.
I would
I also remove the plug and kick it over a few times. Just to be sure there is not excess oil inside the cylinder.

when you say the plug, thats the spark plug yeah? i was thinking about taking it out and checking on it. so i take the spark plug out and give it a few kicks to clear excess oil?

[jayceehurricane]

Aug 28, 2024 14:46:18 GMT -5 aeroxbud said:

Once fuel is filling the carb again. The vacuum on the cylinder should be normal within a couple of strokes.
Did you replace the line with a line of the same internal diameter?
If the fuel line is old enough to crack I would check over the vacuum line for cracking also. You should see a strong flow of fuel out of the fuel line. If you suck on the vacuum line.
I would
I also remove the plug and kick it over a few times. Just to be sure there is not excess oil inside the cylinder.

and yeah i changed the tube with the same tube, i had spare in my bike luckily, its just strange that before this happened the bike was strong and rapid, now it takes longer to get to max speed, ill rev the bike and it takes high revs to get going from stand still, up hill its slower, and it starts screaming when its idle

[aeroxbud]

That sounds like an air leak if it revs high at idle. It could also explain the lack of power.

[classacted]

it could be carbon buildup in the exhaust port and/or muffler