Engine Trouble Motor runs at idle but doesnt accelerate

[Beastiebikes]

So my new 50cc engine was running fine for a few days after building. Now it starts and runs with the clutch pulled in. But doesnt have any power i have to pedal to the speed i want then it barely keeps that speed losing power over time. This is what my intake looks like. I feel like i dont have enough gap for air fuel to enter. Please give me your opinions

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• Beastiebikes
• Dec 26, 2017

piston clearance issue

 

[crassius]

looks just right - have you checked compression or looked closely for oil residue indicating leakage

 

[Beastiebikes]

I did and found some oil residue on my spark plug. Ill be bleeding out my gas and adjusting my oil fuel mixture to test if my oil was bad.
https://scontent-dft4-3.xx.fbcdn.ne...=eb206442af126117543084850c4f22e0&oe=5AB8D27B

 

[Frankenstein]

I think you're too rich, that plug looks like utter crap. Maybe part of the problem is it's chocked over totally by carbon, you'll get a very bad spark and not much power with a fouled plug. Try putting a clean one in. If a new plug doesn't help then start looking at the electrical system, if you have a failing cdi or mag then you'll also get a bad spark which will lead again to your plug fouling.

 

[crassius]

look for the usual over-rich stuff - main jet loose, choke sticking on, float sinking

 

[Frankenstein]

...and before I forget check the muffler header, I used an oil that just outright clogged the exhaust port/header with soot/carbon, if the exhausts can't escape fast enough it will really affect how well the engine runs, if it's bad enough it won't run at all. Seeing you can idle (low speed rpms means the exhaust doesn't have to escape as quickly) but loose power at higher rpms, and you have some nasty looking plug life, I'd say there's a medium chance that you have a constipated engine.

 

[Beastiebikes]

...and before I forget check the muffler header, I used an oil that just outright clogged the exhaust port/header with soot/carbon, if the exhausts can't escape fast enough it will really affect how well the engine runs, if it's bad enough it won't run at all. Seeing you can idle (low speed rpms means the exhaust doesn't have to escape as quickly) but loose power at higher rpms, and you have some nasty looking plug life, I'd say there's a medium chance that you have a constipated engine.

How would I check the muffler header for blocked flow, I blew into the muffler after removing it and it didn't feel restricted what else can i do?

look for the usual over-rich stuff - main jet loose, choke sticking on, float sinking

what else can i do besides checking the carb, i went over fuel flow inspected the float and the jet. it all looked good without any gunk in or around

 

[crassius]

for muffler, just loosen it about 1/8th inch or so and run it - for jets use a tiny piece of copper wire thru jet and then spin jet on the wire - also check float height by turning carb upside down with bowl off, put float on and look over top of float to see jetis barely peeking up thru hole in float

 

[Beastiebikes]

success, good and bad news. Bike runs perfectly without an exhaust. I swapped exhausts but the bike wouldnt start so i went back to no exhaust and it started up fine again. what could that be?

 

[Street Ryderz]

success, good and bad news. Bike runs perfectly without an exhaust. I swapped exhausts but the bike wouldnt start so i went back to no exhaust and it started up fine again. what could that be?

look at post #6 again seems like thats what's going on.