Engine bogging down

eriksen · #1 (**permalink**) 03-30-2009, 07:49 PM

I have a 48cc motor on my bike two weeks old, way past break in period. The top speed was at 30mph. I was riding it last night at full throttle off and on for about twenty minutes. During the end of that twenty minutes it started to bog down, and struggle. I rode it again today and for the first 5min it ran fine, but then bogged down again. It gets to 20mph but at full throttle, and then slows down to 16mph. The throttle will be completely down and nothing happens. It will run at 16mph will it slows down and pick back up again to 20mph, and this will repeat. When the clutch is in the throttle revs fine, but in gear it struggles. After a cool down the engine runs again fine for a few minutes then bogs down again. Any help, I don't know much at all about engines. Also if it matters at all the mix ratio has been at 16:1.

Sidthekidd11 · #2 (**permalink**) 03-30-2009, 08:03 PM

this is the same thing that is happening to me please help....also i feel like the engine is starving for more fuel any help is appreciated

MB-Monkey · #3 (**permalink**) 03-30-2009, 08:09 PM

your mixture is off mix a batch of fuel at 24:1 conventional oil get a new spark plug and see what happens i bet it will start acting better

Creative Engineering · #4 (**permalink**) 03-30-2009, 08:11 PM

Hey guys,

I did a thread awhile back on assembly defects.

Assembly defects

These engines are very simple...If it's loosing that much power, there is something wrong that will only get worse.

Dpending on who you bought it from, you may have no recourse other than to tear it down and fix it yourself.

Jim

Finfan · #5 (**permalink**) 03-30-2009, 08:17 PM

Do you have a fuel filter? Try checking that it could be gummed up from a new tank. Also open up the carb and spray it out with some carb cleaner. It sounds like you are either not getting enough fuel or enough air. Make sure the choke is functioning properly also.

eriksen · #6 (**permalink**) 03-30-2009, 08:22 PM

Will try new mixture and spark plug. No fuel filter. engine has a 6mo warranty from gasbike.net. will be back in 30 minutes after trying new mixture.

Sidthekidd11 · #7 (**permalink**) 03-30-2009, 08:23 PM

well now tht you metion the choke i cannot start the engine with the choke down and when i start it up with the choke up when i put it down the engine shuts off. as you probally already noticed im new to bike engines and motors. i have narrowed it down to a couple possible reasons 1)not enough fuel 2) not enough air 3) mixtues wrong please help!!!

thanks

eriksen · #8 (**permalink**) 03-30-2009, 08:29 PM

Cleaned out carb last night before I ran it for 20 minutes, thats when it ran its best until it started to bog down for the first time.

Sidthekidd11 · #9 (**permalink**) 03-30-2009, 08:32 PM

well now tht you metion the choke i cannot start the engine with the choke down and when i start it up with the choke up when i put it down the engine shuts off. as you probally already noticed im new to bike engines and motors. i have narrowed it down to a couple possible reasons 1)not enough fuel 2) not enough air 3) mixtues wrong please help!!!

thanks

Creative Engineering · #10 (**permalink**) 03-30-2009, 08:41 PM

MB & Fin are right!

Check out the simple stuff first!

I've had so many of these apart that I have lost sight of the trees while looking at the forrest.

Hopefully it will be something that can be fixed easily. 99% of the time, it is something simple.

Jim