80CC Tops out at 18???????

the_edge150 · #1 01-30-2009, 01:00 AM

Ok i just bought a new 80cc from Raw motors in hacienda heights,ca for 95 bucks new, and i switched out the parts on my bike except for the sprocket, and the sprocket that came with is the same size as the one already on there, but it only goes 18MPH???? what did i do wrong that its doing this??

BTW: if anyone wants my old 50cc block and can pick it up,PM me ,and its yours for free

NunyaBidness · #2 01-30-2009, 01:12 AM

There may be an air leak somewhere. If you choke it and it doesn't die, then you do have an air leak.

the_edge150 · #3 01-30-2009, 01:20 AM

it takes about 3 seconds to die after choking it

fm2200 · #4 01-30-2009, 02:12 AM

Hi edge, What rear sprocket do you have, if its 44T or more your rpms will run high and not much speed. I changed mine to a 40T and its a little better about 22-24mph If I try to go any faster the vibration takes over making you tingle all over. Im gonna try a 36T next and see what that does. I also have a 80cc but the ratio ( rear sprocket ) is the main factor not the size of your engine.

Creative Engineering · #5 01-30-2009, 08:45 AM

Quote:

Originally Posted by the_edge150

Ok i just bought a new 80cc from Raw motors in hacienda heights,ca for 95 bucks new, and i switched out the parts on my bike except for the sprocket, and the sprocket that came with is the same size as the one already on there, but it only goes 18MPH???? what did i do wrong that its doing this??

BTW: if anyone wants my old 50cc block and can pick it up,PM me ,and its yours for free

There's no mystery here.

Either the clutch is slipping, or the engine simply isn't revving.

Remove the air filter. Twist the throttle wide open, and look inside the throat of the carb to make sure the slide is in fact all the way up.

Jim

Ghost0 · #6 01-30-2009, 10:10 AM

You might also check the intake and exhaust gaskets and manifolds to see they are clear as well as checking that the pipe is not restricted. Also remember it takes 50 to 100 miles before they are broken in and produce optimum power.

the_edge150 · #7 01-30-2009, 10:47 AM

i think it might be the clutch slipping, because i hear a whining sound from the bike,and it might be out of adjustment, and its really hard to pull.just in case, i'm going to put teflon tape on the manifold in case of a leak.

**2door** · #8 01-30-2009, 03:57 PM

Quote:

Originally Posted by the_edge150

i think it might be the clutch slipping, because i hear a whining sound from the bike,and it might be out of adjustment, and its really hard to pull.just in case, i'm going to put teflon tape on the manifold in case of a leak.

Teflon tape on either manifold, intake or exhaust won't work. If you're talking about the manifold to carburator area, use silicone or a paste gasket sealer. I use a Loctite product, #515. Use it sparingly, you don't want it getting sucked in, just enough to seal the carb to the manifold.
This also might sound silly but how are you estimating your speed? My first speedometer wouldn't go over 19MPH. I didn't know I could hit 30 until I got a new speedo and confirmed it with my wife driving next to me in her car.
Tom