Brand new bike, won't go

GoldenMotor.com

virgilpilgrim

New Member
Aug 18, 2009
6
0
0
texas
hi guys, total newbie here. I just installed my new 48cc after one week of trying. at the last minute the throttle kill switch and ground wires broke and i soldered them back.

so here is the problem. i pedal to start the bike by engaging the clutch. the bike then starts with the forward momentum and clutch engaged, but will not accelerate.

and when i release the clutch the bike dies immediately. is it an electrical problem linked to the throttle, or, do i have the carb not adjusted well? the bike sputters into life but dies immediately. i was only able to get about 30 ft so far. scratg

tantalizingly close, please help me out. please be patient with me, as i said; newbie. thanks!
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
It seems like a fuel, fuel valve, or carburetor problem to me.
The carburetor and ignition are in no way mechanically or electrically connected to each other.
The closest you can get to that notion is that the kill button is housed in the same piece of plastic as the throttle grip assembly. They just share a common non electrically conducting housing.

I would start by doing a search on this site, and /or reading the 2-stroke section.
Your problems have all ready been thoroughly discussed in great depth. The threads can explain it all better that I can in this post.
Good luck, and don't give up or throw heavy objects at it. These engines are very simple and carb problems are simple to fix, just tricky to properly diagnose some times.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
If you are sure the engine is firing, and not just turning over-
Push the primer button down and hold it for two seconds.
Pull the choke lever up 3/4 of the way.
Pedal up to a good cruising speed and release the clutch.
Crack the throttle open a little and see what you get.
 

virgilpilgrim

New Member
Aug 18, 2009
6
0
0
texas
thanks guys. you might be right about the carb. it came assembled, so i assume it was ready to go. what should i check for?

and yes, the engine fires. it sputters.

oh by the way, when i turn the fuel on, there is a leak from the carb, so more fingers pointing to it?
 

virgilpilgrim

New Member
Aug 18, 2009
6
0
0
texas
The leak is from the carb, but i don't know where. it is not massive.

i think my real problem is electrical. i don't thin the spark plug is not connected properly to the ignition coil. to test it, i disconnected the coil and the performance is exactly the same; the engine starts with the momentum of the bike after a quick pedal. but then cannot maintain that and immediately dies when there is no load on it.
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
That seems like the engine is not actually starting at all. As though you are just hearing the intake and exhaust making a "puta puta puta puta" sound as the piston moves up and down.
If you disconnected the ignition coil there is no way the engine can run.
Now you say that the sound did not change, coil connected or not.
The logical conclusion is no, you have not yet heard the engine start.

Perhaps these links can be of help:
http://motorbicycling.com/f30/check-cdi-magneto-w-multimeter-8706.html
or
http://motorbicycling.com/f30/how-wire-chinese-2-stroke-bicycle-1996.html
or
http://motorbicycling.com/f39/motorized-bicycle-carburetor-install-rebuild-302.html

All I did was a quick search of this site.
I hope it helps you. Nearly every problem or question regarding troubleshooting or repairing these little engines has been covered at one time or another.
This forum is awesome! .bld.
 

hi4noon

New Member
Jul 21, 2009
23
0
0
Massachusetts
i had the leak from the carb as well. what i did was reduce the fuel into the carb via the lever on the carb not the fuel tank until it stopped. Now that interfered with the acceleration as i guess no enough fuel was getting to the engine so i reopened it fully and it doesnt leak anymore...

I know that doesn't provide a logical/defined solution but it worked for me :)
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
Hmmmm...... If you are are talking about the GruBee 2 strokes, the only lever on the carburetor I am knowledgable about is the choke lever.
Used for cold weather starting.
 

hi4noon

New Member
Jul 21, 2009
23
0
0
Massachusetts
um, i have a grubee gt5 2 stroke. Where the fuel line connects to the carb there is a white lever/knob thingy. I know, very technically sound description :).
 

GearNut

Active Member
Aug 19, 2009
5,104
11
38
San Diego, Kaliforgnia
Don't know that one.
I am referring to the GruBee starfire or one of it's many clone breatherin.
Happy times, China girl, ect......
Edit:I just looked up your engine on BikeBerry's site.
SkyHawk GT5. The exact engine I am referring to. Yours must have the new carburetor I have heard about...???
 
Last edited:

hi4noon

New Member
Jul 21, 2009
23
0
0
Massachusetts
yup, i looked into it a bit, http://www.bikeberry.com/installmanual.pdf on page 8 top photo on the right the new carbe comes with a fuel shutoff valve now.

You had any problems with the China engines? Mine broke after 45 mins of riding, sheared the clutch shaft thread so the drive gear won't stay on. There are a couple threads on the forum bashing china engines.
 

virgilpilgrim

New Member
Aug 18, 2009
6
0
0
texas
That seems like the engine is not actually starting at all. As though you are just hearing the intake and exhaust making a "puta puta puta puta" sound as the piston moves up and down.
If you disconnected the ignition coil there is no way the engine can run.
Now you say that the sound did not change, coil connected or not.
The logical conclusion is no, you have not yet heard the engine start.

Perhaps these links can be of help:
http://motorbicycling.com/f30/check-cdi-magneto-w-multimeter-8706.html
or
http://motorbicycling.com/f30/how-wire-chinese-2-stroke-bicycle-1996.html
or
http://motorbicycling.com/f39/motorized-bicycle-carburetor-install-rebuild-302.html

All I did was a quick search of this site.
I hope it helps you. Nearly every problem or question regarding troubleshooting or repairing these little engines has been covered at one time or another.
This forum is awesome! .bld.
yes, the engine was just turning over. i was mistaken in my excitement. it seems the ignition is not working.

i will check the links.
 

virgilpilgrim

New Member
Aug 18, 2009
6
0
0
texas
plus how can i make sure the spark plug is touching the contact in the coil. there is no screw and i don't think current is going to the plug
 

hi4noon

New Member
Jul 21, 2009
23
0
0
Massachusetts
I have the Grubee GT-5 and the spark plug snaps into the ignition coil. I first needed to unscrew the small cap on the tip of the spark plug.