little power

forehead949

New Member
Feb 7, 2009
9
0
0
San Ramon
hey guys.
i recently started up my 80cc engine and realized that the engine was putting out very little power. it was less than 10mph. my fuel ratio was 16 to one, which may be too rich, and the intake manifold gasket was torn apart. im pretty sure that the carb is functioning properly. i was just wondering all the possible reasons why i dont have power. The engine also has a hard time idling and will stall. i guess my main question is... could too much oil/small air leak cause the motor to not have any power/torque whatsoever?

what was interesting is that when i would pedal assist really hard, the rpms would go up and it was able to maintain a fairly high speed.

any thoughts are appreciated:)
 

Clotho

Member
May 25, 2008
304
1
18
I would check a few things. First start with the plug. It isn't uncommon for them to become oil fouled during the break in period. If you are running the original Chinese one then you will want to change it for a NGK B5HS or B6HS. Sick Bike parts carries them if you need one. I would check the head bolts for tightness too.

After that I would check the intake and carb for leaks. I spray carb cleaner around the joints on mine and if the engine loses rpm I know I have a leak.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
236
63
up north now
hey guys.
i recently started up my 80cc engine and realized that the engine was putting out very little power. it was less than 10mph. my fuel ratio was 16 to one, which may be too rich, and the intake manifold gasket was torn apart. im pretty sure that the carb is functioning properly. i was just wondering all the possible reasons why i dont have power. The engine also has a hard time idling and will stall. i guess my main question is... could too much oil/small air leak cause the motor to not have any power/torque whatsoever?

what was interesting is that when i would pedal assist really hard, the rpms would go up and it was able to maintain a fairly high speed.

any thoughts are appreciated:)
You have diagnosed your own problem....mix some fuel up at 24:1 and fix that gasket!
 

forehead949

New Member
Feb 7, 2009
9
0
0
San Ramon
thanks guys.
about the spark plug. mine is a bit dark from the oil but it still sparks. could the oil residue greatly affect the power on this thing. cause when i forst started it up(when the plug was fresh) it was not any better.

meh?

im assuming it is a leak then. and my fuel is too rich.
 

Technocyclist

Motorized Bicycle Senior Technologist
Jul 7, 2008
463
0
0
Asia
air leak you say... check out the oil seals... repack the oil seals with grease...and seal the edges with a head gasket maker...

the oil seals tend to pop out...
 

justthisguy1292

New Member
Jan 16, 2009
39
0
0
Massachusetts
where are these gaskets and how do i tell if there is a leak? i crashed a little bit after losing traction in some sand and i've lost a bit of power. nothing seemed to be damaged cuz i took most of the beating. i used to be able to get to 30mph pretty easily but now it struggles to hold 24. i've tightened the head bolts, cleaned out carbon deposits, taken apart the carb and cleaned it a little bit and nothing helps. i'm pretty stumped. I think i'm using a 16:1 ratio for gas but that worked fine before the crash. I've put about 150 miles on it.
 

forehead949

New Member
Feb 7, 2009
9
0
0
San Ramon
hey man. im new to this so dont rely on me. i have been told to bump up he gasoline ratio after break-in from 16:1 to around 25:1. i bet you would get more power if you have less oil. and check your intake manafold gasket and all your seals in the carb for leaks.
thats my two cents
 

Cabinfever1977

New Member
Mar 23, 2009
2,290
1
0
Upstate,NY
fix the gaskets and seal everything up,its not the plug or oil/gas ratio but you should up it to 25:1 now.
plus something could have got damaged from the crash,check throttle and clutch cables.
 

Technocyclist

Motorized Bicycle Senior Technologist
Jul 7, 2008
463
0
0
Asia
hay mate this is happening 2 my bike do u have 2 pull motor apart or can u do it by just taking magnet off any pics would b handy thank u
:-||
You don't have to pull the motor apart but you do have to remove the magnet and the small sprocket. Be careful not to loose the halfmoon woodruff. If you ignore this problem, there's a possibility that the oil seal can get eaten up by the small gear. Also, the oil would spread to your clutch, rendering it useless. Unless your engined seized up first. It's a bit tricky putting back the magnet. Takes some practice and patience. :-||