No Gas In Fuel Line and Lots of Vibration

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dudeman

New Member
Jan 15, 2009
2
0
0
Holland MI
I have a Grubee Gen II Engine with the Special Flange Mount Carburetor that mounts direct to the cylinder head. It runs but I can't understand why when I shut it off there is no gas in the transperent gas line. Be aware with this new carburetor mounting location the clutch cable stop hole in the case is right behind the carburetor fuel bowl and does't allow a good line for the cable to the clutch arm. Some more of that great engineering. It also has excessive vibration which I can't seem to cure with adjustments. Any help with these situations would be appreciated.

Thank You,
Dudeman
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Nothing you can do about the vibes....it's the nature of the beast.

As for the gas line- does the bike run o.k.? If so, keep an eye on it so you don't get a lean condition and maybe look for sources of fuel blockage (in tank screen, ect.)
 

spad4me

New Member
Jan 20, 2008
472
0
0
Arizona Bullhead
An air leak between the carb and the engine.
A pinched or dirty fuel line, dirty Carb badly adjusted needle, that does not let enough gas oil mix into the engine. to properly cool and lube the internal parts.

Apply your choke while the engine is running.
Slowly, apply full choke.
Does the engine seem to run better at partial choke. BAD

Does it die at full choke when warmed up? GOOD

If the engine seems to run better with partial choke applied you have a lean condition. BAD

On mine the gasoline initially flows in a thin stream in the line then fills it up.
 

Cowboy Rider

New Member
Apr 20, 2009
75
0
0
Illinois
Hmmm...

My fuel line is never FULL either. Seems to run OK, except at the top end. At that point, it almost seems to be starving for fuel. I wonder if I should blow the fuel line out with air pressure in reverse to make sure there's no blockage at the tank. ?
 

Road82

New Member
May 1, 2009
7
0
0
Portland, Oregon
Squeeze the fuel line with your fingers below the fuel filter. Let go and you will see a trickle of fuel and some bubbles. Keep doing this till the fuel live fills up.
 

ebmvegan

New Member
Jul 15, 2008
283
0
0
OC, Ca
I have a Grubee Gen II Engine with the Special Flange Mount Carburetor that mounts direct to the cylinder head. It runs but I can't understand why when I shut it off there is no gas in the transperent gas line. Be aware with this new carburetor mounting location the clutch cable stop hole in the case is right behind the carburetor fuel bowl and does't allow a good line for the cable to the clutch arm. Some more of that great engineering. It also has excessive vibration which I can't seem to cure with adjustments. Any help with these situations would be appreciated.

Thank You,
Dudeman
You may have to change the petcock as well. They're known for flow issues.
 

Norman

LORD VADER Moderator
Jan 16, 2008
2,606
7
38
71
pampa texas
my fuel line does that too if it stops running and has fuel I use lung pressure to pressure up the fuel tank and go on my merry way don't do this with people standing around watching they will think your huffing gas and do not inhale doing this is a crude and rude way of doing something but it works. I hate to pedal the dang thing.
Normandnut
 

floridaboy

Member
Apr 25, 2009
139
6
18
Hudson, FL.
I also have a Gen II engine and the same fuel line problems. My bike seams to run allright but the gas only trickles down the gas line and shows up in the last 2 to 3 inches. What do you all think of the low in power of your Gen II engines? Mine is leak and was told they were detuned to meet import standars. Trying to find what inprovements that i can make to boost the low end torque. If you know of anything that helps let me know.
 

Cabinfever1977

New Member
Mar 23, 2009
2,288
1
0
Upstate,NY
that fuel line problem has nothing to do with your engine.
maybe the petcock or petcock intake filter?
or the float needs adjusting in the carb?
or maybe something up with your carb?
try a smaller gas line,i did and now i have no air in my line at all.
also a airleak will cause air to enter the line from the carb.
 
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