jerking under 7 mph

oldmanpaintball

New Member
Jun 22, 2008
47
0
0
surprise az
when i engage the engine to turn over .it starts up but it jerks back and forth . i give it gas and its fine after 7mph .i can disengage the clutch and keep the motor in idle and rev it up fine .
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
That's because 7 mph is too slow, go to ten or better before you let the engine do the work.
 
Last edited:

oldmanpaintball

New Member
Jun 22, 2008
47
0
0
surprise az
if iam going down a hill and iam freewheeling down with the engine on .iam at the bottom now going around coasting when do i engage the motor .do i need to slow to 3-5 mph . whats the best way to approach this ?
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
I almost always coast going downhill (clutch pulled). I would just rev it up to meet the wheel speed when I was ready to re-engage the clutch. It's something you get a feel for, start at lower speeds when practicing.
 

Skyliner70cc

Member
Mar 8, 2008
138
0
16
I don't recommend coasting downhill. Most bikes have some partial clutch engagement when the clutch is locked-you'll notice that the locked clutch position is not at the maximum point of clutch engagement. To check if this is your situation, start your bike and lock out your clutch. Pick up the rear of the bike to lift the tire off the ground and rev the engine. If the tire spins ever so slightly and it probably will while locked, it means that you may increase wear or glaze the clutch friction pucks if you coast down hill with it in the locked position. Check to see if the wheel spins with the clutch fully depressed by hand (not locked) and you'll see that it usually doesn't.

Yes, this occurs with a well adjusted clutch. If you try to completely disengage the clutch in the locked position, odds it won't fully engage or possibly slip when it is released for a start. THe situation worsens if you use one of those extra long levers.

There is no harm done in coasting down hill with engine engaged. If you need to go slower while in gear, then a 48, 50, or 55 tooth sprocket is your best bet.
 

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,843
235
63
up north now
I've never had any problems with coasting- just pull in your well adjusted clutch and let gravity do the work. It doesn't hurt the clutch pads.

Now if your clutch is not adjusted right, it may cause a tiny microscopic amount of wear.

What is not recommended is prolonged periods of downhill, throttle off, clutch engaged "coasting".

...and why is that Mr. Skyliner?
 

Dave31

Moderator
Staff member
Mar 1, 2008
11,204
28
38
Aztlán, Arizona
I coast all the time, motor running clutch in. I've gone down Mt. Lemon a 18-21 mile trip down the moutain many times. Five years over 4,000miles, not once have I adjusted my clutch.
:ride2:
 

ran49

New Member
Mar 5, 2008
186
1
0
So.In.
On lesser hills where over reving is not a problem and your too lazy to screw with the clutch,Yeah,I can be pretty lazy.Instead of totally letting off the throttle which causes the wheels to turn the motor and results in a certain jerkiness on my bike,I find if you use just enough throttle to keep the motor up with the wheels it's a whole lot smoother.I even do this while braking since I'm not adding any power to the wheels.Ron