The kickstarter moves, but it is very heavy near the top of the stroke, or it stops as if against a wall. The cause is usually the compression stroke itself, a compression release that does not work, or a drag somewhere in the engine or drive. A kick that does not move at all is a different fault: Kickstarter will not move.
Is it safe to ride?
Do not ride until it starts normally. A heavy kick is a sign of a fault, and a kick that suddenly gives way can throw the foot off the pedal.
Quick checks first
- Stand on the kickstarter in the correct way: bring the piston just past the compression stroke, then give a firm, even push. Many big singles need the lever brought to the right place first.
- Bike in neutral. Many bikes cannot be kicked in gear.
- On an engine with a compression release lever, pull the lever and kick. Does the kick become lighter?
- Is the clutch lever pulled? On some bikes the kickstarter turns the engine through the clutch, so it only works with the lever released.
Diagnose it step by step
1With the plug out, is the kick now light?
- Yes: the compression is the cause of the effort. Go to step 2.
- No: something else drags. Go to step 4.
2Does the engine have a compression release (lever, cable or automatic cam)?
- Yes: check that it works and that the cable has free play. Check a manual or automatic compression release.
- No: go to step 3.
3Is the compression normal for the engine?
- A very high reading on a tuned engine can be normal. Compare with the manual. Rough compression check with a thumb is enough to tell if there is strong pressure.
- Compression much higher than normal, such as after a cylinder head or piston change: ask the workshop to check the parts fitted.
4In neutral, does the rear wheel turn freely?
- No: brake, chain or wheel drag. Remember that this does not affect the kick on most bikes, but it tells you the drive line is not locked.
- Yes: go to step 5.
5With the plug out, does the engine turn by a spanner on the crankshaft nut?
- Yes, freely: the fault is in the starter gears. Find out where a stuck engine is locked.
- No: the engine is stiff. Go to Engine has seized or locked up.
Never force the pedal harder. Force only breaks gears, ratchets and the return spring.
Causes, most likely first
| Cause | How to confirm | Fix |
|---|---|---|
| Piston not at the right point for the kick | Kick is easy when the pedal is moved to a better place first | Kick technique |
| Compression release lever or cable stuck | Lever not moving, no free play | Check a compression release |
| Normal high compression, no release fitted | Plug out: kick is easy | Manual check |
| Engine stiff or seizing | Crankshaft will not turn with a spanner | Stuck engine diagnosis |