A Suzuki GSX-S150 with a noisy chain is usually too slack, too dry, running on worn sprockets or sitting out of line. Because the drive is fully exposed, each of those can be checked in a few minutes with the bike on its stand.
Before you start
A chain that breaks or jumps can lock the rear wheel. Never inspect a moving chain, never reach near the sprocket with the engine running, and always fit the master-link clip in the correct direction.
Machine file Suzuki GSX-S150
- Engine
- Liquid-cooled DOHC four-valve single
- Cooling
- Liquid
- Fuel
- Fuel injection
- Transmission
- Six-speed manual
- Final drive
- Chain
Set the reference correctly
Measure the chain's movement at the midpoint between the sprockets, with the bike in the position the manual specifies. A reading taken on the side stand will not match a specification written for an unloaded rear.
Compare the result with the manual figure. Too much slack lets the chain strike the swingarm and skip under power; too little loads the output bearing and shortens the life of the chain and sprockets.
Noise and the part to inspect
| Noise | When | Check |
|---|---|---|
| Rattle over bumps | Rough road | Chain slack |
| Rhythmic tick | Once per wheel turn | Stiff link |
| Scrape under power | Acceleration | Alignment |
| Constant rasp | All the time | Lubrication or slider |
| Buzz at one speed | Steady throttle | Cover bolts |
| Rumble with speed | Coasting too | Wheel bearing |
Look for the stiff link
Turn the rear wheel slowly and watch the chain pass the sprocket. A stiff link stays straight where the others bend, and it makes a tick once per revolution that no amount of adjustment will remove.
Clean and lubricate and check again. If the link still will not flex, the chain is finished. Replace it before it damages the sprockets or breaks.
Read the sprocket teeth
Rear teeth that hook forward and a chain that rides high in the valley mean the set is worn. The front sprocket is smaller, turns more often and usually wears first, even though it is partly hidden.
Change chain and sprockets together when either is worn. A new chain running on hooked teeth wears out fast, and a new sprocket with a stretched chain does the same.
Alignment and torque
A rear wheel that is not square makes the chain run against the sprocket shoulder. The result is a scrape, edge wear and a noise that changes with load rather than with speed.
Confirm alignment with a straight edge or string line, tighten the axle to the specified torque, then measure the slack again. The adjustment often changes as the axle seats, and a chain set on the loose side of the range before tightening can end up outside it.
Sliders and the front cover
The swingarm slider and the guide near the front sprocket keep the chain off metal. Once the rubber wears through, the chain grinds the aluminium and the noise becomes a rasp under load.
Inspect the slider for depth and the guide for cracks, and check the cover bolts. A loose cover buzzes at a particular engine speed and is often mistaken for a gearbox fault.
Noise that is not the chain
A rumble that follows road speed and continues while coasting comes from the wheel or the bearings, not the drive. A squeak over bumps is usually a dry pivot or a loose exhaust joint.
With the engine off, spin the rear wheel and listen at the hub and at the sprocket. If the noise remains after a correct adjustment and a clean chain, investigate the bearings.
Keeping it from coming back
An exposed chain is easy to inspect, which makes prevention straightforward. Measure slack as the manual specifies, clean and lubricate after rain, and check alignment after wheel changes. Replace chain and sprockets together when the teeth hook or a link will not flex.
A short checklist
- Measure slack with the bike as the manual specifies.
- Rotate the wheel and look for stiff links.
- Inspect both sprockets for hooked teeth.
- Verify alignment with a straight edge.
- Check the slider, guide and cover bolts.
- Spin the wheel to rule out a bearing.
Questions owners ask
Why is my GSX-S150 chain loud after I adjust it?
The wheel may not be square, or the slack was set with the bike in the wrong position. Recheck alignment and measure again with the suspension as the manual describes.
Can a chain be too tight?
Yes, and it is worse than too loose. A tight chain loads the output bearing and can damage the gearbox seal every time the suspension compresses.
How often should I lubricate the chain?
After a wet ride and at regular intervals in dry weather. A chain that looks dry or sounds raspy needs lubricant before the next ride.
