Let’s face it, no one likes pulling out engines just to check cam tensioners. This guide shows you an easy way to verify if your Hyosung has an updated cam tensioner or a faulty batch.
Applicable models:
- 2007-2018 GT125 Naked / GT125R / GV125C Aquila / GV250 EFi / GT250 EFi / GT250RC EFi
Open both the front and rear engine covers and use a bright torch to see inside.

Look carefully inside both cylinder heads.

- If you see a FLAT TIP tensioner → Take it to your dealer and replace immediately. Faulty springs cannot be repaired and may cause serious engine damage.
- If you see a CURVY / DOME TIP tensioner → You’re fine; no action needed.
- Do NOT use manual tensioners on street bikes—they require experience and risk engine damage.
- If any automatic tensioner makes noise → Replace it, and check valve clearances and chain health.

New tensioners can be sourced from your local dealer or mechanic. Make sure to include bolts and O-rings.
- Always use the supplied O-ring to avoid oil leaks.
- Do not adjust the automatic one-way type tensioner.
- Only use a tensioner designed for your exact model (GV125 / GV250 / GT125 / GT250).
- If you need help sourcing a tensioner, contact me with bike details.

Always use a new gasket when fitting a new tensioner:
- OEM gaskets are available here.
- As a last resort, automotive gasket paper can be used—but avoid cereal boxes!

If you live in remote areas or your mechanic refuses the job, use the service manual and study YouTube tutorials for similar V-twins. Mistakes here can destroy your engine.
If you have questions about other bike issues, post a new topic!
PS: Yes, the rear engine is always the least fun part!
