Honda CG125 gearbox trouble

[anogio]

I really hope someone can help me please...

I was turning a corner the other day (dunno if that's important), and suddenly a grinding/scraping sound started coming from the gearbox (at least i think its the gear box), and the chain went really slack. I pulled over and check the bike over (which is when i noticed the slack chain). being a foresighted sort, i always carry some spanners, so I tightened the chain again, but the noise has persisted. I had a look through my haynes manual, and the only bit I could see was a bit that said "Excessive mechanical noise: broken pinions". Whatever that means

Could someone help me, by giving me an idea what's wrong with my bike, and a rough idea of how to fix it? It's worth noting that apart from the loud noise the bike runs as normal, but im too scared to take it out on the road now in case it gets worse

Thanks in advance

[Spoon261]

I am no repair mechanic, my expertise is just in normal servicing
So I can not advise what’s wrong and what to check.

I have had a gearbox fail on me on a totally different make of bike.
Its no fun, pulling in the clutch does nothing, since the gearbox is directly connected to the chain and back wheel. The clutch simply disengages the engine from the gearbox.

The chain repeatedly going slack was ether caused by excessive braking from the engine/gearbox (gone faulty) or the chain is just worn out.
If the chain is simply worn out, it would cause noise and also effects the feel of the gearbox when changing gears and of course the engine.
So my lack of repair mechanic experience, would make me simply check the condition of the chain, check the front and rear sprocket its connected to.
____________________
Honda CG125 Website https://hondacg125.awardspace.com/
Honda CBF125, CBR125 & Yamaha YBR125 Website https://125ccbikeclub.awardspace.co.uk/
I have left bikechat forums, I do not read pm (Private Message)

[virus]

first things first, strip the eintire chainguard off (known for causing un nerving grinding noises if the chain hits. take of the chain an front sprocket cover, clean the chain, put back on, lube heavily and set to correct slack. if the sprocket shaft and seal look good then go for a spin around the block (after putting side case back on) and work up through the gears, try to be as smooth as possible because if your jumpy with the clutch the cg will grind anyway.

then come post what happened

Cheers
John
____________________
own: 81 xs1100g...
owned: 85 rat CG (sold), 91 GS500e (stolen), 84 gsx400f (scrapped), 81 z250 (siezed, siezed, scrapped), 83 cb250rs (sold), 84 gpz750r ratfighter (killed) 84gpz400 (sold), '80 cb650 ratfighter (wrote off) 95gsx6/12f ratfighter (killed) 91 xj900 (sold)
stinkwheel Well I just had my hands up a pigs fanny. Which makes your concerns pale into insignificance.