Chain keeps breaking

[nandom ruth]

my daughter is in far northern Ghana. She has a Yamaha 4 stroke active motocross for her work on mainly dirt roads. Recently, the chain has broken while just riding along. It has been replaced (not with a yamaha chain) and I think but I am not sure, links replaced by a local mechanic. But it keeps breaking.
She is a first time biker and I know nothing. But this is a serous matter.
What could be wrong with her machine. Someone said something about sprockets. What maintenance should she do on her chain once she has it sorted ? Thanks very much indeed.

[Gadjet]

Given her location, she's likely riding in a lot of dust and dirt, so daily cleaning and lubing of the chain is recommended. Inspect the sprockets for wear, and if they are worn then they should be replaced. Best to replace the chain and sprockets as a set. Make sure that chain tension is set with the proper amount of slack - if it's too tight, then it will wear the chain and sprockets faster and lead to a broken chain or worse (damaged output shaft seals)

If the local mechanics are using cheap industrial roller chain instead of a proper motorcycle chain, then this will also accelerate wear - industrial roller chains aren't built to take the stress that a motorcycle puts on them. (I know from experience)

What kind of bike is it? If someone on the boards here has the same bike, they may be able to tell you what the proper chain tension should be, and you can pass that along to your daughter.

[Johnj]

Also check to make sure the rear wheel is square in the swing arm.