Get yourself a Haynes manual, will have all the information you need.

No spark, first rule would be side-stand switch. If that doesn't do it you will have to work your way from the battery to the spark plug itself.

https://www.amazon.co.uk/Yamaha-TZR125-1987-1993-DT125R/dp/184425626X/ref=sr_1_fkmrnull_1?keywords=haynes+dt125r&qid=1558425286&s=gateway&sr=8-1-fkmrnull

@dtStevie98 Yeah, that looks completely different mate sorry. Still for £30 it's pretty cheap.

Hiya, welcome

Good looking bike, definitely a good base by looks of it. Then again not a lot can go wrong with these.

Nice. Why not just get a DT200R if you wanted a 200cc? It wouldn't be 98 but... or just buy a 200cc DT engine and fit it into your 125, if I remember right it's a straight bolt-in.

Welcome! Send some pictures of your bikes

Goes to France to work on the house, buys a bike instead

Well, I found the one I was looking at earlier and got my hands on it. What a machine!