Need Some Advise

So bought a 1996 yamaha thundercat for cheap and had it sat in my dads garage until I passed my test. Went round and tried the bike out a few times worked fine apart from having to replace the battery. Fast forward a year I've finally passed my mod 2 and are now riding the bike to use daily. Unfortunately I have encountered a few issues. First issue is it won't start without a jump start pretty much or if I'm lucky just a few tries with a normal start then after being ridden a bit will start no problem. Any advise or info on why this is happening please let me know a friend thinks the crank shaft is just not turning over. Second and the more serious one is that when on my way home the bike has completely lost power even when travelling at speed and will need to be turned on again which sometimes doesn't happen. The best way I can describe it is the bike starts to sorta jolt forward and the revs start to jump a little then power completely cuts. I'm no bike expert and only know basic maintenance stuff but i feel like this is something more in depth than just an oil change. Any advise or tips or story's similar to mine and how you fixed it would be greatly appreciated.

Hi, welcome. Congrats on getting your license.

Your problems, to me, seem to be electrical. When you say jump start, is that with jump cables or pushing the bike?

You mention changing the battery, it is worth having it checked to ensure it is OK. If you left the battery go flat for a period of time it can die, likewise leaving it permanently on a charger can also kill it.

Check the battery terminals, make sure they are clean and there is no white stuff accumulated, then check that the screws are not loose.

Thanks for the reply. A friend also suggested this because I noticed my problems started after having the bike put through a pretty long jet wash and I did maybe go a bit overkill trying to clean every nook and cranny on bike so I might have just caused damage to the electrics somewhere.

Just checking (and not trying to insult you), are you aware of the choke? When your bike is started from cold you'll need to pull the choke and allow it to warm for a little bit then then ease off after that the bike will start fine from warm.

Don't worry about I understand people overlook the simplest things like choke and if there's fuel in the tank but no choke is always fully on and there's fuel in the tank. Just think the carbs need a good clean and balancing, probably something blocking the jets aswell like gunk or debree.

Could be worth trying a good dose of fuel system cleaner like redex or similar, might not cure if if the carbs are very blocked, may improve it a bit though.

Ye, I second that. I used Profi Fuel Max its really good stuff. And for £15 it's worth a go before getting carbs cleaned etc