I've just got a 1979 Yamaha Rs 100. I'm new to bikes and know pretty much nothing about them mechanically. On first starting it started fine but was on reserve fuel, after a few hundred yards (on the way to fill up) she spluttered, banged and stopped and upon filling up has refused to start again.

Rubbish in the fuel tank has got to somewhere it shouldn't have?

Any suggestions would be gratefully recieved!

I've just got a 1979 Yamaha Rs 100. I'm new to bikes and know pretty much nothing about them mechanically. On first starting it started fine but was on reserve fuel, after a few hundred yards (on the way to fill up) she spluttered, banged and stopped and upon filling up has refused to start again.

Rubbish in the fuel tank has got to somewhere it shouldn't have?

Any suggestions would be gratefully recieved!

Welcome 'bikedog'

First pull off the fuel pipe from the carb and verify that there is a good flow of fuel, then replace it try again (use choke). Failing this check for spark and if ok then perhaps youre looking at a carb strip / clean

...Paul

Welcome 'bikedog'

First pull off the fuel pipe from the carb and verify that there is a good flow of fuel, then replace it try again (use choke). Failing this check for spark and if ok then perhaps youre looking at a carb strip / clean

...Paul

Thanks paul,

Is a carb strip/clean an easy thing for a beginner to attempt?

r.

Thanks paul,

Is a carb strip/clean an easy thing for a beginner to attempt?

r.

I suppose not, a beginner may have difficulty even removing a screw that is jammed

before you rush into that do the fuel flow test and check for a good spark, to do that remove the spark plug then fit it back into the plug cap and rest it onto the cylinder head while you kick the engine over with the ignition on...watch for a spark (keep your fingers away...it hurts)

Wilkommen Dog, these are super-simple bikes but carbs can be tricky. If you find that gas is not getting down to teh carb as OldGit suggested, see if you can safely siphon the gas out of the tank and unscrew the petcock (fuel valve). It may have garbage packed up around it blocking fuel flow, get a can of computer keyboard cleaner (compressed air basically) and blast air up into the pipe that the fuel line connects to. Set the valve at different positions to clear all the passages inside. Think of it this way, pretend you are trying to blow air INTO the tank through that valve.

If there is flow from the tank to the carb, and you have a good spark, the next step is to check compression. Rent/borrow/buy a compression tester and give it a whirl. You should have at least 115-120 psi to get it running. If you are there, then you will need to take the carb off and clean the heck out of it. It is very common for a bike that has sat a long time to need a carb cleaning. In fact, if you do not feel confident enough to take it apart, but are brave enough to pull it from the bike, no shame in taking just the carb to a bike shop. Shouldn't cost too much, and it takes about a day as the parts have to soak in solution.

Good luck, post up pictures if you got 'em.