Peter T

It sounds like electrical to me, if it starts fine by bumping it then every other component works, so leave alone for now. If the starter is turning the engine then you need to see if the coil is getting 12 volts while cranking, if not then there are two possibilities. 1- the starter solonoid is knackered. 2- The starter switch on the handlebar is not making good contact, this can be checked and cleaned to eliminate this. If you are good at wiring then take a feed from the battery staright to the coil and see if this works...... if so it is your solonoid.

Did you check that the jet sizes in the carb you put on are the same as the one you took off? This would be the first thing to check.

Any Yamaha dealer, i bought two new ones for around £9.

You need to assertain whether you need a 2 wire version or the later 5 wire version which has different cables also. Look to see what connector block yours have before buying. 5 wire versions are common on e-bay but the two wire versions are harder to come by.

Water in the fuel tank does not help also, i found that condensation in the fuel tank over 6 months finds it's way through the filters and sits in the lower bowl of the float chamber in the carburettor, the main jet will not pull the water through as it is heavier than fuel. A quick test to see if you have contaminated fuel is to drain of some into a milk bottle and let it settle, the water will sit in the bottom if you have any in your fuel tank. You can try draining the carb via the drain screw located in the float chamber first before removing the entire carb.

Yes!! Just goes to show that some problems are not always related and you have to do some lateral thinking sometimes.

Have you changed the oil recently? I had a similar problem with clutch dragging and not dissengaging after trying some synthetic oil?

Problem solved!!! I renewed the gearbox oil before i started to semi strip it down, and realised after using a paddock stand that the backwheel was spinning? After applying the brake i soon found that the clutch was dragging badly which is why it would not start easily. Strange as it was Semi synthetic oil that was advised by a Yamaha dealer. Going to try some non synthetic oil.

Thanks for the welcome. That was my first thought but have tried that and it is a new battery.

I have a 2004 DT electric start model which does not start while cranking. It only seems to start when the button is released? Is there a relay that controls the starting coil while cranking? Thanks.