TTR-125L - starting troubles

[Metastable]

OK - so my wife's bike won't start. It's a relatively low mileage bike that has been run fairly sedately. 1 cylinder, 4 stroke, carburated and air cooled. I'm pretty sure the battery is dead, but it has a kick starter as well, so I assume I don't really need the battery. When I try to kick start it or bump start it, there is no sign of ignition. I pulled the plug and it smells like fuel and is wet. I don't think it's oil, pretty sure it is wet with fuel and the blackness is from it being sooty. I looked inside where the spark plug goes with a filament light and it looks like the bike is running rich (but I couldn't really get a great look). I cleaned up the spark plug and tested for a spark. It sparks.... put it back in and nothing. Pull the spark plug out after a few more kick start attempts and it's wet and sooty again. I took the plug out, and with the plug out kicked the bike slowly a couple of times to air out the cylinder and kept the spark plug out for a little while. Tried again a bit later and no dice. Spark plug was sooty/wet and smelled of gas.

Bike was put away and hasn't been used in about 1 year..... pretty sure I put fuel stabilizer in the bike. It seemed to be running fine when I put the bike away. I checked the air filter and it's nice and clean.


Not sure where to go from here. Suggestions?

- I can try to siphon the fuel out and try newer fuel, clean out the carb and see if anything seems odd in there...

[OddDuck]

You'll need the battery. The coils have to be energised from somewhere and the generator won't be supplying voltage until the motor is already turning over.

Suggestions:

1) Drain fuel tank, drain carb bowls, refill with completely fresh petrol. Unleaded tends to go stale fast.

2) Fully charge battery (overnight, and check electrolyte levels too if necessary), get multimeter, check voltage at battery terminals with the bike ignition switched on, headlights off, but motor not kicked over yet. If the voltage is dropping like a stone then the battery is shot, replace it before proceeding.

3) Fresh spark plug. If they've gone sooty then you're losing electrical energy across the carbon fouling, and starting from cold, you need every bit of that spark.

4) If possible, put the bike out into the sunshine and warm everything up for about an hour before starting. Warm helps.

Good luck :niceone:

[Metastable]

Cleaned the carb, bit of dirt in there, put new petrol, cleaned off spark plug again.... BRAP.... on first bump start. Battery is not strong enough to turn the engine over, but little led lights still run.

[F5 Dave]

Next time you leave it (assume everytime if only used occasionally) run the carb bowl empty. The pilot jet tends to get blocked as its the smallest. Light end gasses disappear first from the petrol and they are the ones that help starting. Plastic tanks breathe.
Sparkplugs that spark in the open often fail in combustion chamber. Don't be a cheaparse and buy a new one.

Tight valves can make starting difficult, and obviously aren't good long term.