I noticed that I had a little petrol come out of this hole When I turned the fuel on. I had only just cleaned the carb it stopped after a few secs and hasn't done it since. as you sit on the bike this hole is on the right hand side of the carb on the bottom of the float bowl. I think it's for a pipe I didn't see a pipe on it when I pulled the carb.. Anyone know if this is for a pipe and if so does anyone know the diameter or have any I can have pretty please?
Cheers mate. That's a good diagram you have there actually. better check it ain't missing anything else. I did notice that when I pulled the choke out it didn't really engage that well when pulled right out you kind of have to find a sweet spot..i unscrewed it to check it and noticed that there is a little clip in there same as whats on a carb needle. does that do anything?
checked the fowlers parts thing but they are out of stock...
Brian do you have one!
Only just seen your post - will have a look tomorrow. The likelihood is that I have one.
The pipe can be tricky to fit to the carb unless you have tiny hands or are triple jointed!
Just for info, here is a pick of the drain/breather pipes that run up to the airbox.
Over the years, crud falls into the pipes and can affect the operation of the one-way valves (indicated by purple arrows) so best to do the suck/blow test to make sure they are OK. Don't try sticking anything up them if they don't work coz that will damage them. Soak and clean them as best you can without getting physical
It's a C clip that acts as a stop for the spring that fits inside the sprung end of the choke that goes into the carb body.
Not noticed before but there are two further grooves that it could sit on but not sure they are deep enough for the clip. But why would it be adjustable
Brian does the check valve serve a purpose? Mine seems to be missing
Do you mean the one-way valves in my photo? If so, they allow petrol or any other fluid that gets into the lines out without letting water back in. Lots of dirt bikes don't have them and trail open pipes down low that can suck up water into the carb or just stop the bike working. The early WR400s suffered particularly with this.
The check valve is a one-way valve that sits below the accelerator pump pipe that sprays petrol into the carb mouth. Mr Yamaha doesn't put unnecessary parts in his bikes so my guess is that the accelerator pump won't operate properly with out it.