Hi guys .. I just joined the forum .. I've had a look at previous posts and I couldn't find anything that answers my question .. but apologies if I've missed it. I am using a 2006 VTR1000F motor in a hill climb car I am building . I just love this engine !!! . I bought the engine a few years ago and have run it a few times to make sure it was working. But just in the last couple of days I tried to start it and it wouldn't start. The electrics are all OK, and it fires up fine if I tip a spoon full of gas down the carbs, but dies after a few seconds. It runs a bit longer if I use the "choke". But basically, it seems to me that the carb is just not delivering fuel into the throat of the carb. Why? There is fuel in the float chambers. I have cleaned out all the jets I could find. If I put a bit of air pressure into the breather(?) tube then fuel comes out past the needle. As you can see this carb is new territory for me. The next steps I plan are to check the fuel level in the float chamber, and the path from the emulsion tube to the needle. But feel I am missing something critical . I'm not expecting it to run perfectly.. but I can't see what is stopping it from simply firing up in the normal fashion. Suggestions very welcome.
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If it runs longer on the choke, it's not getting enough fuel at idle. If you've confirmed the pilot jet/idle circuit is clean and flowing fuel, it could be a few things including float height too low, air leak at the carb boots, or throttle plate (idle adjuster) not opened enough to establish high enough idle speed to run.

 

It sounds like the carbs are dirty.
Pilot circuit is very small. it takes only a bit of evaporated gas byproducts to plug the circuit.
Id start with pulling carb set, and cleaning them....that means different things to different persons.. They need to be completely dissembled, id recommenced a 30 min bath in a heated sonic tank with the proper soap, then flush carbs, clean and dry, then check all circuits with air and brake cleaner
If your not able to do that detail of a cleaning farm it out.

 

Thanks for your suggestions. I will look into that.