jahafd wrote:
I have a 2001 /1600. Recently I had some backfire issues and decided to clean out the carb. I found a lot of oil in the carb from the vent tube spitting back over the years. I pulled the carb completely apart and cleaned it in a chem bath. I put it back together with new jets and now it will only start and run for a little while when the choke is pulled out (engaged) all the way.
Any ideas? I saw a few posts that said never remove the throttle sensor..... I did.

Its not a problem to remove the throttle sensor, just requires that it be set back using Yamaha recommended procedures when re-attached. Most will recommend against it because the re-attachment requires knowing how to use a VOM to calibrate it.

But that would not cause the problem you are talking about. The tps only has one job, it switches the ignitor (ignition) from advanced timing curve to retarted timing curve under moderate to high acceleration. Neither curve would cause this problem.

It sounds like something got messed up. Their are quite a few pinholes in the throat of the carb, on the bottom under the valve, that need to be clear for the pilot circuit to operate properly. There is also a air duct going to the front of the carb that feeds the pilot. Then of course the pilot jet needs to be clear. The fuel provided by the enriching (choke) circuit does not come through the pilot jet, so if the jet is not sufficiently clear choking it up would add additional fuel to the circuit.

Just some food for thought.

Hang in there. Also make sure you don't have any leaks in the passing enricher (the white plastic cap on the left side).

Gram